The assumption in __disable_kprobe() is wrong, and it could try to disarm
an already disarmed kprobe and fire the WARN_ONCE() below. [0] We can
easily reproduce this issue.
1. Write 0 to /sys/kernel/debug/kprobes/enabled.
# echo 0 > /sys/kernel/debug/kprobes/enabled
2. Run execsnoop. At this time, one kprobe is disabled.
# /usr/share/bcc/tools/execsnoop &
[1] 2460
PCOMM PID PPID RET ARGS
# cat /sys/kernel/debug/kprobes/list ffffffff91345650 r __x64_sys_execve+0x0 [FTRACE] ffffffff91345650 k __x64_sys_execve+0x0 [DISABLED][FTRACE]
3. Write 1 to /sys/kernel/debug/kprobes/enabled, which changes
kprobes_all_disarmed to false but does not arm the disabled kprobe.
# echo 1 > /sys/kernel/debug/kprobes/enabled
# cat /sys/kernel/debug/kprobes/list ffffffff91345650 r __x64_sys_execve+0x0 [FTRACE] ffffffff91345650 k __x64_sys_execve+0x0 [DISABLED][FTRACE]
4. Kill execsnoop, when __disable_kprobe() calls disarm_kprobe() for the
disabled kprobe and hits the WARN_ONCE() in __disarm_kprobe_ftrace().
# fg
/usr/share/bcc/tools/execsnoop
^C
Actually, WARN_ONCE() is fired twice, and __unregister_kprobe_top() misses
some cleanups and leaves the aggregated kprobe in the hash table. Then,
__unregister_trace_kprobe() initialises tk->rp.kp.list and creates an
infinite loop like this.
anon_vma->degree tracks the combined number of child anon_vmas and VMAs
that use the anon_vma as their ->anon_vma.
anon_vma_clone() then assumes that for any anon_vma attached to
src->anon_vma_chain other than src->anon_vma, it is impossible for it to
be a leaf node of the VMA tree, meaning that for such VMAs ->degree is
elevated by 1 because of a child anon_vma, meaning that if ->degree
equals 1 there are no VMAs that use the anon_vma as their ->anon_vma.
This assumption is wrong because the ->degree optimization leads to leaf
nodes being abandoned on anon_vma_clone() - an existing anon_vma is
reused and no new parent-child relationship is created. So it is
possible to reuse an anon_vma for one VMA while it is still tied to
another VMA.
This is an issue because is_mergeable_anon_vma() and its callers assume
that if two VMAs have the same ->anon_vma, the list of anon_vmas
attached to the VMAs is guaranteed to be the same. When this assumption
is violated, vma_merge() can merge pages into a VMA that is not attached
to the corresponding anon_vma, leading to dangling page->mapping
pointers that will be dereferenced during rmap walks.
Fix it by separately tracking the number of child anon_vmas and the
number of VMAs using the anon_vma as their ->anon_vma.
Fixes: 7a3ef208e662 ("mm: prevent endless growth of anon_vma hierarchy") Cc: stable@kernel.org Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[manually fixed up different indentation in stable] Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently in arm64, FDT is mapped to RO before it's passed to
early_init_dt_scan(). However, there might be some codes
(eg. commit "fdt: add support for rng-seed") that need to modify FDT
during init. Map FDT to RO after early fixups are done.
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Will Deacon <will@kernel.org>
[mkbestas: fixed trivial conflicts for 4.9 backport] Signed-off-by: Michael Bestas <mkbestas@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ftrace_startup does not remove ops from ftrace_ops_list when
ftrace_startup_enable fails:
register_ftrace_function
ftrace_startup
__register_ftrace_function
...
add_ftrace_ops(&ftrace_ops_list, ops)
...
...
ftrace_startup_enable // if ftrace failed to modify, ftrace_disabled is set to 1
...
return 0 // ops is in the ftrace_ops_list.
When ftrace_disabled = 1, unregister_ftrace_function simply returns without doing anything:
unregister_ftrace_function
ftrace_shutdown
if (unlikely(ftrace_disabled))
return -ENODEV; // return here, __unregister_ftrace_function is not executed,
// as a result, ops is still in the ftrace_ops_list
__unregister_ftrace_function
...
If ops is dynamically allocated, it will be free later, in this case,
is_ftrace_trampoline accesses NULL pointer:
is_ftrace_trampoline
ftrace_ops_trampoline
do_for_each_ftrace_op(op, ftrace_ops_list) // OOPS! op may be NULL!
In `do_fb_ioctl()` of fbmem.c, if cmd is FBIOPUT_VSCREENINFO, var will be
copied from user, then go through `fb_set_var()` and
`info->fbops->fb_check_var()` which could may be `pm2fb_check_var()`.
Along the path, `var->pixclock` won't be modified. This function checks
whether reciprocal of `var->pixclock` is too high. If `var->pixclock` is
zero, there will be a divide by zero error. So, it is necessary to check
whether denominator is zero to avoid crash. As this bug is found by
Syzkaller, logs are listed below.
The error handling code in pvr2_hdw_create forgets to unregister the
v4l2 device. When pvr2_hdw_create returns back to pvr2_context_create,
it calls pvr2_context_destroy to destroy context, but mp->hdw is NULL,
which leads to that pvr2_hdw_destroy directly returns.
Fix this by adding v4l2_device_unregister to decrease the refcount of
usb interface.
Reported-by: syzbot+77b432d57c4791183ed4@syzkaller.appspotmail.com Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When building an external module, if users don't need to separate the
compilation output and source code, they run the following command:
"make -C $(LINUX_SRC_DIR) M=$(PWD)". At this point, "$(KBUILD_EXTMOD)"
and "$(src)" are the same.
If they need to separate them, they run "make -C $(KERNEL_SRC_DIR)
O=$(KERNEL_OUT_DIR) M=$(OUT_DIR) src=$(PWD)". Before running the
command, they need to copy "Kbuild" or "Makefile" to "$(OUT_DIR)" to
prevent compilation failure.
So the kernel should change the included path to avoid the copy operation.
Signed-off-by: Jing Leng <jleng@ambarella.com>
[masahiro: I do not think "M=$(OUT_DIR) src=$(PWD)" is the official way,
but this patch is a nice clean up anyway.] Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
[nsc: updated context for v4.19] Signed-off-by: Nicolas Schier <n.schier@avm.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Older Intel CPUs that are not in the affected processor list for MMIO
Stale Data vulnerabilities currently report "Not affected" in sysfs,
which may not be correct. Vulnerability status for these older CPUs is
unknown.
Add known-not-affected CPUs to the whitelist. Report "unknown"
mitigation status for CPUs that are not in blacklist, whitelist and also
don't enumerate MSR ARCH_CAPABILITIES bits that reflect hardware
immunity to MMIO Stale Data vulnerabilities.
Mitigation is not deployed when the status is unknown.
[ bp: Massage, fixup. ]
Fixes: 8d50cdf8b834 ("x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale Data") Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com> Suggested-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/a932c154772f2121794a5f2eded1a11013114711.1657846269.git.pawan.kumar.gupta@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For non-protection pXd_none() page faults in do_dat_exception(), we
call do_exception() with access == (VM_READ | VM_WRITE | VM_EXEC).
In do_exception(), vma->vm_flags is checked against that before
calling handle_mm_fault().
Since commit 92f842eac7ee3 ("[S390] store indication fault optimization"),
we call handle_mm_fault() with FAULT_FLAG_WRITE, when recognizing that
it was a write access. However, the vma flags check is still only
checking against (VM_READ | VM_WRITE | VM_EXEC), and therefore also
calling handle_mm_fault() with FAULT_FLAG_WRITE in cases where the vma
does not allow VM_WRITE.
Fix this by changing access check in do_exception() to VM_WRITE only,
when recognizing write access.
Some drivers rely on having all VMAs through which a PFN might be
accessible listed in the rmap for correctness.
However, on X86, it was possible for a VMA with stale TLB entries
to not be listed in the rmap.
This was fixed in mainline with
commit b67fbebd4cf9 ("mmu_gather: Force tlb-flush VM_PFNMAP vmas"),
but that commit relies on preceding refactoring in
commit 18ba064e42df3 ("mmu_gather: Let there be one tlb_{start,end}_vma()
implementation") and commit 1e9fdf21a4339 ("mmu_gather: Remove per arch
tlb_{start,end}_vma()").
This patch provides equivalent protection without needing that
refactoring, by forcing a TLB flush between removing PTEs in
unmap_vmas() and the call to unlink_file_vma() in free_pgtables().
[This is a stable-specific rewrite of the upstream commit!] Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Patch series "mm/hugetlb: fix write-fault handling for shared mappings", v2.
I observed that hugetlb does not support/expect write-faults in shared
mappings that would have to map the R/O-mapped page writable -- and I
found two case where we could currently get such faults and would
erroneously map an anon page into a shared mapping.
Reproducers part of the patches.
I propose to backport both fixes to stable trees. The first fix needs a
small adjustment.
This patch (of 2):
Staring at hugetlb_wp(), one might wonder where all the logic for shared
mappings is when stumbling over a write-protected page in a shared
mapping. In fact, there is none, and so far we thought we could get away
with that because e.g., mprotect() should always do the right thing and
map all pages directly writable.
Above test fails with SIGBUS when there is only a single free hugetlb page.
# echo 1 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
# ./test
Bus error (core dumped)
And worse, with sufficient free hugetlb pages it will map an anonymous page
into a shared mapping, for example, messing up accounting during unmap
and breaking MAP_SHARED semantics:
# echo 2 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
# ./test
# cat /proc/meminfo | grep HugePages_
HugePages_Total: 2
HugePages_Free: 1
HugePages_Rsvd: 18446744073709551615
HugePages_Surp: 0
Reason in this particular case is that vma_wants_writenotify() will
return "true", removing VM_SHARED in vma_set_page_prot() to map pages
write-protected. Let's teach vma_wants_writenotify() that hugetlb does not
support softdirty tracking.
Link: https://lkml.kernel.org/r/20220811103435.188481-1-david@redhat.com Link: https://lkml.kernel.org/r/20220811103435.188481-2-david@redhat.com Fixes: 64e455079e1b ("mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared") Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Peter Feiner <pfeiner@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Jamie Liu <jamieliu@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: <stable@vger.kernel.org> [3.18+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are two problems with the current code of memory_intersects:
First, it doesn't check whether the region (begin, end) falls inside the
region (virt, vend), that is (virt < begin && vend > end).
The second problem is if vend is equal to begin, it will return true but
this is wrong since vend (virt + size) is not the last address of the
memory region but (virt + size -1) is. The wrong determination will
trigger the misreporting when the function check_for_illegal_area calls
memory_intersects to check if the dma region intersects with stext region.
The misreporting is as below (stext is at 0x80100000):
WARNING: CPU: 0 PID: 77 at kernel/dma/debug.c:1073 check_for_illegal_area+0x130/0x168
DMA-API: chipidea-usb2 e0002000.usb: device driver maps memory from kernel text or rodata [addr=800f0000] [len=65536]
Modules linked in:
CPU: 1 PID: 77 Comm: usb-storage Not tainted 5.19.0-yocto-standard #5
Hardware name: Xilinx Zynq Platform
unwind_backtrace from show_stack+0x18/0x1c
show_stack from dump_stack_lvl+0x58/0x70
dump_stack_lvl from __warn+0xb0/0x198
__warn from warn_slowpath_fmt+0x80/0xb4
warn_slowpath_fmt from check_for_illegal_area+0x130/0x168
check_for_illegal_area from debug_dma_map_sg+0x94/0x368
debug_dma_map_sg from __dma_map_sg_attrs+0x114/0x128
__dma_map_sg_attrs from dma_map_sg_attrs+0x18/0x24
dma_map_sg_attrs from usb_hcd_map_urb_for_dma+0x250/0x3b4
usb_hcd_map_urb_for_dma from usb_hcd_submit_urb+0x194/0x214
usb_hcd_submit_urb from usb_sg_wait+0xa4/0x118
usb_sg_wait from usb_stor_bulk_transfer_sglist+0xa0/0xec
usb_stor_bulk_transfer_sglist from usb_stor_bulk_srb+0x38/0x70
usb_stor_bulk_srb from usb_stor_Bulk_transport+0x150/0x360
usb_stor_Bulk_transport from usb_stor_invoke_transport+0x38/0x440
usb_stor_invoke_transport from usb_stor_control_thread+0x1e0/0x238
usb_stor_control_thread from kthread+0xf8/0x104
kthread from ret_from_fork+0x14/0x2c
Refactor memory_intersects to fix the two problems above.
Before the 1d7db834a027e ("dma-debug: use memory_intersects()
directly"), memory_intersects is called only by printk_late_init:
There were few places where memory_intersects was called.
When commit 1d7db834a027e ("dma-debug: use memory_intersects()
directly") was merged and CONFIG_DMA_API_DEBUG is enabled, the DMA
subsystem uses it to check for an illegal area and the calltrace above
is triggered.
The userspace can configure a loop using an ioctl call, wherein
a configuration of type loop_config is passed (see lo_ioctl()'s
case on line 1550 of drivers/block/loop.c). This proceeds to call
loop_configure() which in turn calls loop_set_status_from_info()
(see line 1050 of loop.c), passing &config->info which is of type
loop_info64*. This function then sets the appropriate values, like
the offset.
loop_device has lo_offset of type loff_t (see line 52 of loop.c),
which is typdef-chained to long long, whereas loop_info64 has
lo_offset of type __u64 (see line 56 of include/uapi/linux/loop.h).
The function directly copies offset from info to the device as
follows (See line 980 of loop.c):
lo->lo_offset = info->lo_offset;
This results in an overflow, which triggers a warning in iomap_iter()
due to a call to iomap_iter_done() which has:
WARN_ON_ONCE(iter->iomap.offset > iter->pos);
Thus, check for negative value during loop_set_status_from_info().
For a filesystem which has btrfs read-only property set to true, all
write operations including xattr should be denied. However, security
xattr can still be changed even if btrfs ro property is true.
This happens because xattr_permission() does not have any restrictions
on security.*, system.* and in some cases trusted.* from VFS and
the decision is left to the underlying filesystem. See comments in
xattr_permission() for more details.
This patch checks if the root is read-only before performing the set
xattr operation.
The ixgbe_ptp_start_cyclecounter is intended to be called whenever the
cyclecounter parameters need to be changed.
Since commit a9763f3cb54c ("ixgbe: Update PTP to support X550EM_x
devices"), this function has cleared the SYSTIME registers and reset the
TSAUXC DISABLE_SYSTIME bit.
While these need to be cleared during ixgbe_ptp_reset, it is wrong to clear
them during ixgbe_ptp_start_cyclecounter. This function may be called
during both reset and link status change. When link changes, the SYSTIME
counter is still operating normally, but the cyclecounter should be updated
to account for the possibly changed parameters.
Clearing SYSTIME when link changes causes the timecounter to jump because
the cycle counter now reads zero.
Extract the SYSTIME initialization out to a new function and call this
during ixgbe_ptp_reset. This prevents the timecounter adjustment and avoids
an unnecessary reset of the current time.
This also restores the original SYSTIME clearing that occurred during
ixgbe_ptp_reset before the commit above.
Reported-by: Steve Payne <spayne@aurora.tech> Reported-by: Ilya Evenbach <ievenbach@aurora.tech> Fixes: a9763f3cb54c ("ixgbe: Update PTP to support X550EM_x devices") Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel) Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
While reading sysctl_tstamp_allow_data, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its reader.
Fixes: b245be1f4db1 ("net-timestamp: no-payload only sysctl") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
While reading rs->interval and rs->burst, they can be changed
concurrently via sysctl (e.g. net_ratelimit_state). Thus, we
need to add READ_ONCE() to their readers.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
This is caused by the global variable ad_ticks_per_sec being zero as
demonstrated by the reproducer script discussed below. This causes
all timer values in __ad_timer_to_ticks to be zero, resulting
in the periodic timer to never fire.
To reproduce:
Run the script in
`tools/testing/selftests/drivers/net/bonding/bond-break-lacpdu-tx.sh` which
puts bonding into a state where it never transmits LACPDUs.
line 44: ip link add fbond type bond mode 4 miimon 200 \
xmit_hash_policy 1 ad_actor_sys_prio 65535 lacp_rate fast
setting bond param: ad_actor_sys_prio
given:
params.ad_actor_system = 0
call stack:
bond_option_ad_actor_sys_prio()
-> bond_3ad_update_ad_actor_settings()
-> set ad.system.sys_priority = bond->params.ad_actor_sys_prio
-> ad.system.sys_mac_addr = bond->dev->dev_addr; because
params.ad_actor_system == 0
results:
ad.system.sys_mac_addr = bond->dev->dev_addr
line 48: ip link set fbond address 52:54:00:3B:7C:A6
setting bond MAC addr
call stack:
bond->dev->dev_addr = new_mac
line 52: ip link set fbond type bond ad_actor_sys_prio 65535
setting bond param: ad_actor_sys_prio
given:
params.ad_actor_system = 0
call stack:
bond_option_ad_actor_sys_prio()
-> bond_3ad_update_ad_actor_settings()
-> set ad.system.sys_priority = bond->params.ad_actor_sys_prio
-> ad.system.sys_mac_addr = bond->dev->dev_addr; because
params.ad_actor_system == 0
results:
ad.system.sys_mac_addr = bond->dev->dev_addr
line 60: ip link set veth1-bond down master fbond
given:
params.ad_actor_system = 0
params.mode = BOND_MODE_8023AD
ad.system.sys_mac_addr == bond->dev->dev_addr
call stack:
bond_enslave
-> bond_3ad_initialize(); because first slave
-> if ad.system.sys_mac_addr != bond->dev->dev_addr
return
results:
Nothing is run in bond_3ad_initialize() because dev_addr equals
sys_mac_addr leaving the global ad_ticks_per_sec zero as it is
never initialized anywhere else.
The if check around the contents of bond_3ad_initialize() is no longer
needed due to commit 5ee14e6d336f ("bonding: 3ad: apply ad_actor settings
changes immediately") which sets ad.system.sys_mac_addr if any one of
the bonding parameters whos set function calls
bond_3ad_update_ad_actor_settings(). This is because if
ad.system.sys_mac_addr is zero it will be set to the current bond mac
address, this causes the if check to never be true.
Fixes: 5ee14e6d336f ("bonding: 3ad: apply ad_actor settings changes immediately") Signed-off-by: Jonathan Toppins <jtoppins@redhat.com> Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Commit 3b3fd068c56e3fbea30090859216a368398e39bf added NULL check for
`rose_loopback_neigh->dev` in rose_loopback_timer() but omitted to
check rose_loopback_neigh->loopback.
It thus prevents *all* rose connect.
The reason is that a special rose_neigh loopback has a NULL device.
/proc/net/rose_neigh displays special rose_loopback_neigh->loopback as
callsign RSLOOP-0:
addr callsign dev count use mode restart t0 tf digipeaters
00001 RSLOOP-0 ??? 1 2 DCE yes 0 0
By checking rose_loopback_neigh->loopback, rose_rx_call_request() is called
even in case rose_loopback_neigh->dev is NULL. This repairs rose connections.
Verification with rose client application FPAC:
FPAC-Node v 4.1.3 (built Aug 5 2022) for LINUX (help = h)
F6BVP-4 (Commands = ?) : u
Users - AX.25 Level 2 sessions :
Port Callsign Callsign AX.25 state ROSE state NetRom status
axudp F6BVP-5 -> F6BVP-9 Connected Connected ---------
Fixes: 3b3fd068c56e ("rose: Fix Null pointer dereference in rose_send_frame()") Signed-off-by: Bernard Pidoux <f6bvp@free.fr> Suggested-by: Francois Romieu <romieu@fr.zoreil.com> Cc: Thomas DL9SAU Osterried <thomas@osterried.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
When namespace support was added to xfrm/afkey, it caused the
previously single-threaded call to xfrm_probe_algs to become
multi-threaded. This is buggy and needs to be fixed with a mutex.
The issue happens on an error path in __xfrm_policy_check(). When the
fetching process of the object `pols[1]` fails, the function simply
returns 0, forgetting to decrement the reference count of `pols[0]`,
which is incremented earlier by either xfrm_sk_policy_lookup() or
xfrm_policy_lookup(). This may result in memory leaks.
Fix it by decreasing the reference count of `pols[0]` in that path.
Fixes: 134b0fc544ba ("IPsec: propagate security module errors up from flow_cache_lookup") Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
The exception handler is broken for unaligned memory acceses with fldw
and fstw instructions, because it trashes or uses randomly some other
floating point register than the one specified in the instruction word
on loads and stores.
The instruction "fldw 0(addr),%fr22L" (and the other fldw/fstw
instructions) encode the target register (%fr22) in the rightmost 5 bits
of the instruction word. The 7th rightmost bit of the instruction word
defines if the left or right half of %fr22 should be used.
While processing unaligned address accesses, the FR3() define is used to
extract the offset into the local floating-point register set. But the
calculation in FR3() was buggy, so that for example instead of %fr22,
register %fr12 [((22 * 2) & 0x1f) = 12] was used.
This bug has been since forever in the parisc kernel and I wonder why it
wasn't detected earlier. Interestingly I noticed this bug just because
the libime debian package failed to build on *native* hardware, while it
successfully built in qemu.
This patch corrects the bitshift and masking calculation in FR3().
arch/mips/mm/tlbex.c:629:24: error: converting the result of '<<' to a boolean; did you mean '(1 << _PAGE_NO_EXEC_SHIFT) != 0'? [-Werror,-Wint-in-bool-context]
if (cpu_has_rixi && !!_PAGE_NO_EXEC) {
^
arch/mips/include/asm/pgtable-bits.h:174:28: note: expanded from macro '_PAGE_NO_EXEC'
# define _PAGE_NO_EXEC (1 << _PAGE_NO_EXEC_SHIFT)
^
arch/mips/mm/tlbex.c:2568:24: error: converting the result of '<<' to a boolean; did you mean '(1 << _PAGE_NO_EXEC_SHIFT) != 0'? [-Werror,-Wint-in-bool-context]
if (!cpu_has_rixi || !_PAGE_NO_EXEC) {
^
arch/mips/include/asm/pgtable-bits.h:174:28: note: expanded from macro '_PAGE_NO_EXEC'
# define _PAGE_NO_EXEC (1 << _PAGE_NO_EXEC_SHIFT)
^
2 errors generated.
_PAGE_NO_EXEC can be '0' or '1 << _PAGE_NO_EXEC_SHIFT' depending on the
build and runtime configuration, which is what the negation operators
are trying to convey. To silence the warning, explicitly compare against
0 so the result of the '<<' operator is not implicitly converted to a
boolean.
According to its documentation, GCC enables -Wint-in-bool-context with
-Wall but this warning is not visible when building the same
configuration with GCC. It appears GCC only warns when compiling C++,
not C, although the documentation makes no note of this:
https://godbolt.org/z/x39q3brxf
Since the user can control the arguments of the ioctl() from the user
space, under special arguments that may result in a divide-by-zero bug.
If the user provides an improper 'pixclock' value that makes the argumet
of i740_calc_vclk() less than 'I740_RFREQ_FIX', it will cause a
divide-by-zero bug in:
drivers/video/fbdev/i740fb.c:353 p_best = min(15, ilog2(I740_MAX_VCO_FREQ / (freq / I740_RFREQ_FIX)));
On 64-bit, calling jump_label_init() in setup_feature_keys() is too
late because static keys may be used in subroutines of
parse_early_param() which is again subroutine of early_init_devtree().
For example booting with "threadirqs":
static_key_enable_cpuslocked(): static key '0xc000000002953260' used before call to jump_label_init()
WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:166 static_key_enable_cpuslocked+0xfc/0x120
...
NIP static_key_enable_cpuslocked+0xfc/0x120
LR static_key_enable_cpuslocked+0xf8/0x120
Call Trace:
static_key_enable_cpuslocked+0xf8/0x120 (unreliable)
static_key_enable+0x30/0x50
setup_forced_irqthreads+0x28/0x40
do_early_param+0xa0/0x108
parse_args+0x290/0x4e0
parse_early_options+0x48/0x5c
parse_early_param+0x58/0x84
early_init_devtree+0xd4/0x518
early_setup+0xb4/0x214
So call jump_label_init() just before parse_early_param() in
early_init_devtree().
Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
[mpe: Add call trace to change log and minor wording edits.] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220726015747.11754-1-zhouzhouyi@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
For avoiding the potential deadlock via kill_fasync() call, use the
new fasync helpers to defer the invocation from PCI API. Note that
it's merely a workaround.
Currently the call of kill_fasync() from an interrupt handler might
lead to potential spin deadlocks, as spotted by syzkaller.
Unfortunately, it's not so trivial to fix this lock chain as it's
involved with the tasklist_lock that is touched in allover places.
As a temporary workaround, this patch provides the way to defer the
async signal notification in a work. The new helper functions,
snd_fasync_helper() and snd_kill_faync() are replacements for
fasync_helper() and kill_fasync(), respectively. In addition,
snd_fasync_free() needs to be called at the destructor of the relevant
file object.
We should call of_node_put() for the reference 'uctl_node' returned by
of_get_parent() which will increase the refcount. Otherwise, there will
be a refcount leak bug.
Signed-off-by: Liang He <windhl@126.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
On buffer resize failure, vfio_info_cap_add() will free the buffer,
report zero for the size, and return -ENOMEM. As additional
hardening, also clear the buffer pointer to prevent any chance of a
double free.
Signed-off-by: Schspa Shi <schspa@gmail.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/r/20220629022948.55608-1-schspa@gmail.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
This patch avoids an attempt to resize the filesystem to an
unaligned cluster boundary. An online resize to a size that is not
integral to cluster size results in the last iteration attempting to
grow the fs by a negative amount, which trips a BUG_ON and leaves the fs
with a corrupted in-memory superblock.
Now if check directoy entry is corrupted, ext4_empty_dir may return true
then directory will be removed when file system mounted with "errors=continue".
In order not to make things worse just return false when directory is corrupted.
In line 2884, "raid5_release_stripe(sh);" drops the reference to sh and
may cause sh to be released. However, sh is subsequently used in lines
2886 "if (sh->batch_head && sh != sh->batch_head)". This may result in an
use-after-free bug.
It can be fixed by moving "raid5_release_stripe(sh);" to the bottom of
the function.
Signed-off-by: Wentao_Liang <Wentao_Liang_g@163.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
In ohci_hcd_ppc_of_probe(), of_find_compatible_node() will return
a node pointer with refcount incremented. We should use of_node_put()
when it is not used anymore.
Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Liang He <windhl@126.com> Link: https://lore.kernel.org/r/20220617034637.4003115-1-windhl@126.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Fix -Woverflow warnings for tegra irqchip driver which is a result
of moving arm64 custom MMIO accessor macros to asm-generic function
implementations giving a bonus type-checking now and uncovering these
overflow warnings.
drivers/irqchip/irq-tegra.c: In function ‘tegra_ictlr_suspend’:
drivers/irqchip/irq-tegra.c:151:18: warning: large integer implicitly truncated to unsigned type [-Woverflow]
writel_relaxed(~0ul, ictlr + ICTLR_COP_IER_CLR);
^
Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Sai Prakash Ranjan <quic_saipraka@quicinc.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Marc Zyngier <maz@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
If we use the ancient SysV syscall ABI, we'd better have tell the
kernel how to claim that a negative return value is a success.
Use ->orig_r2 for that - it's inaccessible via ptrace, so it's
a fair game for changes and it's normally[*] non-negative on return
from syscall. Set to -1; syscall is not going to be restart-worthy
by definition, so we won't interfere with that use either.
[*] the only exception is rt_sigreturn(), where we skip the entire
messing with r1/r2 anyway.
There are use-after-free bugs caused by tst_timer. The root cause
is that there are no functions to stop tst_timer in idt77252_exit().
One of the possible race conditions is shown below:
This code tries to store -EFAULT in an unsigned int. The
xenbus_file_read() function returns type ssize_t so the negative value
is returned as a positive value to the user.
This change forces another change to the min() macro. Originally, the
min() macro used "unsigned" type which checkpatch complains about. Also
unsigned type would break if "len" were not capped at MAX_RW_COUNT. Use
size_t for the min(). (No effect on runtime for the min_t() change).
An O_NONBLOCK vsock_connect() request may try to reschedule
@connect_work. Imagine the following sequence of vsock_connect()
requests:
1. The 1st, non-blocking request schedules @connect_work, which will
expire after 200 jiffies. Socket state is now SS_CONNECTING;
2. Later, the 2nd, blocking request gets interrupted by a signal after
a few jiffies while waiting for the connection to be established.
Socket state is back to SS_UNCONNECTED, but @connect_work is still
pending, and will expire after 100 jiffies.
3. Now, the 3rd, non-blocking request tries to schedule @connect_work
again. Since @connect_work is already scheduled,
schedule_delayed_work() silently returns. sock_hold() is called
twice, but sock_put() will only be called once in
vsock_connect_timeout(), causing a memory leak reported by syzbot:
GPIO 31, 32 can be muxed to GCC_CAMSS_GP(1,2)_CLK respectively but the
function was never assigned to the pingroup (even though the function
exists already).
of_parse_phandle() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
Add missing of_node_put() to avoid refcount leak."
Fixes: c2f6d059abfc ("pinctrl: nomadik: refactor DT parser to take two paths") Signed-off-by: Miaoqian Lin <linmq006@gmail.com> Link: https://lore.kernel.org/r/20220607111602.57355-1-linmq006@gmail.com Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When we're reusing the backchannel requests instead of freeing them,
then we should reinitialise any values of the send/receive xdr_bufs so
that they reflect the available space.
A client should be able to handle getting an EACCES error while doing
a mount operation to reclaim state due to NFS4CLNT_RECLAIM_REBOOT
being set. If the server returns RPC_AUTH_BADCRED because authentication
failed when we execute "exportfs -au", then RECLAIM_COMPLETE will go a
wrong way. After mount succeeds, all OPEN call will fail due to an
NFS4ERR_GRACE error being returned. This patch is to fix it by resending
a RPC request.
Signed-off-by: Zhang Xianwei <zhang.xianwei8@zte.com.cn> Signed-off-by: Yi Wang <wang.yi59@zte.com.cn> Fixes: aa5190d0ed7d ("NFSv4: Kill nfs4_async_handle_error() abuses by NFSv4.1") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
clang emits a -Wunaligned-access warning on struct __packed
ems_cpc_msg.
The reason is that the anonymous union msg (not declared as packed) is
being packed right after some non naturally aligned variables (3*8
bits + 2*32) inside a packed struct:
| struct __packed ems_cpc_msg {
| u8 type; /* type of message */
| u8 length; /* length of data within union 'msg' */
| u8 msgid; /* confirmation handle */
| __le32 ts_sec; /* timestamp in seconds */
| __le32 ts_nsec; /* timestamp in nano seconds */
| /* ^ not naturally aligned */
|
| union {
| /* ^ not declared as packed */
| u8 generic[64];
| struct cpc_can_msg can_msg;
| struct cpc_can_params can_params;
| struct cpc_confirm confirmation;
| struct cpc_overrun overrun;
| struct cpc_can_error error;
| struct cpc_can_err_counter err_counter;
| u8 can_state;
| } msg;
| };
Starting from LLVM 14, having an unpacked struct nested in a packed
struct triggers a warning. c.f. [1].
Fix the warning by marking the anonymous union as packed.
During log replay, when processing inode references, if we get an error
when looking up for an extended reference at __add_inode_ref(), we ignore
it and proceed, returning success (0) if no other error happens after the
lookup. This is obviously wrong because in case an extended reference
exists and it encodes some name not in the log, we need to unlink it,
otherwise the filesystem state will not match the state it had after the
last fsync.
So just make __add_inode_ref() return an error it gets from the extended
reference lookup.
Fixes: f186373fef005c ("btrfs: extended inode refs") CC: stable@vger.kernel.org # 4.9+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The functions clear_bit and set_bit do not imply a memory barrier, thus it
may be possible that the waitqueue_active function (which does not take
any locks) is moved before clear_bit and it could miss a wakeup event.
Fix this bug by adding a memory barrier after clear_bit.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ret = -EINVAL
if (callback) {
offset = callback();
goto out;
}
...
offset = some other value in case of no callback;
ret = offset;
out:
return ret;
which causes the snd_info_entry_llseek() to return -EINVAL when there is
callback handler. Fix this by setting "ret" directly to callback return
value before jumping to "out".
Fixes: 73029e0ff18d ("ALSA: info - Implement common llseek for binary mode") Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20220817124924.3974577-1-amadeuszx.slawinski@linux.intel.com Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Follows up on:
https://lore.kernel.org/all/20220809170518.164662-1-cascardo@canonical.com/
handle of 0 implies from/to of universe realm which is not very
sensible.
Lets see what this patch will do:
$sudo tc qdisc add dev $DEV root handle 1:0 prio
//lets manufacture a way to insert handle of 0
$sudo tc filter add dev $DEV parent 1:0 protocol ip prio 100 \
route to 0 from 0 classid 1:10 action ok
//gets rejected...
Error: handle of 0 is not valid.
We have an error talking to the kernel, -1
//lets create a legit entry..
sudo tc filter add dev $DEV parent 1:0 protocol ip prio 100 route from 10 \
classid 1:10 action ok
//what did the kernel insert?
$sudo tc filter ls dev $DEV parent 1:0
filter protocol ip pref 100 route chain 0
filter protocol ip pref 100 route chain 0 fh 0x000a8000 flowid 1:10 from 10
action order 1: gact action pass
random type none pass val 0
index 1 ref 1 bind 1
//Lets try to replace that legit entry with a handle of 0
$ sudo tc filter replace dev $DEV parent 1:0 protocol ip prio 100 \
handle 0x000a8000 route to 0 from 0 classid 1:10 action drop
Error: Replacing with handle of 0 is invalid.
We have an error talking to the kernel, -1
And last, lets run Cascardo's POC:
$ ./poc
0
0
-22
-22
-22
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Ensure that the fid's iounit field is set to zero when a new fid is
created. Certain 9P operations, such as OPEN and CREATE, allow the
server to reply with an iounit size which the client code assigns to the
p9_fid struct shortly after the fid is created by p9_fid_create(). On
the other hand, an XATTRWALK operation doesn't allow for the server to
specify an iounit value. The iounit field of the newly allocated p9_fid
struct remained uninitialized in that case. Depending on allocation
patterns, the iounit value could have been something reasonable that was
carried over from previously freed fids or, in the worst case, could
have been arbitrary values from non-fid related usages of the memory
location.
The bug was detected in the Windows Subsystem for Linux 2 (WSL2) kernel
after the uninitialized iounit field resulted in the typical sequence of
two getxattr(2) syscalls, one to get the size of an xattr and another
after allocating a sufficiently sized buffer to fit the xattr value, to
hit an unexpected ERANGE error in the second call to getxattr(2). An
uninitialized iounit field would sometimes force rsize to be smaller
than the xattr value size in p9_client_read_once() and the 9P server in
WSL refused to chunk up the READ on the attr_fid and, instead, returned
ERANGE to the client. The virtfs server in QEMU seems happy to chunk up
the READ and this problem goes undetected there.
Link: https://lkml.kernel.org/r/20220710141402.803295-1-tyhicks@linux.microsoft.com Fixes: ebf46264a004 ("fs/9p: Add support user. xattr") Cc: stable@vger.kernel.org Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
[tyhicks: Adjusted context due to:
- Lack of fid refcounting introduced in v5.11 commit 6636b6dcc3db ("9p:
add refcount to p9_fid struct")
- Difference in how buffer sizes are specified v5.16 commit 6e195b0f7c8e ("9p: fix a bunch of checkpatch warnings")
- Reimplementation of the fidlist as an IDR in v4.19 commit f28cdf0430fc ("9p: Replace the fidlist with an IDR")] Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mainline crashes as follows when running nios2 images.
On node 0 totalpages: 65536
free_area_init_node: node 0, pgdat c8408fa0, node_mem_map c8726000
Normal zone: 512 pages used for memmap
Normal zone: 0 pages reserved
Normal zone: 65536 pages, LIFO batch:15
Unable to handle kernel NULL pointer dereference at virtual address 00000000
ea = c8003cb0, ra = c81cbf40, cause = 15
Kernel panic - not syncing: Oops
Problem is seen because get_cycles() is called before the timer it depends
on is initialized. Returning 0 in that situation fixes the problem.
Fixes: 33d72f3822d7 ("init/main.c: extract early boot entropy from the ..") Cc: Laura Abbott <labbott@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Daniel Micay <danielmicay@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The patch d0be8347c623: "Bluetooth: L2CAP: Fix use-after-free caused
by l2cap_chan_put" from Jul 21, 2022, leads to the following Smatch
static checker warning:
net/bluetooth/l2cap_core.c:1977 l2cap_global_chan_by_psm()
error: we previously assumed 'c' could be null (see line 1996)
Fixes: d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The usage of FLAG_SEND_ZLP causes problems to other firmware/hardware
versions that have no issues.
The FLAG_SEND_ZLP is not safe to use in this context.
See:
https://patchwork.ozlabs.org/project/netdev/patch/1270599787.8900.8.camel@Linuxdev4-laptop/#118378
The original problem needs another way to solve.
Fixes: 36a15e1cb134 ("net: usb: ax88179_178a needs FLAG_SEND_ZLP") Cc: stable@vger.kernel.org Reported-by: Ronald Wahl <ronald.wahl@raritan.com> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216327 Link: https://bugs.archlinux.org/task/75491 Signed-off-by: Jose Alonso <joalonsof@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a SCSI device is removed while in active use, currently sg will
immediately return -ENODEV on any attempt to wait for active commands that
were sent before the removal. This is problematic for commands that use
SG_FLAG_DIRECT_IO since the data buffer may still be in use by the kernel
when userspace frees or reuses it after getting ENODEV, leading to
corrupted userspace memory (in the case of READ-type commands) or corrupted
data being sent to the device (in the case of WRITE-type commands). This
has been seen in practice when logging out of a iscsi_tcp session, where
the iSCSI driver may still be processing commands after the device has been
marked for removal.
Change the policy to allow userspace to wait for active sg commands even
when the device is being removed. Return -ENODEV only when there are no
more responses to read.
Link: https://lore.kernel.org/r/5ebea46f-fe83-2d0b-233d-d0dcb362dd0a@cybernetics.com Cc: <stable@vger.kernel.org> Acked-by: Douglas Gilbert <dgilbert@interlog.com> Signed-off-by: Tony Battersby <tonyb@cybernetics.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sk_forced_mem_schedule() has a bug similar to ones fixed
in commit 7c80b038d23e ("net: fix sk_wmem_schedule() and
sk_rmem_schedule() errors")
While this bug has little chance to trigger in old kernels,
we need to fix it before the following patch.
Fixes: d83769a580f1 ("tcp: fix possible deadlock in tcp_send_fin()") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Wei Wang <weiwan@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Then even if we can only mount it RO, we will still cause metadata
update for log replay:
BTRFS info (device dm-1): flagging fs with big metadata feature
BTRFS info (device dm-1): using free space tree
BTRFS info (device dm-1): has skinny extents
BTRFS info (device dm-1): start tree-log replay
This is definitely against RO compact flag requirement.
[CAUSE]
RO compact flag only forces us to do RO mount, but we will still do log
replay for plain RO mount.
Thus this will result us to do log replay and update metadata.
This can be very problematic for new RO compat flag, for example older
kernel can not understand v2 cache, and if we allow metadata update on
RO mount and invalidate/corrupt v2 cache.
[FIX]
Just reject the mount unless rescue=nologreplay is provided:
BTRFS error (device dm-1): cannot replay dirty log with unsupport optional features (0x40000000), try rescue=nologreplay instead
We don't want to set rescue=nologreply directly, as this would make the
end user to read the old data, and cause confusion.
Since the such case is really rare, we're mostly fine to just reject the
mount with an error message, which also includes the proper workaround.
CC: stable@vger.kernel.org #4.9+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a route filter is replaced and the old filter has a 0 handle, the old
one won't be removed from the hashtable, while it will still be freed.
The test was there since before commit 1109c00547fc ("net: sched: RCU
cls_route"), when a new filter was not allocated when there was an old one.
The old filter was reused and the reinserting would only be necessary if an
old filter was replaced. That was still wrong for the same case where the
old handle was 0.
Remove the old filter from the list independently from its handle value.
This fixes CVE-2022-2588, also reported as ZDI-CAN-17440.
Reported-by: Zhenpeng Lin <zplin@u.northwestern.edu> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Reviewed-by: Kamal Mostafa <kamal@canonical.com> Cc: <stable@vger.kernel.org> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://lore.kernel.org/r/20220809170518.164662-1-cascardo@canonical.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is this warning when using a kernel with the address sanitizer
and running this testsuite:
https://gitlab.com/cki-project/kernel-tests/-/tree/main/storage/swraid/scsi_raid
==================================================================
BUG: KASAN: slab-out-of-bounds in raid_status+0x1747/0x2820 [dm_raid]
Read of size 4 at addr ffff888079d2c7e8 by task lvcreate/13319
CPU: 0 PID: 13319 Comm: lvcreate Not tainted 5.18.0-0.rc3.<snip> #1
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
Call Trace:
<TASK>
dump_stack_lvl+0x6a/0x9c
print_address_description.constprop.0+0x1f/0x1e0
print_report.cold+0x55/0x244
kasan_report+0xc9/0x100
raid_status+0x1747/0x2820 [dm_raid]
dm_ima_measure_on_table_load+0x4b8/0xca0 [dm_mod]
table_load+0x35c/0x630 [dm_mod]
ctl_ioctl+0x411/0x630 [dm_mod]
dm_ctl_ioctl+0xa/0x10 [dm_mod]
__x64_sys_ioctl+0x12a/0x1a0
do_syscall_64+0x5b/0x80
The warning is caused by reading conf->max_nr_stripes in raid_status. The
code in raid_status reads mddev->private, casts it to struct r5conf and
reads the entry max_nr_stripes.
However, if we have different raid type than 4/5/6, mddev->private
doesn't point to struct r5conf; it may point to struct r0conf, struct
r1conf, struct r10conf or struct mpconf. If we cast a pointer to one
of these structs to struct r5conf, we will be reading invalid memory
and KASAN warns about it.
Fix this bug by reading struct r5conf only if raid type is 4, 5 or 6.
If the ext4 inode does not have xattr space, 0 is returned in the
get_max_inline_xattr_value_size function. Otherwise, the function returns
a negative value when the inode does not contain EXT4_STATE_XATTR.
Cc: stable@kernel.org Signed-off-by: Baokun Li <libaokun1@huawei.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220616021358.2504451-4-libaokun1@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A race can occur in the unlikely event ext4 is unable to allocate a
physical cluster for a delayed allocation in a bigalloc file system
during writeback. Failure to allocate a cluster forces error recovery
that includes a call to mpage_release_unused_pages(). That function
removes any corresponding delayed allocated blocks from the extent
status tree. If a new delayed write is in progress on the same cluster
simultaneously, resulting in the addition of an new extent containing
one or more blocks in that cluster to the extent status tree, delayed
block accounting can be thrown off if that delayed write then encounters
a similar cluster allocation failure during future writeback.
Write lock the i_data_sem in mpage_release_unused_pages() to fix this
problem. Ext4's block/cluster accounting code for bigalloc relies on
i_data_sem for mutual exclusion, as is found in the delayed write path,
and the locking in mpage_release_unused_pages() is missing.
Cc: stable@kernel.org Reported-by: Ye Bin <yebin10@huawei.com> Signed-off-by: Eric Whitney <enwlinux@gmail.com> Link: https://lore.kernel.org/r/20220615160530.1928801-1-enwlinux@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When doing an online resize, the on-disk superblock on-disk wasn't
updated. This means that when the file system is unmounted and
remounted, and the on-disk overhead value is non-zero, this would
result in the results of statfs(2) to be incorrect.
This was partially fixed by Commits 10b01ee92df5 ("ext4: fix overhead
calculation to account for the reserved gdt blocks"), 85d825dbf489
("ext4: force overhead calculation if the s_overhead_cluster makes no
sense"), and eb7054212eac ("ext4: update the cached overhead value in
the superblock").
However, since it was too expensive to forcibly recalculate the
overhead for bigalloc file systems at every mount, this didn't fix the
problem for bigalloc file systems. This commit should address the
problem when resizing file systems with the bigalloc feature enabled.
Hulk Robot reported a issue:
==================================================================
BUG: KASAN: use-after-free in ext4_xattr_set_entry+0x18ab/0x3500
Write of size 4105 at addr ffff8881675ef5f4 by task syz-executor.0/7092
Above issue may happen as follows:
-------------------------------------
ext4_xattr_set
ext4_xattr_set_handle
ext4_xattr_ibody_find
>> s->end < s->base
>> no EXT4_STATE_XATTR
>> xattr_check_inode is not executed
ext4_xattr_ibody_set
ext4_xattr_set_entry
>> size_t min_offs = s->end - s->base
>> UAF in memcpy
we can easily reproduce this problem with the following commands:
mkfs.ext4 -F /dev/sda
mount -o debug_want_extra_isize=128 /dev/sda /mnt
touch /mnt/file
setfattr -n user.cat -v `seq -s z 4096|tr -d '[:digit:]'` /mnt/file
In ext4_xattr_ibody_find, we have the following assignment logic:
header = IHDR(inode, raw_inode)
= raw_inode + EXT4_GOOD_OLD_INODE_SIZE + i_extra_isize
is->s.base = IFIRST(header)
= header + sizeof(struct ext4_xattr_ibody_header)
is->s.end = raw_inode + s_inode_size
In the calculation formula, all values except s_inode_size and
i_extra_size are fixed values. When i_extra_size is the maximum value
s_inode_size - EXT4_GOOD_OLD_INODE_SIZE, min_offs is -4 and free is -8.
The value overflows. As a result, the preceding issue is triggered when
memcpy is executed.
Therefore, when finding xattr or setting xattr, check whether
there is space for storing xattr in the inode to resolve this issue.
Cc: stable@kernel.org Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Baokun Li <libaokun1@huawei.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220616021358.2504451-3-libaokun1@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ext4_append() must always allocate a new block, otherwise we run the
risk of overwriting existing directory block corrupting the directory
tree in the process resulting in all manner of problems later on.
Add a sanity check to see if the logical block is already allocated and
error out if it is.
When adding an xattr to an inode, we must ensure that the inode_size is
not less than EXT4_GOOD_OLD_INODE_SIZE + extra_isize + pad. Otherwise,
the end position may be greater than the start position, resulting in UAF.
Signed-off-by: Baokun Li <libaokun1@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Link: https://lore.kernel.org/r/20220616021358.2504451-2-libaokun1@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
trace_spmi_write_begin() and trace_spmi_read_end() both call
memcpy() with a length of "len + 1". This leads to one extra
byte being read beyond the end of the specified buffer. Fix
this out-of-bound memory access by using a length of "len"
instead.
Here is a KASAN log showing the issue:
BUG: KASAN: stack-out-of-bounds in trace_event_raw_event_spmi_read_end+0x1d0/0x234
Read of size 2 at addr ffffffc0265b7540 by task thermal@2.0-ser/1314
...
Call trace:
dump_backtrace+0x0/0x3e8
show_stack+0x2c/0x3c
dump_stack_lvl+0xdc/0x11c
print_address_description+0x74/0x384
kasan_report+0x188/0x268
kasan_check_range+0x270/0x2b0
memcpy+0x90/0xe8
trace_event_raw_event_spmi_read_end+0x1d0/0x234
spmi_read_cmd+0x294/0x3ac
spmi_ext_register_readl+0x84/0x9c
regmap_spmi_ext_read+0x144/0x1b0 [regmap_spmi]
_regmap_raw_read+0x40c/0x754
regmap_raw_read+0x3a0/0x514
regmap_bulk_read+0x418/0x494
adc5_gen3_poll_wait_hs+0xe8/0x1e0 [qcom_spmi_adc5_gen3]
...
__arm64_sys_read+0x4c/0x60
invoke_syscall+0x80/0x218
el0_svc_common+0xec/0x1c8
...
addr ffffffc0265b7540 is located in stack of task thermal@2.0-ser/1314 at offset 32 in frame:
adc5_gen3_poll_wait_hs+0x0/0x1e0 [qcom_spmi_adc5_gen3]
this frame has 1 object:
[32, 33) 'status'
Memory state around the buggy address: ffffffc0265b7400: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 ffffffc0265b7480: 04 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffc0265b7500: 00 00 00 00 f1 f1 f1 f1 01 f3 f3 f3 00 00 00 00
^ ffffffc0265b7580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffffc0265b7600: f1 f1 f1 f1 01 f2 07 f2 f2 f2 01 f3 00 00 00 00
==================================================================
Fixes: a9fce374815d ("spmi: add command tracepoints for SPMI") Cc: stable@vger.kernel.org Reviewed-by: Stephen Boyd <sboyd@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: David Collins <quic_collinsd@quicinc.com> Link: https://lore.kernel.org/r/20220627235512.2272783-1-quic_collinsd@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The bitops compile-time optimization series revealed one more
problem in olpc-xo1-sci.c:send_ebook_state(), resulted in GCC
warnings:
arch/x86/platform/olpc/olpc-xo1-sci.c: In function 'send_ebook_state':
arch/x86/platform/olpc/olpc-xo1-sci.c:83:63: warning: logical not is only applied to the left hand side of comparison [-Wlogical-not-parentheses]
83 | if (!!test_bit(SW_TABLET_MODE, ebook_switch_idev->sw) == state)
| ^~
arch/x86/platform/olpc/olpc-xo1-sci.c:83:13: note: add parentheses around left hand side expression to silence this warning
Despite this code working as intended, this redundant double
negation of boolean value, together with comparing to `char`
with no explicit conversion to bool, makes compilers think
the author made some unintentional logical mistakes here.
Make it the other way around and negate the char instead
to silence the warnings.
Fixes: d2aa37411b8e ("x86/olpc/xo1/sci: Produce wakeup events for buttons and switches") Cc: stable@vger.kernel.org # 3.5+ Reported-by: Guenter Roeck <linux@roeck-us.net> Reported-by: kernel test robot <lkp@intel.com> Reviewed-and-tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com> Signed-off-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Case (1):
The only waiter on wka_port->completion_wq is zfcp_fc_wka_port_get()
trying to open a WKA port. As such it should only be woken up by WKA port
*open* responses, not by WKA port close responses.
Case (2):
A close WKA port response coming in just after having sent a new open WKA
port request and before blocking for the open response with wait_event()
in zfcp_fc_wka_port_get() erroneously renders the wait_event a NOP
because the close handler overwrites wka_port->status. Hence the
wait_event condition is erroneously true and it does not enter blocking
state.
With non-negligible probability, the following time space sequence happens
depending on timing without this fix:
So we erroneously end up with no automatic port scan. This is a big problem
when it happens during boot. The timing is influenced by v3.19 commit 18f87a67e6d6 ("zfcp: auto port scan resiliency").
Fix it by fully mutually excluding zfcp_fc_wka_port_get() and
zfcp_fc_wka_port_offline(). For that to work, we make the latter block
until we got the response for a close WKA port. In order not to penalize
the system workqueue, we move wka_port->work to our own adapter workqueue.
Note that before v2.6.30 commit 828bc1212a68 ("[SCSI] zfcp: Set WKA-port to
offline on adapter deactivation"), zfcp did block in
zfcp_fc_wka_port_offline() as well, but with a different condition.
While at it, make non-functional cleanups to improve code reading in
zfcp_fc_wka_port_get(). If we cannot send the WKA port open request, don't
rely on the subsequent wait_event condition to immediately let this case
pass without blocking. Also don't want to rely on the additional condition
handling the refcount to be skipped just to finally return with -EIO.
Link: https://lore.kernel.org/r/20220729162529.1620730-1-maier@linux.ibm.com Fixes: 5ab944f97e09 ("[SCSI] zfcp: attach and release SAN nameserver port on demand") Cc: <stable@vger.kernel.org> #v2.6.28+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In nf_tables_updtable, if nf_tables_table_enable returns an error,
nft_trans_destroy is called to free the transaction object.
nft_trans_destroy() calls list_del(), but the transaction was never
placed on a list -- the list head is all zeroes, this results in
a null dereference:
BUG: KASAN: null-ptr-deref in nft_trans_destroy+0x26/0x59
Call Trace:
nft_trans_destroy+0x26/0x59
nf_tables_newtable+0x4bc/0x9bc
[..]
Its sane to assume that nft_trans_destroy() can be called
on the transaction object returned by nft_trans_alloc(), so
make sure the list head is initialised.
Fixes: 55dd6f93076b ("netfilter: nf_tables: use new transaction infrastructure to handle table") Reported-by: mingi cho <mgcho.minic@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Usb core introduce the mechanism of giveback of URB in tasklet context to
reduce hardware interrupt handling time. On some test situation(such as
FIO with 4KB block size), when tasklet callback function called to
giveback URB, interrupt handler add URB node to the bh->head list also.
If check bh->head list again after finish all URB giveback of local_list,
then it may introduce a "dynamic balance" between giveback URB and add URB
to bh->head list. This tasklet callback function may not exit for a long
time, which will cause other tasklet function calls to be delayed. Some
real-time applications(such as KB and Mouse) will see noticeable lag.
In order to prevent the tasklet function from occupying the cpu for a long
time at a time, new URBS will not be added to the local_list even though
the bh->head list is not empty. But also need to ensure the left URB
giveback to be processed in time, so add a member high_prio for structure
giveback_urb_bh to prioritize tasklet and schelule this tasklet again if
bh->head list is not empty.
At the same time, we are able to prioritize tasklet through structure
member high_prio. So, replace the local high_prio_bh variable with this
structure member in usb_hcd_giveback_urb.
Fixes: 94dfd7edfd5c ("USB: HCD: support giveback of URB in tasklet context") Cc: stable <stable@kernel.org> Reviewed-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Weitao Wang <WeitaoWang-oc@zhaoxin.com> Link: https://lore.kernel.org/r/20220726074918.5114-1-WeitaoWang-oc@zhaoxin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When CONFIG_CPUMASK_OFFSTACK and CONFIG_DEBUG_PER_CPU_MAPS is selected,
cpu_max_bits_warn() generates a runtime warning similar as below while
we show /proc/cpuinfo. Fix this by using nr_cpu_ids (the runtime limit)
instead of NR_CPUS to iterate CPUs.
On a bare-metal Power8 system that doesn't have an "ibm,power-rng", a
malicious QEMU and guest that ignore the absence of the
KVM_CAP_PPC_HWRNG flag, and calls H_RANDOM anyway, will dereference a
NULL pointer.
In practice all Power8 machines have an "ibm,power-rng", but let's not
rely on that, add a NULL check and early return in
powernv_get_random_real_mode().
Fixes: e928e9cb3601 ("KVM: PPC: Book3S HV: Add fast real-mode H_RANDOM implementation.") Cc: stable@vger.kernel.org # v4.1+ Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220727143219.2684192-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
By default old pre-3.0 Freescale PCIe controllers reports invalid PCI Class
Code 0x0b20 for PCIe Root Port. It can be seen by lspci -b output on P2020
board which has this pre-3.0 controller:
$ lspci -bvnn
00:00.0 Power PC [0b20]: Freescale Semiconductor Inc P2020E [1957:0070] (rev 21)
!!! Invalid class 0b20 for header type 01
Capabilities: [4c] Express Root Port (Slot-), MSI 00
Fix this issue by programming correct PCI Class Code 0x0604 for PCIe Root
Port to the Freescale specific PCIe register 0x474.
Fix activated by U-Boot stay active also after booting Linux kernel.
But boards which use older U-Boot version without that fix are affected and
still require this fix.
So implement this class code fix also in kernel fsl_pci.c driver.
test_bit(), as any other bitmap op, takes `unsigned long *` as a
second argument (pointer to the actual bitmap), as any bitmap
itself is an array of unsigned longs. However, the ia64_get_irr()
code passes a ref to `u64` as a second argument.
This works with the ia64 bitops implementation due to that they
have `void *` as the second argument and then cast it later on.
This works with the bitmap API itself due to that `unsigned long`
has the same size on ia64 as `u64` (`unsigned long long`), but
from the compiler PoV those two are different.
Define @irr as `unsigned long` to fix that. That implies no
functional changes. Has been hidden for 16 years!
There's a KASAN warning in raid10_remove_disk when running the lvm
test lvconvert-raid-reshape.sh. We fix this warning by verifying that the
value "number" is valid.
BUG: KASAN: slab-out-of-bounds in raid10_remove_disk+0x61/0x2a0 [raid10]
Read of size 8 at addr ffff889108f3d300 by task mdX_raid10/124682
Last potentially related work creation:
kasan_save_stack+0x1e/0x40
__kasan_record_aux_stack+0x9e/0xc0
kvfree_call_rcu+0x84/0x480
timerfd_release+0x82/0x140
L __fput+0xfa/0x400
task_work_run+0x80/0xc0
exit_to_user_mode_prepare+0x155/0x160
syscall_exit_to_user_mode+0x12/0x40
do_syscall_64+0x42/0xc0
entry_SYSCALL_64_after_hwframe+0x46/0xb0
Second to last potentially related work creation:
kasan_save_stack+0x1e/0x40
__kasan_record_aux_stack+0x9e/0xc0
kvfree_call_rcu+0x84/0x480
timerfd_release+0x82/0x140
__fput+0xfa/0x400
task_work_run+0x80/0xc0
exit_to_user_mode_prepare+0x155/0x160
syscall_exit_to_user_mode+0x12/0x40
do_syscall_64+0x42/0xc0
entry_SYSCALL_64_after_hwframe+0x46/0xb0
The buggy address belongs to the object at ffff889108f3d200
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 0 bytes to the right of
256-byte region [ffff889108f3d200, ffff889108f3d300)
Memory state around the buggy address: ffff889108f3d200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff889108f3d280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff889108f3d300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^ ffff889108f3d380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff889108f3d400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit aaac3ba95e4c ("bpf: charge user for creation of BPF maps and
programs") made a wrong assumption of charging against prog->pages.
Unlike map->pages, prog->pages are still subject to change when we
need to expand the program through bpf_prog_realloc().
This can for example happen during verification stage when we need to
expand and rewrite parts of the program. Should the required space
cross a page boundary, then prog->pages is not the same anymore as
its original value that we used to bpf_prog_charge_memlock() on. Thus,
we'll hit a wrap-around during bpf_prog_uncharge_memlock() when prog
is freed eventually. I noticed this that despite having unlimited
memlock, programs suddenly refused to load with EPERM error due to
insufficient memlock.
There are two ways to fix this issue. One would be to add a cached
variable to struct bpf_prog that takes a snapshot of prog->pages at the
time of charging. The other approach is to also account for resizes. I
chose to go with the latter for a couple of reasons: i) We want accounting
rather to be more accurate instead of further fooling limits, ii) adding
yet another page counter on struct bpf_prog would also be a waste just
for this purpose. We also do want to charge as early as possible to
avoid going into the verifier just to find out later on that we crossed
limits. The only place that needs to be fixed is bpf_prog_realloc(),
since only here we expand the program, so we try to account for the
needed delta and should we fail, call-sites check for outcome anyway.
On cBPF to eBPF migrations, we don't grab a reference to the user as
they are charged differently. With that in place, my test case worked
fine.
Fixes: aaac3ba95e4c ("bpf: charge user for creation of BPF maps and programs") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
[Quentin: backport to 4.9: Adjust context in bpf.h ] Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the output of /proc/iomem to show the real hardware device name
including the pa_pathname, e.g. "Merlin 160 Core Centronics [8:16:0]".
Up to now only the pa_pathname ("[8:16.0]") was shown.
usbnet uses the work usbnet_deferred_kevent() to perform tasks which may
sleep. On disconnect, completion of the work was originally awaited in
->ndo_stop(). But in 2003, that was moved to ->disconnect() by historic
commit "[PATCH] USB: usbnet, prevent exotic rtnl deadlock":
The change was made because back then, the kernel's workqueue
implementation did not allow waiting for a single work. One had to wait
for completion of *all* work by calling flush_scheduled_work(), and that
could deadlock when waiting for usbnet_deferred_kevent() with rtnl_mutex
held in ->ndo_stop().
The commit solved one problem but created another: It causes a
use-after-free in USB Ethernet drivers aqc111.c, asix_devices.c,
ax88179_178a.c, ch9200.c and smsc75xx.c:
* If the drivers receive a link change interrupt immediately before
disconnect, they raise EVENT_LINK_RESET in their (non-sleepable)
->status() callback and schedule usbnet_deferred_kevent().
* usbnet_deferred_kevent() invokes the driver's ->link_reset() callback,
which calls netif_carrier_{on,off}().
* That in turn schedules the work linkwatch_event().
Because usbnet_deferred_kevent() is awaited after unregister_netdev(),
netif_carrier_{on,off}() may operate on an unregistered netdev and
linkwatch_event() may run after free_netdev(), causing a use-after-free.
In 2010, usbnet was changed to only wait for a single instance of
usbnet_deferred_kevent() instead of *all* work by commit 23f333a2bfaf
("drivers/net: don't use flush_scheduled_work()").
Unfortunately the commit neglected to move the wait back to
->ndo_stop(). Rectify that omission at long last.
projects / linux-stable / log