While the CSV3 field of the ID_AA64_PFR0 CPU ID register can be checked
to see if a CPU is susceptible to Meltdown and therefore requires kpti
to be enabled, existing CPUs do not implement this field.
We therefore whitelist all unaffected Cortex-A CPUs that do not implement
the CSV3 field.
Commmit eab09532d400 ("binfmt_elf: use ELF_ET_DYN_BASE only for PIE"),
made changes in the rare case when the ELF loader was directly invoked
(e.g to set a non-inheritable LD_LIBRARY_PATH, testing new versions of
the loader), by moving into the mmap region to avoid both ET_EXEC and
PIE binaries. This had the effect of also moving the brk region into
mmap, which could lead to the stack and brk being arbitrarily close to
each other. An unlucky process wouldn't get its requested stack size
and stack allocations could end up scribbling on the heap.
This is illustrated here. In the case of using the loader directly, brk
(so helpfully identified as "[heap]") is allocated with the _loader_ not
the binary. For example, with ASLR entirely disabled, you can see this
more clearly:
The solution is to move brk out of mmap and into ELF_ET_DYN_BASE since
nothing is there in the direct loader case (and ET_EXEC is still far
away at 0x400000). Anything that ran before should still work (i.e.
the ultimately-launched binary already had the brk very far from its
text, so this should be no different from a COMPAT_BRK standpoint). The
only risk I see here is that if someone started to suddenly depend on
the entire memory space lower than the mmap region being available when
launching binaries via a direct loader execs which seems highly
unlikely, I'd hope: this would mean a binary would _not_ work when
exec()ed normally.
(Note that this is only done under CONFIG_ARCH_HAS_ELF_RANDOMIZATION
when randomization is turned on.)
Link: http://lkml.kernel.org/r/20190422225727.GA21011@beast Link: https://lkml.kernel.org/r/CAGXu5jJ5sj3emOT2QPxQkNQk0qbU6zEfu9=Omfhx_p0nCKPSjA@mail.gmail.com Fixes: eab09532d400 ("binfmt_elf: use ELF_ET_DYN_BASE only for PIE") Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Ali Saidi <alisaidi@amazon.com> Cc: Ali Saidi <alisaidi@amazon.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Frank van der Linden <fllinden@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Once upon a time, commit 2cac0c00a6cd ("ovl: get exclusive ownership on
upper/work dirs") in v4.13 added some sanity checks on overlayfs layers.
This change caused a docker regression. The root cause was mount leaks
by docker, which as far as I know, still exist.
To mitigate the regression, commit 85fdee1eef1a ("ovl: fix regression
caused by exclusive upper/work dir protection") in v4.14 turned the
mount errors into warnings for the default index=off configuration.
Recently, commit 146d62e5a586 ("ovl: detect overlapping layers") in
v5.2, re-introduced exclusive upper/work dir checks regardless of
index=off configuration.
This changes the status quo and mount leak related bug reports have
started to re-surface. Restore the status quo to fix the regressions.
To clarify, index=off does NOT relax overlapping layers check for this
ovelayfs mount. index=off only relaxes exclusive upper/work dir checks
with another overlayfs mount.
To cover the part of overlapping layers detection that used the
exclusive upper/work dir checks to detect overlap with self upper/work
dir, add a trap also on the work base dir.
The PCI kirin driver compilation produces the following section mismatch
warning:
WARNING: vmlinux.o(.text+0x4758cc): Section mismatch in reference from
the function kirin_pcie_probe() to the function
.init.text:kirin_add_pcie_port()
The function kirin_pcie_probe() references
the function __init kirin_add_pcie_port().
This is often because kirin_pcie_probe lacks a __init
annotation or the annotation of kirin_add_pcie_port is wrong.
Remove '__init' from kirin_add_pcie_port() to fix it.
After the conversion to lock-less dma-api call the
increase_address_space() function can be called without any
locking. Multiple CPUs could potentially race for increasing
the address space, leading to invalid domain->mode settings
and invalid page-tables. This has been happening in the wild
under high IO load and memory pressure.
Fix the race by locking this operation. The function is
called infrequently so that this does not introduce
a performance regression in the dma-api path again.
Reported-by: Qian Cai <cai@lca.pw> Fixes: 256e4621c21a ('iommu/amd: Make use of the generic IOVA allocator') Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
When devices are attached to the amd_iommu in a kdump kernel, the old device
table entries (DTEs), which were copied from the crashed kernel, will be
overwritten with a new domain number. When the new DTE is written, the IOMMU
is told to flush the DTE from its internal cache--but it is not told to flush
the translation cache entries for the old domain number.
Without this patch, AMD systems using the tg3 network driver fail when kdump
tries to save the vmcore to a network system, showing network timeouts and
(sometimes) IOMMU errors in the kernel log.
This patch will flush IOMMU translation cache entries for the old domain when
a DTE gets overwritten with a new domain number.
Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com> Fixes: 3ac3e5ee5ed5 ('iommu/amd: Copy old trans table from old kernel') Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
If a request_key authentication token key gets revoked, there's a window in
which request_key_auth_describe() can see it with a NULL payload - but it
makes no check for this and something like the following oops may occur:
When the 'start' parameter is >= 0xFF000000 on 32-bit
systems, or >= 0xFFFFFFFF'FF000000 on 64-bit systems,
fill_gva_list() gets into an infinite loop.
With such inputs, 'cur' overflows after adding HV_TLB_FLUSH_UNIT
and always compares as less than end. Memory is filled with
guest virtual addresses until the system crashes.
Fix this by never incrementing 'cur' to be larger than 'end'.
Reported-by: Jong Hyun Park <park.jonghyun@yonsei.ac.kr> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 2ffd9e33ce4a ("x86/hyper-v: Use hypercall for remote TLB flush") Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Identical to __put_user(); the __get_user() argument evalution will too
leak UBSAN crud into the __uaccess_begin() / __uaccess_end() region.
While uncommon this was observed to happen for:
drivers/xen/gntdev.c: if (__get_user(old_status, batch->status[i]))
where UBSAN added array bound checking.
This complements commit:
6ae865615fc4 ("x86/uaccess: Dont leak the AC flag into __put_user() argument evaluation")
If devm_request_irq() fails to disable all interrupts, no cleanup is
performed before retuning the error. To fix this issue, invoke
omap_dma_free() to do the cleanup.
In ti_dra7_xbar_probe(), 'rsv_events' is allocated through kcalloc(). Then
of_property_read_u32_array() is invoked to search for the property.
However, if this process fails, 'rsv_events' is not deallocated, leading to
a memory leak bug. To fix this issue, free 'rsv_events' before returning
the error.
In commit 99cd149efe82 ("sgiseeq: replace use of dma_cache_wback_inv"),
a call to 'get_zeroed_page()' has been turned into a call to
'dma_alloc_coherent()'. Only the remove function has been updated to turn
the corresponding 'free_page()' into 'dma_free_attrs()'.
The error hndling path of the probe function has not been updated.
Fix it now.
Rename the corresponding label to something more in line.
Fixes: 99cd149efe82 ("sgiseeq: replace use of dma_cache_wback_inv") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Thomas Bogendoerfer <tbogendoerfer@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
On embedded environments with hard memory limits it is a normal although
rare case when skb can't be allocated on rx part under high traffic.
In such OOM cases napi_complete_done() was not called.
So the napi object became in an invalid state like it is "scheduled".
Kernel do not re-schedules the poll of that napi object.
Consequently, kernel can not remove that object the system hangs on
`ifconfig down` waiting for a poll.
We are fixing this by gracefully closing napi poll routine with correct
invocation of napi_complete_done.
This was reproduced with artificially failing the allocation of skb to
simulate an "out of memory" error case and check that traffic does
not get stuck.
Fixes: 970a2e9864b0 ("net: ethernet: aquantia: Vector operations") Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com> Signed-off-by: Dmitry Bogdanov <dmitry.bogdanov@aquantia.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
turbostat could be terminated by general protection fault on some latest
hardwares which (for example) support 9 levels of C-states and show 18
"tADDED" lines. That bloats the total output and finally causes buffer
overrun. So let's extend the buffer to avoid this.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
The -w argument in x86_energy_perf_policy currently triggers an
unconditional segfault.
This is because the argument string reads: "+a:c:dD:E:e:f:m:M:rt:u:vw" and
yet the argument handler expects an argument.
When parse_optarg_string is called with a null argument, we then proceed to
crash in strncmp, not horribly friendly.
The man page describes -w as taking an argument, the long form
(--hwp-window) is correctly marked as taking a required argument, and the
code expects it.
As such, this patch simply marks the short form (-w) as requiring an
argument.
Signed-off-by: Zephaniah E. Loss-Cutler-Hull <zephaniah@gmail.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
x86_energy_perf_policy first uses __get_cpuid() to check the maximum
CPUID level and exits if it is too low. It then assumes that later
calls will succeed (which I think is architecturally guaranteed). It
also assumes that CPUID works at all (which is not guaranteed on
x86_32).
If optimisations are enabled, gcc warns about potentially
uninitialized variables. Fix this by adding an exit-on-error after
every call to __get_cpuid() instead of just checking the maximum
level.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
When counting dispatched micro-ops with cnt_ctl=1, in order to prevent
sample bias, IBS hardware preloads the least significant 7 bits of
current count (IbsOpCurCnt) with random values, such that, after the
interrupt is handled and counting resumes, the next sample taken
will be slightly perturbed.
The current count bitfield is in the IBS execution control h/w register,
alongside the maximum count field.
Currently, the IBS driver writes that register with the maximum count,
leaving zeroes to fill the current count field, thereby overwriting
the random bits the hardware preloaded for itself.
Fix the driver to actually retain and carry those random bits from the
read of the IBS control register, through to its write, instead of
overwriting the lower current count bits with zeroes.
Tested with:
perf record -c 100001 -e ibs_op/cnt_ctl=1/pp -a -C 0 taskset -c 0 <workload>
Machines prior to family 10h Rev. C don't have the RDWROPCNT capability,
and have the IbsOpCurCnt bitfield reserved, so this patch shouldn't
affect their operation.
It is unknown why commit db98c5faf8cb ("perf/x86: Implement 64-bit
counter support for IBS") ignored the lower 4 bits of the IbsOpCurCnt
field; the number of preloaded random bits has always been 7, AFAICT.
Signed-off-by: Kim Phillips <kim.phillips@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "Arnaldo Carvalho de Melo" <acme@kernel.org> Cc: <x86@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "Borislav Petkov" <bp@alien8.de> Cc: Stephane Eranian <eranian@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: "Namhyung Kim" <namhyung@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Link: https://lkml.kernel.org/r/20190826195730.30614-1-kim.phillips@amd.com Signed-off-by: Sasha Levin <sashal@kernel.org>
Make sure interrupt handler i2c_dw_irq_handler_slave() has finished
before clearing the the dev->slave pointer in i2c_dw_unreg_slave().
There is possibility for a race if i2c_dw_irq_handler_slave() is running
on another CPU while clearing the dev->slave pointer.
Reported-by: Krzysztof Adamski <krzysztof.adamski@nokia.com> Reported-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
A similar workaround for the suspend/resume problem is needed for yet
another ASUS machines, P6X models. Like the previous fix, the BIOS
doesn't provide the standard DMI_SYS_* entry, so again DMI_BOARD_*
entries are used instead.
Reported-and-tested-by: SteveM <swm@swm1.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
Currently, the ibmvnic driver will not schedule device resets
if the device is being removed, but does not check the device
state before the reset is actually processed. This leads to a race
where a reset is scheduled with a valid device state but is
processed after the driver has been removed, resulting in an oops.
Fix this by checking the device state before processing a queued
reset event.
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Tested-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
pfn_valid can be wrong when parsing a invalid pfn whose phys address
exceeds BITS_PER_LONG as the MSB will be trimed when shifted.
The issue originally arise from bellowing call stack, which corresponding to
an access of the /proc/kpageflags from userspace with a invalid pfn parameter
and leads to kernel panic.
[46886.723249] c7 [<c031ff98>] (stable_page_flags) from [<c03203f8>]
[46886.723264] c7 [<c0320368>] (kpageflags_read) from [<c0312030>]
[46886.723280] c7 [<c0311fb0>] (proc_reg_read) from [<c02a6e6c>]
[46886.723290] c7 [<c02a6e24>] (__vfs_read) from [<c02a7018>]
[46886.723301] c7 [<c02a6f74>] (vfs_read) from [<c02a778c>]
[46886.723315] c7 [<c02a770c>] (SyS_pread64) from [<c0108620>]
(ret_fast_syscall+0x0/0x28)
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
The Falcon microcontroller that runs the XUSB firmware and which is
responsible for exposing the XHCI interface can address only 40 bits of
memory. Typically that's not a problem because Tegra devices don't have
enough system memory to exceed those 40 bits.
However, if the ARM SMMU is enable on Tegra186 and later, the addresses
passed to the XUSB controller can be anywhere in the 48-bit IOV address
space of the ARM SMMU. Since the DMA/IOMMU API starts allocating from
the top of the IOVA space, the Falcon microcontroller is not able to
load the firmware successfully.
Fix this by setting the DMA mask to 40 bits, which will force the DMA
API to map the buffer for the firmware to an IOVA that is addressable by
the Falcon.
It's safer to zero out the password so that it can never be disclosed.
Fixes: 0c219f5799c7 ("cifs: set domainName when a domain-key is used in multiuser") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
When we use a domain-key to authenticate using multiuser we must also set
the domainnmame for the new volume as it will be used and passed to the server
in the NTLMSSP Domain-name.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Looking at the implementation of get_symbol_pos(), it returns the
lowest index for aliasing symbols. In this case, it return 0.
But kallsyms_lookup_size_offset() considers 0 as a failure, which
is obviously wrong (there is definitely a valid symbol living there).
In turn, the kprobe blacklisting stops abruptly, hence the original
error.
A CONFIG_KALLSYMS_ALL kernel wouldn't fail as there is always
some random symbols at the beginning of this array, which are never
looked up via kallsyms_lookup_size_offset.
Fix it by considering that get_symbol_pos() is always successful
(which is consistent with the other uses of this function).
Fixes: ffc5089196446 ("[PATCH] Create kallsyms_lookup_size_offset()") Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
The find_pattern() debug output was printing the 'skip' character.
This can be a NULL-byte and messes up further pr_debug() output.
Output without the fix:
kernel: nf_conntrack_ftp: Pattern matches!
kernel: nf_conntrack_ftp: Skipped up to `<7>nf_conntrack_ftp: find_pattern `PORT': dlen = 8
kernel: nf_conntrack_ftp: find_pattern `EPRT': dlen = 8
Output with the fix:
kernel: nf_conntrack_ftp: Pattern matches!
kernel: nf_conntrack_ftp: Skipped up to 0x0 delimiter!
kernel: nf_conntrack_ftp: Match succeeded!
kernel: nf_conntrack_ftp: conntrack_ftp: match `172,17,0,100,200,207' (20 bytes at 4150681645)
kernel: nf_conntrack_ftp: find_pattern `PORT': dlen = 8
Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Simplify the check in physdev_mt_check() to emit an error message
only when passed an invalid chain (ie, NF_INET_LOCAL_OUT).
This avoids cluttering up the log with errors against valid rules.
For large/heavily modified rulesets, current behavior can quickly
overwhelm the ring buffer, because this function gets called on
every change, regardless of the rule that was changed.
Rahul Tanwar reported the following bug on DT systems:
> 'ioapic_dynirq_base' contains the virtual IRQ base number. Presently, it is
> updated to the end of hardware IRQ numbers but this is done only when IOAPIC
> configuration type is IOAPIC_DOMAIN_LEGACY or IOAPIC_DOMAIN_STRICT. There is
> a third type IOAPIC_DOMAIN_DYNAMIC which applies when IOAPIC configuration
> comes from devicetree.
>
> See dtb_add_ioapic() in arch/x86/kernel/devicetree.c
>
> In case of IOAPIC_DOMAIN_DYNAMIC (DT/OF based system), 'ioapic_dynirq_base'
> remains to zero initialized value. This means that for OF based systems,
> virtual IRQ base will get set to zero.
Such systems will very likely not even boot.
For DT enabled machines ioapic_dynirq_base is irrelevant and not
updated, so simply map the IRQ base 1:1 instead.
get_registers() blindly copies the memory written to by the
usb_control_msg() call even if the underlying urb failed.
This could lead to junk register values being read by the driver, since
some indirect callers of get_registers() ignore the return values. One
example is:
ocp_read_dword() ignores the return value of generic_ocp_read(), which
calls get_registers().
So, emulate PCI "Master Abort" behavior by setting the buffer to all
0xFFs when usb_control_msg() fails.
This patch is copied from the r8152 driver (v2.12.0) published by
Realtek (www.realtek.com).
Signed-off-by: Prashant Malani <pmalani@chromium.org> Acked-by: Hayes Wang <hayeswang@realtek.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
This is because on big-endian machines casts from __u32 to __u16 are
generated by referencing the respective variable as __u16 with an offset
of 2 (as opposed to 0 on little-endian machines).
The verifier already has all the infrastructure in place to allow such
accesses, it's just that they are not explicitly enabled for
eth_protocol field. Enable them for eth_protocol field by using
bpf_ctx_range instead of offsetof.
Ditto for ip_protocol, bind_inany and len, since they already allow
narrowing, and the same problem can arise when working with them.
Multiple batadv_ogm2_packet can be stored in an skbuff. The functions
batadv_v_ogm_send_to_if() uses batadv_v_ogm_aggr_packet() to check if there
is another additional batadv_ogm2_packet in the skb or not before they
continue processing the packet.
The length for such an OGM2 is BATADV_OGM2_HLEN +
batadv_ogm2_packet->tvlv_len. The check must first check that at least
BATADV_OGM2_HLEN bytes are available before it accesses tvlv_len (which is
part of the header. Otherwise it might try read outside of the currently
available skbuff to get the content of tvlv_len.
Fixes: 9323158ef9f4 ("batman-adv: OGMv2 - implement originators logic") Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
A timing hazard exists when an early fork/exec thread begins
exiting and sets its mm pointer to NULL while a separate core
tries to update the section information.
This commit ensures that the mm pointer is not NULL before
setting its section parameters. The arguments provided by
commit 11ce4b33aedc ("ARM: 8672/1: mm: remove tasklist locking
from update_sections_early()") are equally valid for not
requiring grabbing the task_lock around this check.
Fixes: 08925c2f124f ("ARM: 8464/1: Update all mm structures with section adjustments") Signed-off-by: Doug Berger <opendmb@gmail.com> Acked-by: Laura Abbott <labbott@redhat.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Rob Herring <robh@kernel.org> Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org> Cc: Peng Fan <peng.fan@nxp.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
If qed_mcp_send_drv_version() fails, no cleanup is executed, leading to
memory leaks. To fix this issue, introduce the label 'err4' to perform the
cleanup work before returning the error.
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu> Acked-by: Sudarsana Reddy Kalluru <skalluru@marvell.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
Initialise the result count to 0 rather than initialising it to the
argument count. The reason is that we want to ensure we record the
I/O stats correctly in the case where an error is returned (for
instance in the layoutstats).
Currently, we are translating RPC level errors such as timeouts,
as well as interrupts etc into EOPENSTALE, which forces a single
replay of the open attempt. What we actually want to do is
force the replay only in the cases where the returned error
indicates that the file may have changed on the server.
So the fix is to spell out the exact set of errors where we want
to return EOPENSTALE.
Trying to append nfacct related rules results in an unhelpful message.
Although it is suggested to look for more information in dmesg, nothing
can be found there.
# iptables -A <chain> -m nfacct --nfacct-name <acct-object>
iptables: Invalid argument. Run `dmesg' for more information.
This patch fixes the memory misalignment by enforcing 8-byte alignment
within the struct's first revision. This solution is often used in many
other uapi netfilter headers.
Currently the driver does not handle EPROBE_DEFER for the confd gpio.
Use devm_gpiod_get_optional() instead of devm_gpiod_get() and return
error codes from altera_ps_probe().
Fixes: 5692fae0742d ("fpga manager: Add altera-ps-spi driver for Altera FPGAs") Signed-off-by: Phil Reid <preid@electromag.com.au> Signed-off-by: Moritz Fischer <mdf@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
When showing metadata about a single program by invoking
"bpftool prog show PROG", the file descriptor referring to the program
is not closed before returning from the function. Let's close it.
"bind4 allow specific IP & port" and "bind6 deny specific IP & port"
fail on s390 because of endianness issue: the 4 IP address bytes are
loaded as a word and compared with a constant, but the value of this
constant should be different on big- and little- endian machines, which
is not the case right now.
Use __bpf_constant_ntohl to generate proper value based on machine
endianness.
Fixes: 1d436885b23b ("selftests/bpf: Selftest for sys_bind post-hooks.") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
"p runtime/jit: pass > 32bit index to tail_call" fails when
bpf_jit_enable=1, because the tail call is not executed.
This in turn is because the generated code assumes index is 64-bit,
while it must be 32-bit, and as a result prog array bounds check fails,
while it should pass. Even if bounds check would have passed, the code
that follows uses 64-bit index to compute prog array offset.
Fix by using clrj instead of clgrj for comparing index with array size,
and also by using llgfr for truncating index to 32 bits before using it
to compute prog array offset.
The clocks are not yet parsed and prepared until after a successful
sysc_get_clocks(), so there is no need to unprepare the clocks upon
any failure of any of the prior functions in sysc_probe(). The current
code path would have been a no-op because of the clock validity checks
within sysc_unprepare(), but let's just simplify the cleanup path by
returning the error directly.
While at this, also fix the cleanup path for a sysc_init_resets()
failure which is executed after the clocks are prepared.
Signed-off-by: Suman Anna <s-anna@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Non-serio path of Amstrad Delta FIQ deferred handler depended on
irq_ack() method provided by OMAP GPIO driver. That method has been
removed by commit 693de831c6e5 ("gpio: omap: remove irq_ack method").
Remove useless code from the deferred handler and reimplement the
missing operation inside the base FIQ handler.
Should another dependency - irq_unmask() - be ever removed from the OMAP
GPIO driver, WARN once if missing.
Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
According to the latest am572x[1] and dra74x[2] data manuals, mmc3
default, hs, sdr12 and sdr25 modes use iodelay values given in
MMC3_MANUAL1. Set the MODE_SELECT bit for these so that manual mode is
selected and correct iodelay values can be configured.
We have errata i688 workaround produce warnings on SoCs other than
omap4 and omap5:
omap4_sram_init:Unable to allocate sram needed to handle errata I688
omap4_sram_init:Unable to get sram pool needed to handle errata I688
This is happening because there is no ti,omap4-mpu node, or no SRAM
to configure for the other SoCs, so let's remove the warning based
on the SoC revision checks.
As nobody has complained it seems that the other SoC variants do not
need this workaround.
Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
"masking, test in bounds 3" fails on s390, because
BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0) ignores the top 32 bits of
BPF_REG_2. The reason is that JIT emits lcgfr instead of lcgr.
The associated comment indicates that the code was intended to
emit lcgr in the first place, it's just that the wrong opcode
was used.
TRM says PWMSS_SYSCONFIG bit for SOFTRESET changes to zero when
reset is completed. Let's configure it as otherwise we get warnings
on boot when we check the data against dts provided data. Eventually
the legacy platform data will be just dropped, but let's fix the
warning first.
Reviewed-by: Suman Anna <s-anna@ti.com> Tested-by: Keerthy <j-keerthy@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
If UHS speed modes are enabled, a compatible SD card switches down to
1.8V during enumeration. If after this a software reboot/crash takes
place and on-chip ROM tries to enumerate the SD card, the difference in
IO voltages (host @ 3.3V and card @ 1.8V) may end up damaging the card.
The fix for this is to have support for power cycling the card in
hardware (with a PORz/soft-reset line causing a power cycle of the
card). Because the beaglebone X15 (rev A,B and C), am57xx-idks and
am57xx-evms don't have this capability, disable voltage switching for
these boards.
The major effect of this is that the maximum supported speed
mode is now high speed(50 MHz) down from SDR104(200 MHz).
commit 88a748419b84 ("ARM: dts: am57xx-idk: Remove support for voltage
switching for SD card") did this only for idk boards. Do it for all
affected boards.
Signed-off-by: Faiz Abbas <faiz_abbas@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1222a1601488 ("nl80211: Fix possible Spectre-v1 for CQM
RSSI thresholds") was incomplete and requires one more fix to
prevent accessing to rssi_thresholds[n] because user can control
rssi_thresholds[i] values to make i reach to n. For example,
rssi_thresholds = {-400, -300, -200, -100} when last is -34.
Cc: stable@vger.kernel.org Fixes: 1222a1601488 ("nl80211: Fix possible Spectre-v1 for CQM RSSI thresholds") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Masashi Honma <masashi.honma@gmail.com> Link: https://lore.kernel.org/r/20190908005653.17433-1-masashi.honma@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mwifiex_update_vs_ie(),mwifiex_set_uap_rates() and
mwifiex_set_wmm_params() call memcpy() without checking
the destination size.Since the source is given from
user-space, this may trigger a heap buffer overflow.
Fix them by putting the length check before performing memcpy().
This fix addresses CVE-2019-14814,CVE-2019-14815,CVE-2019-14816.
Signed-off-by: Wen Huang <huangwenabc@gmail.com> Acked-by: Ganapathi Bhat <gbhat@marvell.comg> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When half-duplex RS485 communication is used, after RX is started, TX
tasklet still needs to be scheduled tasklet. This avoids console freezing
when more data is to be transmitted, if the serial communication is not
closed.
Fixes: 69646d7a3689 ("tty/serial: atmel: RS485 HD w/DMA: enable RX after TX is stopped") Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20190813074025.16218-1-razvan.stefanescu@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sequence of arguments which was passed to handle_lsr_errors() didn't
match the parameters defined in that function, &lsr was passed to flag
and &flag was passed to lsr, this patch fixed that.
The VPD implementation from Chromium Vital Product Data project used to
parse data from untrusted input without checking if the meta data is
invalid or corrupted. For example, the size from decoded content may
be negative value, or larger than whole input buffer. Such invalid data
may cause buffer overflow.
To fix that, the size parameters passed to vpd_decode functions should
be changed to unsigned integer (u32) type, and the parsing of entry
header should be refactored so every size field is correctly verified
before starting to decode.
Fixes: ad2ac9d5c5e0 ("firmware: Google VPD: import lib_vpd source files") Signed-off-by: Hung-Te Lin <hungte@chromium.org> Cc: stable <stable@vger.kernel.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20190830022402.214442-1-hungte@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The first/last indexes are typically shared with a user app.
The app can change the 'last' index that the kernel uses
to store the next result. This change sanity checks the index
before using it for writing to a potentially arbitrary address.
This fixes CVE-2019-14821.
Cc: stable@vger.kernel.org Fixes: 5f94c1741bdc ("KVM: Add coalesced MMIO support (common part)") Signed-off-by: Matt Delco <delco@chromium.org> Signed-off-by: Jim Mattson <jmattson@google.com> Reported-by: syzbot+983c866c3dd6efa3662a@syzkaller.appspotmail.com
[Use READ_ONCE. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When skb_shinfo(skb) is not able to cache extra fragment (that is,
skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS), xennet_fill_frags() assumes
the sk_buff_head list is already empty. As a result, cons is increased only
by 1 and returns to error handling path in xennet_poll().
However, if the sk_buff_head list is not empty, queue->rx.rsp_cons may be
set incorrectly. That is, queue->rx.rsp_cons would point to the rx ring
buffer entries whose queue->rx_skbs[i] and queue->grant_rx_ref[i] are
already cleared to NULL. This leads to NULL pointer access in the next
iteration to process rx ring buffer entries.
Below is how xennet_poll() does error handling. All remaining entries in
tmpq are accounted to queue->rx.rsp_cons without assuming how many
outstanding skbs are remained in the list.
985 static int xennet_poll(struct napi_struct *napi, int budget)
... ...
1032 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1033 __skb_queue_head(&tmpq, skb);
1034 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1035 goto err;
1036 }
It is better to always have the error handling in the same way.
Fixes: ad4f15dc2c70 ("xen/netfront: don't bug in case of too many frags") Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
UDP reuseport groups can hold a mix unconnected and connected sockets.
Ensure that connections only receive all traffic to their 4-tuple.
Fast reuseport returns on the first reuseport match on the assumption
that all matches are equal. Only if connections are present, return to
the previous behavior of scoring all sockets.
Record if connections are present and if so (1) treat such connected
sockets as an independent match from the group, (2) only return
2-tuple matches from reuseport and (3) do not return on the first
2-tuple reuseport match to allow for a higher scoring match later.
New field has_conns is set without locks. No other fields in the
bitmap are modified at runtime and the field is only ever set
unconditionally, so an RMW cannot miss a change.
Fixes: e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection") Link: http://lkml.kernel.org/r/CA+FuTSfRP09aJNYRt04SS6qj22ViiOEWaWmLAwX0psk8-PGNxw@mail.gmail.com Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Craig Gallek <kraig@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In ip6erspan_tunnel_xmit(), if the skb will not be sent out, it has to
be freed on the tx_err path. Otherwise when deleting a netns, it would
cause dst/dev to leak, and dmesg shows:
unregister_netdevice: waiting for lo to become free. Usage count = 1
Fixes: ef7baf5e083c ("ip6_gre: add ip6 erspan collect_md mode") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: William Tu <u9012063@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The hardware manual should be revised, but the initial value of
VBCTRL.OCCLREN is set to 1 actually. If the bit is set, the hardware
clears VBCTRL.VBOUT and ADPCTRL.DRVVBUS registers automatically
when the hardware detects over-current signal from a USB power switch.
However, since the hardware doesn't have any registers which
indicates over-current, the driver cannot handle it at all. So, if
"is_otg_channel" hardware detects over-current, since ADPCTRL.DRVVBUS
register is cleared automatically, the channel cannot be used after
that.
To resolve this behavior, this patch sets the VBCTRL.OCCLREN to 0
to keep ADPCTRL.DRVVBUS even if the "is_otg_channel" hardware
detects over-current. (We assume a USB power switch itself protects
over-current and turns the VBUS off.)
This patch is inspired by a BSP patch from Kazuya Mizuguchi.
Fixes: 1114e2d31731 ("phy: rcar-gen3-usb2: change the mode to OTG on the combined channel") Cc: <stable@vger.kernel.org> # v4.5+ Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The error occurs when the descriptors_changed() routine (called during
a device reset) attempts to compare the old and new BOS and capability
descriptors. The length it uses for the comparison is the
wTotalLength value stored in BOS descriptor, but this value is not
necessarily the same as the length actually allocated for the
descriptors. If it is larger the routine will call memcmp() with a
length that is too big, thus reading beyond the end of the allocated
region and leading to this fault.
The kernel reads the BOS descriptor twice: first to get the total
length of all the capability descriptors, and second to read it along
with all those other descriptors. A malicious (or very faulty) device
may send different values for the BOS descriptor fields each time.
The memory area will be allocated using the wTotalLength value read
the first time, but stored within it will be the value read the second
time.
To prevent this possibility from causing any errors, this patch
modifies the BOS descriptor after it has been read the second time:
It sets the wTotalLength field to the actual length of the descriptors
that were read in and validated. Then the memcpy() call, or any other
code using these descriptors, will be able to rely on wTotalLength
being valid.
We use mmu_vmemmap_psize to find the page size for mapping the vmmemap area.
With radix translation, we are suboptimally setting this value to PAGE_SIZE.
We do check for 2M page size support and update mmu_vmemap_psize to use
hugepage size but we suboptimally reset the value to PAGE_SIZE in
radix__early_init_mmu(). This resulted in always mapping vmemmap area with
64K page size.
Fixes: 2bfd65e45e87 ("powerpc/mm/radix: Add radix callbacks for early init routines") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tracking CM_ID resource is performed in two stages: creation of cm_id
and connecting it to the cma_dev. It is needed because rdma-cm protocol
exports two separate user-visible calls rdma_create_id and rdma_accept.
At the time of CM_ID creation, the real owner of that object is unknown
yet and we need to grab task_struct. This task_struct is released or
reassigned in attach phase later on. but call to rdma_destroy_id left
this task_struct unreleased.
Such separation is unique to CM_ID and other restrack objects initialize
in one shot. It means that it is safe to use "res->valid" check to catch
unfinished CM_ID flow and release task_struct for that object.
Fixes: 00313983cda6 ("RDMA/nldev: provide detailed CM_ID information") Reported-by: Artemy Kovalyov <artemyko@mellanox.com> Reviewed-by: Artemy Kovalyov <artemyko@mellanox.com> Reviewed-by: Yossi Itigin <yosefe@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Reviewed-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Cc: Håkon Bugge <haakon.bugge@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the generic code path, HID_DG_CONTACTMAX was previously
only read from the second byte of report 0x23.
Another report (0x82) has the HID_DG_CONTACTMAX in the
higher nibble of the third byte. We should support reading the
value of HID_DG_CONTACTMAX no matter what report we are reading
or which position that value is in.
To do this we submit the feature report as a event report
using hid_report_raw_event(). Our modified finger event path
records the value of HID_DG_CONTACTMAX when it sees that usage.
Fixes: 8ffffd5212846 ("HID: wacom: fix timeout on probe for some wacoms") Signed-off-by: Aaron Armstrong Skomra <aaron.skomra@wacom.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
One of the very few warnings I have in the current build comes from
arch/x86/boot/edd.c, where I get the following with a gcc9 build:
arch/x86/boot/edd.c: In function ‘query_edd’:
arch/x86/boot/edd.c:148:11: warning: taking address of packed member of ‘struct boot_params’ may result in an unaligned pointer value [-Waddress-of-packed-member]
148 | mbrptr = boot_params.edd_mbr_sig_buffer;
| ^~~~~~~~~~~
This warning triggers because we throw away all the CFLAGS and then make
a new set for REALMODE_CFLAGS, so the -Wno-address-of-packed-member we
added in the following commit is not present:
The simplest solution for now is to adjust the warning for this version
of CFLAGS as well, but it would definitely make sense to examine whether
REALMODE_CFLAGS could be derived from CFLAGS, so that it picks up changes
in the compiler flags environment automatically.
The compatibility "eeprom" attribute is currently root-only no
matter what the configuration says. The "nvmem" attribute does
respect the setting of the root_only configuration bit, so do the
same for "eeprom".
Signed-off-by: Jean Delvare <jdelvare@suse.de> Fixes: b6c217ab9be6 ("nvmem: Add backwards compatibility support for older EEPROM drivers.") Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20190728184255.563332e6@endymion Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
`dev` (struct rsi_91x_usbdev *) field of adapter
(struct rsi_91x_usbdev *) is allocated and initialized in
`rsi_init_usb_interface`. If any error is detected in information
read from the device side, `rsi_init_usb_interface` will be
freed. However, in the higher level error handling code in
`rsi_probe`, if error is detected, `rsi_91x_deinit` is called
again, in which `dev` will be freed again, resulting double free.
This patch fixes the double free by removing the free operation on
`dev` in `rsi_init_usb_interface`, because `rsi_91x_deinit` is also
used in `rsi_disconnect`, in that code path, the `dev` field is not
(and thus needs to be) freed.
This bug was found in v4.19, but is also present in the latest version
of kernel. Fixes CVE-2019-15504.
The CB4063 board uses pmc_plt_clk* clocks for ethernet controllers. This
adds it to the critclk_systems DMI table so the clocks are marked as
CLK_CRITICAL and not turned off.
Fix the data type as DFSDM raw output is complements 2,
24bits left aligned in a 32-bit register.
This change does not affect AUDIO path
- Set data as signed for IIO (as for AUDIO)
- Set 8 bit right shift for IIO.
The 8 LSBs bits of data contains channel info and are masked.
This commit has caused regressions in notebooks that support suspend
to idle such as the XPS 9360, XPS 9370 and XPS 9380.
These notebooks will wakeup from suspend to idle from an unsolicited
advertising packet from an unpaired BLE device.
In a bug report it was sugggested that this is caused by a generic
lack of LE privacy support. Revert this commit until that behavior
can be avoided by the kernel.
Each iteration of for_each_child_of_node puts the previous
node, but in the case of a goto from the middle of the loop, there is
no put, thus causing a memory leak. Hence add an of_node_put before the
goto in two places.
Issue found with Coccinelle.
Fixes: 119f5173628a (drm/mediatek: Add DRM Driver for Mediatek SoC MT8173) Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com> Signed-off-by: CK Hu <ck.hu@mediatek.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newer GPD MicroPC BIOS versions have proper DMI strings, add an extra quirk
table entry for these new strings. This is good news, as this means that we
no longer have to update the BIOS dates list with every BIOS update.
TI-SCI firmware will only respond to messages when the
TI_SCI_FLAG_REQ_ACK_ON_PROCESSED flag is set. Most messages already do
this, set this for the ones that do not.
This will be enforced in future firmware that better match the TI-SCI
specifications, this patch will not break users of existing firmware.
Fixes: aa276781a64a ("firmware: Add basic support for TI System Control Interface (TI-SCI) protocol") Signed-off-by: Andrew F. Davis <afd@ti.com> Acked-by: Nishanth Menon <nm@ti.com> Tested-by: Alejandro Hernandez <ajhernandez@ti.com> Signed-off-by: Tero Kristo <t-kristo@ti.com> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For decrypt, req->cryptlen includes the size of the authentication
part while all functions of the driver expect cryptlen to be
the size of the encrypted data.
As it is not expected to change req->cryptlen, this patch
implements local calculation of cryptlen.
When data size is not a multiple of the alg's block size,
the SEC generates an error interrupt and dumps the registers.
And for NULL size, the SEC does just nothing and the interrupt
is awaited forever.
This patch ensures the data size is correct before submitting
the request to the SEC engine.
Although the HW accepts any size and silently truncates
it to the correct length, the extra tests expects EINVAL
to be returned when the key size is not valid.
// sd is freed
kernfs_new_node(sd)
kernfs_get(glue_dir)
kernfs_add_one()
kernfs_put()
Before CPU1 remove last child device under glue dir, if CPU2 add a new
device under glue dir, the glue_dir kobject reference count will be
increase to 2 via kobject_get() in get_device_parent(). And CPU2 has
been called kernfs_create_dir_ns(), but not call kernfs_new_node().
Meanwhile, CPU1 call sysfs_remove_dir() and sysfs_put(). This result in
glue_dir->sd is freed and it's reference count will be 0. Then CPU2 call
kernfs_get(glue_dir) will trigger a warning in kernfs_get() and increase
it's reference count to 1. Because glue_dir->sd is freed by CPU1, the next
call kernfs_add_one() by CPU2 will fail(This is also use-after-free)
and call kernfs_put() to decrease reference count. Because the reference
count is decremented to 0, it will also call kmem_cache_free() to free
the glue_dir->sd again. This will result in double free.
In order to avoid this happening, we also should make sure that kernfs_node
for glue_dir is released in CPU1 only when refcount for glue_dir kobj is
1 to fix this race.
The following calltrace is captured in kernel 4.14 with the following patch
applied:
commit 726e41097920 ("drivers: core: Remove glue dirs from sysfs earlier")
Commit c877154d307f fixed an uninitialized variable and optimized
the function to not call tnc_next() in the first iteration of the
loop. While this seemed perfectly legit and wise, it turned out to
be illegal.
If the lookup function does not find an exact match it will rewind
the cursor by 1.
The rewinded cursor will not match the name hash we are looking for
and this results in a spurious -ENOENT.
So we need to move to the next entry in case of an non-exact match,
but not if the match was exact.
While we are here, update the documentation to avoid further confusion.
projects / linux-stable / log