Some RX errors, notably when disconnecting the cable, increase the RCSR
register. Once half full (0x7fff), an interrupt flood is generated. I
measured ~3k/s interrupts even after the RX errors transfer was
stopped.
Since we don't read and clear the RCSR register, we should disable this
interrupt.
Fixes: 87461f7a58ab ("net: phy: DP83822 initial driver submission") Signed-off-by: Enguerrand de Ribaucourt <enguerrand.de-ribaucourt@savoirfairelinux.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm: Fix TLB flush for not-first PFNMAP mappings in unmap_region()
This is a stable-specific patch.
I botched the stable-specific rewrite of
commit b67fbebd4cf98 ("mmu_gather: Force tlb-flush VM_PFNMAP vmas"):
As Hugh pointed out, unmap_region() actually operates on a list of VMAs,
and the variable "vma" merely points to the first VMA in that list.
So if we want to check whether any of the VMAs we're operating on is
PFNMAP or MIXEDMAP, we have to iterate through the list and check each VMA.
USB external storage device(0x0b05:1932), use gnome-disk-utility tools
to test usb write < 30MB/s.
if does not to load module of uas for this device, can increase the
write speed from 20MB/s to >40MB/s.
2 keymap fixes for the Acer Aspire One AOD270 and the same hardware
rebranded as Packard Bell Dot SC:
1. The F2 key is marked with a big '?' symbol on the Packard Bell Dot SC,
this sends WMID_HOTKEY_EVENTs with a scancode of 0x27 add a mapping
for this.
2. Scancode 0x61 is KEY_SWITCHVIDEOMODE. Usually this is a duplicate
input event with the "Video Bus" input device events. But on these devices
the "Video Bus" does not send events for this key. Map 0x61 to KEY_UNKNOWN
instead of using KE_IGNORE so that udev/hwdb can override it on these devs.
The MSI is probably raised by incoming packets, so power down the device
and disable bus mastering to stop the traffic, as user confirmed this
approach works.
In addition to that, be extra safe and cancel reset task if it's running.
If the previous thing cat'ing $debugfs/rd left the FIFO full, then
subsequent open could deadlock in rd_write() (because open is blocked,
not giving a chance for read() to consume any data in the FIFO). Also
it is generally a good idea to clear out old data from the FIFO.
Prior to Linux 5.3, ->transport_lock in sunrpc required the _bh style
spinlocks (when not called from a bottom-half handler).
When upstream 3848e96edf4788f772d83990022fa7023a233d83 was backported to
stable kernels, the spin_lock/unlock calls should have been changed to
the _bh version, but this wasn't noted in the patch and didn't happen.
So convert these lock/unlock calls to the _bh versions.
This patch is required for any stable kernel prior to 5.3 to which the
above mentioned patch was backported. Namely 4.9.y, 4.14.y, 4.19.y.
The Qualcomm dwc3 runtime-PM implementation checks the xhci
platform-device pointer in the wakeup-interrupt handler to determine
whether the controller is in host mode and if so triggers a resume.
After a role switch in OTG mode the xhci platform-device would have been
freed and the next wakeup from runtime suspend would access the freed
memory.
Note that role switching is executed from a freezable workqueue, which
guarantees that the pointer is stable during suspend.
Also note that runtime PM has been broken since commit 2664deb09306
("usb: dwc3: qcom: Honor wakeup enabled/disabled state"), which
incidentally also prevents this issue from being triggered.
At least one older CH341 appears to have the RX timer enable bit
inverted so that setting it disables the RX timer and prevents the FIFO
from emptying until it is full.
Only set the RX timer enable bit for devices with version newer than
0x27 (even though this probably affects all pre-0x30 devices).
Reported-by: Jonathan Woithe <jwoithe@just42.net> Tested-by: Jonathan Woithe <jwoithe@just42.net> Link: https://lore.kernel.org/r/Ys1iPTfiZRWj2gXs@marvin.atrad.com.au Fixes: 4e46c410e050 ("USB: serial: ch341: reinitialize chip on reconfiguration") Cc: stable@vger.kernel.org # 4.10 Signed-off-by: Johan Hovold <johan@kernel.org>
[ johan: backport to 5.4 ] Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Disable LCR updates for pre-0x30 devices which use a different (unknown)
protocol for line control and where the current register write causes
the next received character to be lost.
Note that updating LCR using the INIT command has no effect on these
devices either.
Reported-by: Jonathan Woithe <jwoithe@just42.net> Tested-by: Jonathan Woithe <jwoithe@just42.net> Link: https://lore.kernel.org/r/Ys1iPTfiZRWj2gXs@marvin.atrad.com.au Fixes: 4e46c410e050 ("USB: serial: ch341: reinitialize chip on reconfiguration") Fixes: 55fa15b5987d ("USB: serial: ch341: fix baud rate and line-control handling") Cc: stable@vger.kernel.org # 4.10 Signed-off-by: Johan Hovold <johan@kernel.org>
[ johan: adjust context to 4.19 ] Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cong Wang noticed that the previous fix for sch_sfb accessing the queued
skb after enqueueing it to a child qdisc was incomplete: the SFB enqueue
function was also calling qdisc_qstats_backlog_inc() after enqueue, which
reads the pkt len from the skb cb field. Fix this by also storing the skb
len, and using the stored value to increment the backlog after enqueueing.
Fixes: 9efd23297cca ("sch_sfb: Don't assume the skb is still around after enqueueing to child") Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> Acked-by: Cong Wang <cong.wang@bytedance.com> Link: https://lore.kernel.org/r/20220905192137.965549-1-toke@toke.dk Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Fix a bug reported and analyzed by Nagaraj Arankal, where the handling
of a spurious non-SACK RTO could cause a connection to fail to clear
retrans_stamp, causing a later RTO to very prematurely time out the
connection with ETIMEDOUT.
Here is the buggy scenario, expanding upon Nagaraj Arankal's excellent
report:
(*1) Send one data packet on a non-SACK connection
(*2) Because no ACK packet is received, the packet is retransmitted
and we enter CA_Loss; but this retransmission is spurious.
(*3) The ACK for the original data is received. The transmitted packet
is acknowledged. The TCP timestamp is before the retrans_stamp,
so tcp_may_undo() returns true, and tcp_try_undo_loss() returns
true without changing state to Open (because tcp_is_sack() is
false), and tcp_process_loss() returns without calling
tcp_try_undo_recovery(). Normally after undoing a CA_Loss
episode, tcp_fastretrans_alert() would see that the connection
has returned to CA_Open and fall through and call
tcp_try_to_open(), which would set retrans_stamp to 0. However,
for non-SACK connections we hold the connection in CA_Loss, so do
not fall through to call tcp_try_to_open() and do not set
retrans_stamp to 0. So retrans_stamp is (erroneously) still
non-zero.
At this point the first "retransmission event" has passed and
been recovered from. Any future retransmission is a completely
new "event". However, retrans_stamp is erroneously still
set. (And we are still in CA_Loss, which is correct.)
(*4) After 16 minutes (to correspond with tcp_retries2=15), a new data
packet is sent. Note: No data is transmitted between (*3) and
(*4) and we disabled keep alives.
The socket's timeout SHOULD be calculated from this point in
time, but instead it's calculated from the prior "event" 16
minutes ago (step (*2)).
(*5) Because no ACK packet is received, the packet is retransmitted.
(*6) At the time of the 2nd retransmission, the socket returns
ETIMEDOUT, prematurely, because retrans_stamp is (erroneously)
too far in the past (set at the time of (*2)).
This commit fixes this bug by ensuring that we reuse in
tcp_try_undo_loss() the same careful logic for non-SACK connections
that we have in tcp_try_undo_recovery(). To avoid duplicating logic,
we factor out that logic into a new
tcp_is_non_sack_preventing_reopen() helper and call that helper from
both undo functions.
When accessing Ports Performance Counters Register (PPCNT),
local port must be one if it is Function-Per-Port HCA that
HCA_CAP.num_ports is 1.
The offending patch can change the local port to other values
when accessing PPCNT after enabling switchdev mode. The following
syndrome will be printed:
# cat /sys/class/infiniband/rdmap4s0f0/ports/2/counters/*
# dmesg
mlx5_core 0000:04:00.0: mlx5_cmd_check:756:(pid 12450): ACCESS_REG(0x805) op_mod(0x1) failed, status bad parameter(0x3), syndrome (0x1e5585)
Fix it by setting local port to one for Function-Per-Port HCA.
The SRv6 layer allows defining HMAC data that can later be used to sign IPv6
Segment Routing Headers. This configuration is realised via netlink through
four attributes: SEG6_ATTR_HMACKEYID, SEG6_ATTR_SECRET, SEG6_ATTR_SECRETLEN and
SEG6_ATTR_ALGID. Because the SECRETLEN attribute is decoupled from the actual
length of the SECRET attribute, it is possible to provide invalid combinations
(e.g., secret = "", secretlen = 64). This case is not checked in the code and
with an appropriately crafted netlink message, an out-of-bounds read of up
to 64 bytes (max secret length) can occur past the skb end pointer and into
skb_shared_info:
Breakpoint 1, seg6_genl_sethmac (skb=<optimized out>, info=<optimized out>) at net/ipv6/seg6.c:208
208 memcpy(hinfo->secret, secret, slen);
(gdb) bt
#0 seg6_genl_sethmac (skb=<optimized out>, info=<optimized out>) at net/ipv6/seg6.c:208
#1 0xffffffff81e012e9 in genl_family_rcv_msg_doit (skb=skb@entry=0xffff88800b1f9f00, nlh=nlh@entry=0xffff88800b1b7600,
extack=extack@entry=0xffffc90000ba7af0, ops=ops@entry=0xffffc90000ba7a80, hdrlen=4, net=0xffffffff84237580 <init_net>, family=<optimized out>,
family=<optimized out>) at net/netlink/genetlink.c:731
#2 0xffffffff81e01435 in genl_family_rcv_msg (extack=0xffffc90000ba7af0, nlh=0xffff88800b1b7600, skb=0xffff88800b1f9f00,
family=0xffffffff82fef6c0 <seg6_genl_family>) at net/netlink/genetlink.c:775
#3 genl_rcv_msg (skb=0xffff88800b1f9f00, nlh=0xffff88800b1b7600, extack=0xffffc90000ba7af0) at net/netlink/genetlink.c:792
#4 0xffffffff81dfffc3 in netlink_rcv_skb (skb=skb@entry=0xffff88800b1f9f00, cb=cb@entry=0xffffffff81e01350 <genl_rcv_msg>)
at net/netlink/af_netlink.c:2501
#5 0xffffffff81e00919 in genl_rcv (skb=0xffff88800b1f9f00) at net/netlink/genetlink.c:803
#6 0xffffffff81dff6ae in netlink_unicast_kernel (ssk=0xffff888010eec800, skb=0xffff88800b1f9f00, sk=0xffff888004aed000)
at net/netlink/af_netlink.c:1319
#7 netlink_unicast (ssk=ssk@entry=0xffff888010eec800, skb=skb@entry=0xffff88800b1f9f00, portid=portid@entry=0, nonblock=<optimized out>)
at net/netlink/af_netlink.c:1345
#8 0xffffffff81dff9a4 in netlink_sendmsg (sock=<optimized out>, msg=0xffffc90000ba7e48, len=<optimized out>) at net/netlink/af_netlink.c:1921
...
(gdb) p/x ((struct sk_buff *)0xffff88800b1f9f00)->head + ((struct sk_buff *)0xffff88800b1f9f00)->end
$1 = 0xffff88800b1b76c0
(gdb) p/x secret
$2 = 0xffff88800b1b76c0
(gdb) p slen
$3 = 64 '@'
The OOB data can then be read back from userspace by dumping HMAC state. This
commit fixes this by ensuring SECRETLEN cannot exceed the actual length of
SECRET.
Reported-by: Lucas Leong <wmliang.tw@gmail.com>
Tested: verified that EINVAL is correctly returned when secretlen > len(secret) Fixes: 4f4853dc1c9c1 ("ipv6: sr: implement API to control SR HMAC structure") Signed-off-by: David Lebrun <dlebrun@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
The driver incorrectly frees client instance and subsequent
i40e module removal leads to kernel crash.
Reproducer:
1. Do ethtool offline test followed immediately by another one
host# ethtool -t eth0 offline; ethtool -t eth0 offline
2. Remove recursively irdma module that also removes i40e module
host# modprobe -r irdma
Two offline tests cause IRDMA driver failure (ETIMEDOUT) and this
failure is indicated back to i40e_client_subtask() that calls
i40e_client_del_instance() to free client instance referenced
by pf->cinst and sets this pointer to NULL. During the module
removal i40e_remove() calls i40e_lan_del_device() that dereferences
pf->cinst that is NULL -> crash.
Do not remove client instance when client open callbacks fails and
just clear __I40E_CLIENT_INSTANCE_OPENED bit. The driver also needs
to take care about this situation (when netdev is up and client
is NOT opened) in i40e_notify_client_of_netdev_close() and
calls client close callback only when __I40E_CLIENT_INSTANCE_OPENED
is set.
Fixes: 0ef2d5afb12d ("i40e: KISS the client interface") Signed-off-by: Ivan Vecera <ivecera@redhat.com> Tested-by: Helena Anna Dubel <helena.anna.dubel@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
There is a shift wrapping bug in this code so anything thing above
31 will return false.
Fixes: 35c55c9877f8 ("tipc: add neighbor monitoring framework") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
The sch_sfb enqueue() routine assumes the skb is still alive after it has
been enqueued into a child qdisc, using the data in the skb cb field in the
increment_qlen() routine after enqueue. However, the skb may in fact have
been freed, causing a use-after-free in this case. In particular, this
happens if sch_cake is used as a child of sfb, and the GSO splitting mode
of CAKE is enabled (in which case the skb will be split into segments and
the original skb freed).
Fix this by copying the sfb cb data to the stack before enqueueing the skb,
and using this stack copy in increment_qlen() instead of the skb pointer
itself.
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-18231 Fixes: e13e02a3c68d ("net_sched: SFB flow scheduler") Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
Ensure the match happens in the right direction, previously the
destination used was the server, not the NAT host, as the comment
shows the code intended.
Additionally nf_nat_irc uses port 0 as a signal and there's no valid way
it can appear in a DCC message, so consider port 0 also forged.
The IPv6 path already drops dst in the daddr changed case, but the IPv4
path does not. This change makes the two code paths consistent.
Further, it is possible that there is already a metadata_dst allocated from
ingress that might already be attached to skbuff->dst while following
the bridge path. If it is not released before setting a new
metadata_dst, it will be leaked. This is similar to what is done in
bpf_set_tunnel_key() or ip6_route_input().
It is important to note that the memory being leaked is not the dst
being set in the bridge code, but rather memory allocated from some
other code path that is not being freed correctly before the skb dst is
overwritten.
An example of the leakage fixed by this commit found using kmemleak:
There is a very common pattern of using
debugfs_remove(debufs_lookup(..)) which results in a dentry leak of the
dentry that was looked up. Instead of having to open-code the correct
pattern of calling dput() on the dentry, create
debugfs_lookup_and_remove() to handle this pattern automatically and
properly without any memory leaks.
The system call gate area counts as kernel text but trying
to install a kprobe in this area fails with an Oops later on.
To fix this explicitly disallow the gate area for kprobes.
There may be a bad USB audio device with a USB ID of (0x04fa, 0x4201) and
the number of it's interfaces less than 4, an out-of-bounds read bug occurs
when parsing the interface descriptor for this device.
In loopback_jiffies_timer_pos_update(), we are getting jiffies twice.
First time for playback, second time for capture. Jiffies can be updated
between these two calls and if the capture jiffies is larger, extra zeros
will be filled in the capture buffer.
Change to get jiffies once and use it for both playback and capture.
The voice allocator sometimes begins allocating from near the end of the
array and then wraps around, however snd_emu10k1_pcm_channel_alloc()
accesses the newly allocated voices as if it never wrapped around.
This results in out of bounds access if the first voice has a high enough
index so that first_voice + requested_voice_count > NUM_G (64).
The more voices are requested, the more likely it is for this to occur.
This was initially discovered using PipeWire, however it can be reproduced
by calling aplay multiple times with 16 channels:
aplay -r 48000 -D plughw:CARD=Live,DEV=3 -c 16 /dev/zero
UBSAN: array-index-out-of-bounds in sound/pci/emu10k1/emupcm.c:127:40
index 65 is out of range for type 'snd_emu10k1_voice [64]'
CPU: 1 PID: 31977 Comm: aplay Tainted: G W IOE 6.0.0-rc2-emu10k1+ #7
Hardware name: ASUSTEK COMPUTER INC P5W DH Deluxe/P5W DH Deluxe, BIOS 3002 07/22/2010
Call Trace:
<TASK>
dump_stack_lvl+0x49/0x63
dump_stack+0x10/0x16
ubsan_epilogue+0x9/0x3f
__ubsan_handle_out_of_bounds.cold+0x44/0x49
snd_emu10k1_playback_hw_params+0x3bc/0x420 [snd_emu10k1]
snd_pcm_hw_params+0x29f/0x600 [snd_pcm]
snd_pcm_common_ioctl+0x188/0x1410 [snd_pcm]
? exit_to_user_mode_prepare+0x35/0x170
? do_syscall_64+0x69/0x90
? syscall_exit_to_user_mode+0x26/0x50
? do_syscall_64+0x69/0x90
? exit_to_user_mode_prepare+0x35/0x170
snd_pcm_ioctl+0x27/0x40 [snd_pcm]
__x64_sys_ioctl+0x95/0xd0
do_syscall_64+0x5c/0x90
? do_syscall_64+0x69/0x90
? do_syscall_64+0x69/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Though acpi_find_last_cache_level() always returned signed value and the
document states it will return any errors caused by lack of a PPTT table,
it never returned negative values before.
Commit 0c80f9e165f8 ("ACPI: PPTT: Leave the table mapped for the runtime usage")
however changed it by returning -ENOENT if no PPTT was found. The value
returned from acpi_find_last_cache_level() is then assigned to unsigned
fw_level.
It will result in the number of cache leaves calculated incorrectly as
a huge value which will then cause the following warning from __alloc_pages
as the order would be great than MAX_ORDER because of incorrect and huge
cache leaves value.
If a 32-bit kernel was compiled for PA2.0 CPUs, it won't be able to run
on machines with PA1.x CPUs. Add a check and bail out early if a PA1.x
machine is detected.
Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Zhenneng Li <lizhenneng@kylinos.cn> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
It's been reported that there is a possible data-race accessing to the
global card_requested[] array at ALSA sequencer core, which is used
for determining whether to call request_module() for the card or not.
This data race itself is almost harmless, as it might end up with one
extra request_module() call for the already loaded module at most.
But it's still better to fix.
This patch addresses the possible data race of card_requested[] and
client_requested[] arrays by replacing them with bitmask.
It's an atomic operation and can work without locks.
ALSA OSS sequencer refers to a global variable max_midi_devs at
creating a new port, storing it to its own field. Meanwhile this
variable may be changed by other sequencer events at
snd_seq_oss_midi_check_exit_port() in parallel, which may cause a data
race.
OTOH, this data race itself is almost harmless, as the access to the
MIDI device is done via get_mdev() and it's protected with a refcount,
hence its presence is guaranteed.
Though, it's sill better to address the data-race from the code sanity
POV, and this patch adds the proper spinlock for the protection.
Upon reception, a packet must be categorized, either it's destination is
the host, or it is another host. A packet with no destination addressing
fields may be valid in two situations:
- the packet has no source field: only ACKs are built like that, we
consider the host as the destination.
- the packet has a valid source field: it is directed to the PAN
coordinator, as for know we don't have this information we consider we
are not the PAN coordinator.
There was likely a copy/paste error made during a previous cleanup
because the if clause is now containing exactly the same condition as in
the switch case, which can never be true. In the past the destination
address was used in the switch and the source address was used in the
if, which matches what the spec says.
Cc: stable@vger.kernel.org Fixes: ae531b9475f6 ("ieee802154: use ieee802154_addr instead of *_sa variants") Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220826142954.254853-1-miquel.raynal@bootlin.com Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When we are not connected to a channel, sending channel "switch"
announcement doesn't make any sense.
The BSS list is empty in that case. This causes the for loop in
cfg80211_get_bss() to be bypassed, so the function returns NULL
(check line 1424 of net/wireless/scan.c), causing the WARN_ON()
in ieee80211_ibss_csa_beacon() to get triggered (check line 500
of net/mac80211/ibss.c), which was consequently reported on the
syzkaller dashboard.
Thus, check if we have an existing connection before generating
the CSA beacon in ieee80211_ibss_finish_csa().
During cdrom emulation, the response to read_toc command must contain
the cdrom address as the number of sectors (2048 byte sized blocks)
represented either as an absolute value (when MSF bit is '0') or in
terms of PMin/PSec/PFrame (when MSF bit is set to '1'). Incase of
cdrom, the fsg_lun_open call sets the sector size to 2048 bytes.
When MAC OS sends a read_toc request with MSF set to '1', the
store_cdrom_address assumes that the address being provided is the
LUN size represented in 512 byte sized blocks instead of 2048. It
tries to modify the address further to convert it to 2048 byte sized
blocks and store it in MSF format. This results in data transfer
failures as the cdrom address being provided in the read_toc response
is incorrect.
This turned out not to be an error in usb-storage but rather a nested
device reset attempt. That is, as the rtl8712 driver was being
unbound from a composite device in preparation for an unrelated USB
reset (that driver does not have pre_reset or post_reset callbacks),
its ->remove routine called usb_reset_device() -- thus nesting one
reset call within another.
Performing a reset as part of disconnect processing is a questionable
practice at best. However, the bug report points out that the USB
core does not have any protection against nested resets. Adding a
reset_in_progress flag and testing it will prevent such errors in the
future.
Add proper alignment for .nospec_call_table and .nospec_return_table in
vmlinux.
[hca@linux.ibm.com]: The problem with the missing alignment of the nospec
tables exist since a long time, however only since commit e6ed91fd0768
("s390/alternatives: remove padding generation code") and with
CONFIG_RELOCATABLE=n the kernel may also crash at boot time.
The above named commit reduced the size of struct alt_instr by one byte,
so its new size is 11 bytes. Therefore depending on the number of cpu
alternatives the size of the __alt_instructions array maybe odd, which
again also causes that the addresses of the nospec tables will be odd.
If the address of __nospec_call_start is odd and the kernel is compiled
With CONFIG_RELOCATABLE=n the compiler may generate code that loads the
address of __nospec_call_start with a 'larl' instruction.
This will generate incorrect code since the 'larl' instruction only works
with even addresses. In result the members of the nospec tables will be
accessed with an off-by-one offset, which subsequently may lead to
addressing exceptions within __nospec_revert().
The alignment check in prepare_hugepage_range() is wrong for 2 GB
hugepages, it only checks for 1 MB hugepage alignment.
This can result in kernel crash in __unmap_hugepage_range() at the
BUG_ON(start & ~huge_page_mask(h)) alignment check, for mappings
created with MAP_FIXED at unaligned address.
Fix this by correctly handling multiple hugepage sizes, similar to the
generic version of prepare_hugepage_range().
Fixes: d08de8e2d867 ("s390/mm: add support for 2GB hugepages") Cc: <stable@vger.kernel.org> # 4.8+ Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since 1599069a62c6 ("phy: core: Warn when phy_power_on is called before
phy_init") the driver complains. In my case (Amlogic SoC) the warning
is: phy phy-fe03e000.phy.2: phy_power_on was called before phy_init
So change the order of the two calls. The same change has to be done
to the order of phy_exit() and phy_power_off().
Fix incorrect pin assignment values when connecting to a monitor with
Type-C receptacle instead of a plug.
According to specification, an UFP_D receptacle's pin assignment
should came from the UFP_D pin assignments field (bit 23:16), while
an UFP_D plug's assignments are described in the DFP_D pin assignments
(bit 15:8) during Mode Discovery.
For example the LG 27 UL850-W is a monitor with Type-C receptacle.
The monitor responds to MODE DISCOVERY command with following
DisplayPort Capability flag:
dp->alt->vdo=0x140045
The existing logic only take cares of UPF_D plug case,
and would take the bit 15:8 for this 0x140045 case.
This results in an non-existing pin assignment 0x0 in
dp_altmode_configure.
To fix this problem a new set of macros are introduced
to take plug/receptacle differences into consideration.
Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode") Cc: stable@vger.kernel.org Co-developed-by: Pablo Sun <pablo.sun@mediatek.com> Co-developed-by: Macpaul Lin <macpaul.lin@mediatek.com> Reviewed-by: Guillaume Ranquet <granquet@baylibre.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Pablo Sun <pablo.sun@mediatek.com> Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com> Link: https://lore.kernel.org/r/20220804034803.19486-1-macpaul.lin@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After xHC controller is started, either in probe or resume, it can take
a while before any of the connected usb devices are visible to the roothub
due to link training.
It's possible xhci driver loads, sees no acivity and suspends the host
before the USB device is visible.
In one testcase with a hotplugged xHC controller the host finally detected
the connected USB device and generated a wake 500ms after host initial
start.
If hosts didn't suspend the device duringe training it probablty wouldn't
take up to 500ms to detect it, but looking at specs reveal USB3 link
training has a couple long timeout values, such as 120ms
RxDetectQuietTimeout, and 360ms PollingLFPSTimeout.
So Add a 500ms grace period that keeps polling the roothub for 500ms after
start, preventing runtime suspend until USB devices are detected.
The received notification packet is held in pkg->buffer and not in pkg
itself. Fix this by using the correct buffer.
Fixes: 81a54b5e1986 ("thunderbolt: Let the connection manager handle all notifications") Cc: stable@vger.kernel.org Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver does not check if the cooling state passed to
gpio_fan_set_cur_state() exceeds the maximum cooling state as
stored in fan_data->num_speeds. Since the cooling state is later
used as an array index in set_fan_speed(), an array out of bounds
access can occur.
This can be exploited by setting the state of the thermal cooling device
to arbitrary values, causing for example a kernel oops when unavailable
memory is accessed this way.
In the original commit 9a34b45397e5 ("clk: Add support for runtime PM"),
the commit message mentioned that pm_runtime_put_sync() would be done
at the end of clk_core_unprepare(). This mirrors the operations in
clk_core_prepare() in the opposite order.
However, the actual code that was added wasn't in the order the commit
message described. Move clk_pm_runtime_put() to the end of
clk_core_unprepare() so that it is in the correct order.
Fixes: 9a34b45397e5 ("clk: Add support for runtime PM") Signed-off-by: Chen-Yu Tsai <wenst@chromium.org> Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Link: https://lore.kernel.org/r/20220822081424.1310926-3-wenst@chromium.org Signed-off-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
This reverts commit 35b0fac808b95eea1212f8860baf6ad25b88b087. Alexander
reports that it causes boot failures on i.MX8M Plus based boards
(specifically imx8mp-tqma8mpql-mba8mpxl.dts).
In the previous commits that added CLK_OPS_PARENT_ENABLE, support for
this flag was only added to rate change operations (rate setting and
reparent) and disabling unused subtree. It was not added to the
clock gate related operations. Any hardware driver that needs it for
these operations will either see bogus results, or worse, hang.
This has been seen on MT8192 and MT8195, where the imp_ii2_* clk
drivers set this, but dumping debugfs clk_summary would cause it
to hang.
Fixes: fc8726a2c021 ("clk: core: support clocks which requires parents enable (part 2)") Fixes: a4b3518d146f ("clk: core: support clocks which requires parents enable (part 1)") Signed-off-by: Chen-Yu Tsai <wenst@chromium.org> Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Link: https://lore.kernel.org/r/20220822081424.1310926-2-wenst@chromium.org Signed-off-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
There is a spelling mistake in a gvt_vgpu_err error message. Fix it.
Fixes: 695fbc08d80f ("drm/i915/gvt: replace the gvt_err with gvt_vgpu_err") Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Signed-off-by: Zhi Wang <zhi.a.wang@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20220315202449.2952845-1-colin.i.king@gmail.com Reviewed-by: Zhi Wang <zhi.a.wang@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
A transaction of type BINDER_TYPE_WEAK_HANDLE can fail to increment the
reference for a node. In this case, the target proc normally releases
the failed reference upon close as expected. However, if the target is
dying in parallel the call will race with binder_deferred_release(), so
the target could have released all of its references by now leaving the
cleanup of the new failed reference unhandled.
The transaction then ends and the target proc gets released making the
ref->proc now a dangling pointer. Later on, ref->node is closed and we
attempt to take spin_lock(&ref->proc->inner_lock), which leads to the
use-after-free bug reported below. Let's fix this by cleaning up the
failed reference on the spot instead of relying on the target to do so.
==================================================================
BUG: KASAN: use-after-free in _raw_spin_lock+0xa8/0x150
Write of size 4 at addr ffff5ca207094238 by task kworker/1:0/590
When changing the console font with ioctl(KDFONTOP) the new font size
can be bigger than the previous font. A previous selection may thus now
be outside of the new screen size and thus trigger out-of-bounds
accesses to graphics memory if the selection is removed in
vc_do_resize().
Prevent such out-of-memory accesses by dropping the selection before the
various con_font_set() console handlers are called.
_Read/Write_MACREG callbacks are NULL so the read/write_macreg_hdl()
functions don't do anything except free the "pcmd" pointer. It
results in a use after free. Delete them.
Fixes: 2865d42c78a9 ("staging: r8712u: Add the new driver to the mainline kernel") Cc: stable <stable@kernel.org> Reported-by: Zheng Wang <hackerzheng666@gmail.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/Yw4ASqkYcUhUfoY2@kili Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The setting of RS485 RTS polarity is inverse in the current driver.
When the property of 'rs485-rts-active-low' is enabled in the dts node,
the RTS signal should be LOW during sending. Otherwise, if there is no
such a property, the RTS should be HIGH during sending.
Fixes: 03895cf41d18 ("tty: serial: fsl_lpuart: Add support for RS-485") Cc: stable <stable@kernel.org> Signed-off-by: Nicolas Diaz <nicolas.diaz@nxp.com> Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com> Link: https://lore.kernel.org/r/20220805144529.604856-1-shenwei.wang@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For passive connections, the refcount increment has been done in
smc_clcsock_accept()-->smc_sock_alloc().
Fixes: 3b2dec2603d5 ("net/smc: restructure client and server code in af_smc") Signed-off-by: Yacan Liu <liuyacan@corp.netease.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Link: https://lore.kernel.org/r/20220830152314.838736-1-liuyacan@corp.netease.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
When the GSO splitting feature of sch_cake is enabled, GSO superpackets
will be broken up and the resulting segments enqueued in place of the
original skb. In this case, CAKE calls consume_skb() on the original skb,
but still returns NET_XMIT_SUCCESS. This can confuse parent qdiscs into
assuming the original skb still exists, when it really has been freed. Fix
this by adding the __NET_XMIT_STOLEN flag to the return value in this case.
strp_init() is called just a few lines above this csk->sk_user_data
check, it also initializes strp->work etc., therefore, it is
unnecessary to call strp_done() to cancel the freshly initialized
work.
And if sk_user_data is already used by KCM, psock->strp should not be
touched, particularly strp->work state, so we need to move strp_init()
after the csk->sk_user_data check.
This also makes a lockdep warning reported by syzbot go away.
Reported-and-tested-by: syzbot+9fc084a4348493ef65d2@syzkaller.appspotmail.com Reported-by: syzbot+e696806ef96cdd2d87cd@syzkaller.appspotmail.com Fixes: e5571240236c ("kcm: Check if sk_user_data already set in kcm_attach") Fixes: dff8baa26117 ("kcm: Call strp_stop before strp_done in kcm_attach") Cc: Tom Herbert <tom@herbertland.com> Signed-off-by: Cong Wang <cong.wang@bytedance.com> Link: https://lore.kernel.org/r/20220827181314.193710-1-xiyou.wangcong@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
The function neigh_timer_handler() is a timer handler that runs in an
atomic context. When used by rocker, neigh_timer_handler() calls
"kzalloc(.., GFP_KERNEL)" that may sleep. As a result, the sleep in
atomic context bug will happen. One of the processes is shown below:
This patch changes the gfp_t parameter of kzalloc() from GFP_KERNEL to
GFP_ATOMIC in order to mitigate the bug.
Fixes: 00fc0c51e35b ("rocker: Change world_ops API and implementation to be switchdev independant") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
Turning off port power in shutdown did cause issues such as a laptop not
proprly powering off, and some specific usb devies failing to enumerate the
subsequent boot after a warm reset.
So revert this.
Fixes: 83810f84ecf1 ("xhci: turn off port power in shutdown") Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20220825150840.132216-4-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
The return type is supposed to be ssize_t, which is signed long,
but "r" was declared as unsigned int. This means that on 64 bit systems
we return positive values instead of negative error codes.
The root cause for this race is that the upper layer (ieee802154) is
unaware of this detaching event and the function adf7242_channel can
be called without any checks.
To fix this, we can add a flag write at the beginning of adf7242_remove
and add flag check in adf7242_channel. Or we can just defer the
destructive operation like other commit 3e0588c291d6 ("hamradio: defer
ax25 kfree after unregister_netdev") which let the
ieee802154_unregister_hw() to handle the synchronization. This patch
takes the second option.
Fixes: 58e9683d1475 ("net: ieee802154: adf7242: Fix OCL calibration
runs") Signed-off-by: Lin Ma <linma@zju.edu.cn> Acked-by: Michael Hennerich <michael.hennerich@analog.com> Link: https://lore.kernel.org/r/20220808034224.12642-1-linma@zju.edu.cn Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
On Intel hardware the SLP_TYPx bitfield occupies bits 10-12 as per ACPI
specification (see Table 4.13 "PM1 Control Registers Fixed Hardware
Feature Control Bits" for the details).
Fix the mask and other related definitions accordingly.
Fixes: 93e5eadd1f6e ("x86/platform: New Intel Atom SOC power management controller driver") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220801113734.36131-1-andriy.shevchenko@linux.intel.com Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
When unplugging an Ethernet cable, false carrier events were produced by
the PHY at a very high rate. Once the false carrier counter full, an
interrupt was triggered every few clock cycles until the cable was
replugged. This resulted in approximately 10k/s interrupts.
Since the false carrier counter (FCSCR) is never used, we can safely
disable this interrupt.
In addition to improving performance, this also solved MDIO read
timeouts I was randomly encountering with an i.MX8 fec MAC because of
the interrupt flood. The interrupt count and MDIO timeout fix were
tested on a v5.4.110 kernel.
Fixes: 87461f7a58ab ("net: phy: DP83822 initial driver submission") Signed-off-by: Enguerrand de Ribaucourt <enguerrand.de-ribaucourt@savoirfairelinux.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 23c2d497de21 ("mm: kmemleak: take a full lowmem check in
kmemleak_*_phys()") brought false leak alarms on some archs like arm64
that does not init pfn boundary in early booting. The final solution
lands on linux-6.0: commit 0c24e061196c ("mm: kmemleak: add rbtree and
store physical address for objects allocated with PA").
Revert this commit before linux-6.0. The original issue of invalid PA
can be mitigated by additional check in devicetree.
Commit d4252071b97d ("add barriers to buffer_uptodate and
set_buffer_uptodate") added proper memory barriers to the buffer head
BH_Uptodate bit, so that anybody who tests a buffer for being up-to-date
will be guaranteed to actually see initialized state.
However, that commit didn't _just_ add the memory barrier, it also ended
up dropping the "was it already set" logic that the BUFFER_FNS() macro
had.
That's conceptually the right thing for a generic "this is a memory
barrier" operation, but in the case of the buffer contents, we really
only care about the memory barrier for the _first_ time we set the bit,
in that the only memory ordering protection we need is to avoid anybody
seeing uninitialized memory contents.
Any other access ordering wouldn't be about the BH_Uptodate bit anyway,
and would require some other proper lock (typically BH_Lock or the folio
lock). A reader that races with somebody invalidating the buffer head
isn't an issue wrt the memory ordering, it's a serialization issue.
Now, you'd think that the buffer head operations don't matter in this
day and age (and I certainly thought so), but apparently some loads
still end up being heavy users of buffer heads. In particular, the
kernel test robot reported that not having this bit access optimization
in place caused a noticeable direct IO performance regression on ext4:
This reverts commit a8eb8e6f7159c7c20c0ddac428bde3d110890aa7 as
it can cause invalid link quality command sent to the firmware
and address the off-by-one issue by fixing condition of while loop.
Cc: stable@vger.kernel.org Fixes: a8eb8e6f7159 ("wifi: iwlegacy: 4965: fix potential off-by-one overflow in il4965_rs_fill_link_cmd()") Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl> Signed-off-by: Kalle Valo <kvalo@kernel.org> Link: https://lore.kernel.org/r/20220815073737.GA999388@wp.pl Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A race condition may occur if the user calls close() on another thread
during a write() operation on the device node of the efi capsule.
This is a race condition that occurs between the efi_capsule_write() and
efi_capsule_flush() functions of efi_capsule_fops, which ultimately
results in UAF.
So, the page freeing process is modified to be done in
efi_capsule_release() instead of efi_capsule_flush().
Both __device_attach_driver() and __driver_attach() check the return
code of the bus_type.match() function to see if the device needs to be
added to the deferred probe list. After adding the device to the list,
the logic attempts to bind the device to the driver anyway, as if the
device had matched with the driver, which is not correct.
If __device_attach_driver() detects that the device in question is not
ready to match with a driver on the bus, then it doesn't make sense for
the device to attempt to bind with the current driver or continue
attempting to match with any of the other drivers on the bus. So, update
the logic in __device_attach_driver() to reflect this.
If __driver_attach() detects that a driver tried to match with a device
that is not ready to match yet, then the driver should not attempt to bind
with the device. However, the driver can still attempt to match and bind
with other devices on the bus, as drivers can be bound to multiple
devices. So, update the logic in __driver_attach() to reflect this.
It is not allowed to call kfree_skb() from hardware interrupt
context or with interrupts being disabled. So add all skb to
a tmp list, then free them after spin_unlock_irqrestore() at
once.
Fixes: 66ba215cb513 ("neigh: fix possible DoS due to net iface start/stop loop") Suggested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.
Normal processing of ARP request (usually this is Ethernet broadcast
packet) coming to the host is looking like the following:
* the packet comes to arp_process() call and is passed through routing
procedure
* the request is put into the queue using pneigh_enqueue() if
corresponding ARP record is not local (common case for container
records on the host)
* the request is processed by timer (within 80 jiffies by default) and
ARP reply is sent from the same arp_process() using
NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED condition (flag is set inside
pneigh_enqueue())
And here the problem comes. Linux kernel calls pneigh_queue_purge()
which destroys the whole queue of ARP requests on ANY network interface
start/stop event through __neigh_ifdown().
This is actually not a problem within the original world as network
interface start/stop was accessible to the host 'root' only, which
could do more destructive things. But the world is changed and there
are Linux containers available. Here container 'root' has an access
to this API and could be considered as untrusted user in the hosting
(container's) world.
Thus there is an attack vector to other containers on node when
container's root will endlessly start/stop interfaces. We have observed
similar situation on a real production node when docker container was
doing such activity and thus other containers on the node become not
accessible.
The patch proposed doing very simple thing. It drops only packets from
the same namespace in the pneigh_queue_purge() where network interface
state change is detected. This is enough to prevent the problem for the
whole node preserving original semantics of the code.
v2:
- do del_timer_sync() if queue is empty after pneigh_queue_purge()
v3:
- rebase to net tree
Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Ahern <dsahern@kernel.org> Cc: Yajun Deng <yajun.deng@linux.dev> Cc: Roopa Prabhu <roopa@nvidia.com> Cc: Christian Brauner <brauner@kernel.org> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> Cc: Konstantin Khorenko <khorenko@virtuozzo.com> Cc: kernel@openvz.org Cc: devel@openvz.org Investigated-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
[Why]
After ODM clock off, optc underflow bit will be kept there always and clear not work.
We need to clear that before clock off.
[How]
Clear that if have when clock off.
Reviewed-by: Alvin Lee <alvin.lee2@amd.com> Acked-by: Tom Chung <chiahsuan.chung@amd.com> Signed-off-by: Fudong Wang <Fudong.Wang@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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.
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.