| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
smb/server: fix possible memory leak in smb2_read()
Memory leak occurs when ksmbd_vfs_read() fails.
Fix this by adding the missing kvfree(). |
| In the Linux kernel, the following vulnerability has been resolved:
exfat: fix improper check of dentry.stream.valid_size
We found an infinite loop bug in the exFAT file system that can lead to a
Denial-of-Service (DoS) condition. When a dentry in an exFAT filesystem is
malformed, the following system calls — SYS_openat, SYS_ftruncate, and
SYS_pwrite64 — can cause the kernel to hang.
Root cause analysis shows that the size validation code in exfat_find()
does not check whether dentry.stream.valid_size is negative. As a result,
the system calls mentioned above can succeed and eventually trigger the DoS
issue.
This patch adds a check for negative dentry.stream.valid_size to prevent
this vulnerability. |
| In the Linux kernel, the following vulnerability has been resolved:
fscrypt: fix left shift underflow when inode->i_blkbits > PAGE_SHIFT
When simulating an nvme device on qemu with both logical_block_size and
physical_block_size set to 8 KiB, an error trace appears during
partition table reading at boot time. The issue is caused by
inode->i_blkbits being larger than PAGE_SHIFT, which leads to a left
shift of -1 and triggering a UBSAN warning.
[ 2.697306] ------------[ cut here ]------------
[ 2.697309] UBSAN: shift-out-of-bounds in fs/crypto/inline_crypt.c:336:37
[ 2.697311] shift exponent -1 is negative
[ 2.697315] CPU: 3 UID: 0 PID: 274 Comm: (udev-worker) Not tainted 6.18.0-rc2+ #34 PREEMPT(voluntary)
[ 2.697317] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 2.697320] Call Trace:
[ 2.697324] <TASK>
[ 2.697325] dump_stack_lvl+0x76/0xa0
[ 2.697340] dump_stack+0x10/0x20
[ 2.697342] __ubsan_handle_shift_out_of_bounds+0x1e3/0x390
[ 2.697351] bh_get_inode_and_lblk_num.cold+0x12/0x94
[ 2.697359] fscrypt_set_bio_crypt_ctx_bh+0x44/0x90
[ 2.697365] submit_bh_wbc+0xb6/0x190
[ 2.697370] block_read_full_folio+0x194/0x270
[ 2.697371] ? __pfx_blkdev_get_block+0x10/0x10
[ 2.697375] ? __pfx_blkdev_read_folio+0x10/0x10
[ 2.697377] blkdev_read_folio+0x18/0x30
[ 2.697379] filemap_read_folio+0x40/0xe0
[ 2.697382] filemap_get_pages+0x5ef/0x7a0
[ 2.697385] ? mmap_region+0x63/0xd0
[ 2.697389] filemap_read+0x11d/0x520
[ 2.697392] blkdev_read_iter+0x7c/0x180
[ 2.697393] vfs_read+0x261/0x390
[ 2.697397] ksys_read+0x71/0xf0
[ 2.697398] __x64_sys_read+0x19/0x30
[ 2.697399] x64_sys_call+0x1e88/0x26a0
[ 2.697405] do_syscall_64+0x80/0x670
[ 2.697410] ? __x64_sys_newfstat+0x15/0x20
[ 2.697414] ? x64_sys_call+0x204a/0x26a0
[ 2.697415] ? do_syscall_64+0xb8/0x670
[ 2.697417] ? irqentry_exit_to_user_mode+0x2e/0x2a0
[ 2.697420] ? irqentry_exit+0x43/0x50
[ 2.697421] ? exc_page_fault+0x90/0x1b0
[ 2.697422] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 2.697425] RIP: 0033:0x75054cba4a06
[ 2.697426] Code: 5d e8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 75 19 83 e2 39 83 fa 08 75 11 e8 26 ff ff ff 66 0f 1f 44 00 00 48 8b 45 10 0f 05 <48> 8b 5d f8 c9 c3 0f 1f 40 00 f3 0f 1e fa 55 48 89 e5 48 83 ec 08
[ 2.697427] RSP: 002b:00007fff973723a0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
[ 2.697430] RAX: ffffffffffffffda RBX: 00005ea9a2c02760 RCX: 000075054cba4a06
[ 2.697432] RDX: 0000000000002000 RSI: 000075054c190000 RDI: 000000000000001b
[ 2.697433] RBP: 00007fff973723c0 R08: 0000000000000000 R09: 0000000000000000
[ 2.697434] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
[ 2.697434] R13: 00005ea9a2c027c0 R14: 00005ea9a2be5608 R15: 00005ea9a2be55f0
[ 2.697436] </TASK>
[ 2.697436] ---[ end trace ]---
This situation can happen for block devices because when
CONFIG_TRANSPARENT_HUGEPAGE is enabled, the maximum logical_block_size
is 64 KiB. set_init_blocksize() then sets the block device
inode->i_blkbits to 13, which is within this limit.
File I/O does not trigger this problem because for filesystems that do
not support the FS_LBS feature, sb_set_blocksize() prevents
sb->s_blocksize_bits from being larger than PAGE_SHIFT. During inode
allocation, alloc_inode()->inode_init_always() assigns inode->i_blkbits
from sb->s_blocksize_bits. Currently, only xfs_fs_type has the FS_LBS
flag, and since xfs I/O paths do not reach submit_bh_wbc(), it does not
hit the left-shift underflow issue.
[EB: use folio_pos() and consolidate the two shifts by i_blkbits] |
| In the Linux kernel, the following vulnerability has been resolved:
platform/x86: int3472: Fix double free of GPIO device during unregister
regulator_unregister() already frees the associated GPIO device. On
ThinkPad X9 (Lunar Lake), this causes a double free issue that leads to
random failures when other drivers (typically Intel THC) attempt to
allocate interrupts. The root cause is that the reference count of the
pinctrl_intel_platform module unexpectedly drops to zero when this
driver defers its probe.
This behavior can also be reproduced by unloading the module directly.
Fix the issue by removing the redundant release of the GPIO device
during regulator unregistration. |
| In the Linux kernel, the following vulnerability has been resolved:
gve: Implement settime64 with -EOPNOTSUPP
ptp_clock_settime() assumes every ptp_clock has implemented settime64().
Stub it with -EOPNOTSUPP to prevent a NULL dereference. |
| In the Linux kernel, the following vulnerability has been resolved:
amd/amdkfd: resolve a race in amdgpu_amdkfd_device_fini_sw
There is race in amdgpu_amdkfd_device_fini_sw and interrupt.
if amdgpu_amdkfd_device_fini_sw run in b/w kfd_cleanup_nodes and
kfree(kfd), and KGD interrupt generated.
kernel panic log:
BUG: kernel NULL pointer dereference, address: 0000000000000098
amdgpu 0000:c8:00.0: amdgpu: Requesting 4 partitions through PSP
PGD d78c68067 P4D d78c68067
kfd kfd: amdgpu: Allocated 3969056 bytes on gart
PUD 1465b8067 PMD @
Oops: @002 [#1] SMP NOPTI
kfd kfd: amdgpu: Total number of KFD nodes to be created: 4
CPU: 115 PID: @ Comm: swapper/115 Kdump: loaded Tainted: G S W OE K
RIP: 0010:_raw_spin_lock_irqsave+0x12/0x40
Code: 89 e@ 41 5c c3 cc cc cc cc 66 66 2e Of 1f 84 00 00 00 00 00 OF 1f 40 00 Of 1f 44% 00 00 41 54 9c 41 5c fa 31 cO ba 01 00 00 00 <fO> OF b1 17 75 Ba 4c 89 e@ 41 Sc
89 c6 e8 07 38 5d
RSP: 0018: ffffc90@1a6b0e28 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000018
0000000000000001 RSI: ffff8883bb623e00 RDI: 0000000000000098
ffff8883bb000000 RO8: ffff888100055020 ROO: ffff888100055020
0000000000000000 R11: 0000000000000000 R12: 0900000000000002
ffff888F2b97da0@ R14: @000000000000098 R15: ffff8883babdfo00
CS: 010 DS: 0000 ES: 0000 CRO: 0000000080050033
CR2: 0000000000000098 CR3: 0000000e7cae2006 CR4: 0000000002770ce0
0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
0000000000000000 DR6: 00000000fffeO7FO DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<IRQ>
kgd2kfd_interrupt+@x6b/0x1f@ [amdgpu]
? amdgpu_fence_process+0xa4/0x150 [amdgpu]
kfd kfd: amdgpu: Node: 0, interrupt_bitmap: 3 YcpxFl Rant tErace
amdgpu_irq_dispatch+0x165/0x210 [amdgpu]
amdgpu_ih_process+0x80/0x100 [amdgpu]
amdgpu: Virtual CRAT table created for GPU
amdgpu_irq_handler+0x1f/@x60 [amdgpu]
__handle_irq_event_percpu+0x3d/0x170
amdgpu: Topology: Add dGPU node [0x74a2:0x1002]
handle_irq_event+0x5a/@xcO
handle_edge_irq+0x93/0x240
kfd kfd: amdgpu: KFD node 1 partition @ size 49148M
asm_call_irq_on_stack+0xf/@x20
</IRQ>
common_interrupt+0xb3/0x130
asm_common_interrupt+0x1le/0x40
5.10.134-010.a1i5000.a18.x86_64 #1 |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmfmac: fix crash while sending Action Frames in standalone AP Mode
Currently, whenever there is a need to transmit an Action frame,
the brcmfmac driver always uses the P2P vif to send the "actframe" IOVAR to
firmware. The P2P interfaces were available when wpa_supplicant is managing
the wlan interface.
However, the P2P interfaces are not created/initialized when only hostapd
is managing the wlan interface. And if hostapd receives an ANQP Query REQ
Action frame even from an un-associated STA, the brcmfmac driver tries
to use an uninitialized P2P vif pointer for sending the IOVAR to firmware.
This NULL pointer dereferencing triggers a driver crash.
[ 1417.074538] Unable to handle kernel NULL pointer dereference at virtual
address 0000000000000000
[...]
[ 1417.075188] Hardware name: Raspberry Pi 4 Model B Rev 1.5 (DT)
[...]
[ 1417.075653] Call trace:
[ 1417.075662] brcmf_p2p_send_action_frame+0x23c/0xc58 [brcmfmac]
[ 1417.075738] brcmf_cfg80211_mgmt_tx+0x304/0x5c0 [brcmfmac]
[ 1417.075810] cfg80211_mlme_mgmt_tx+0x1b0/0x428 [cfg80211]
[ 1417.076067] nl80211_tx_mgmt+0x238/0x388 [cfg80211]
[ 1417.076281] genl_family_rcv_msg_doit+0xe0/0x158
[ 1417.076302] genl_rcv_msg+0x220/0x2a0
[ 1417.076317] netlink_rcv_skb+0x68/0x140
[ 1417.076330] genl_rcv+0x40/0x60
[ 1417.076343] netlink_unicast+0x330/0x3b8
[ 1417.076357] netlink_sendmsg+0x19c/0x3f8
[ 1417.076370] __sock_sendmsg+0x64/0xc0
[ 1417.076391] ____sys_sendmsg+0x268/0x2a0
[ 1417.076408] ___sys_sendmsg+0xb8/0x118
[ 1417.076427] __sys_sendmsg+0x90/0xf8
[ 1417.076445] __arm64_sys_sendmsg+0x2c/0x40
[ 1417.076465] invoke_syscall+0x50/0x120
[ 1417.076486] el0_svc_common.constprop.0+0x48/0xf0
[ 1417.076506] do_el0_svc+0x24/0x38
[ 1417.076525] el0_svc+0x30/0x100
[ 1417.076548] el0t_64_sync_handler+0x100/0x130
[ 1417.076569] el0t_64_sync+0x190/0x198
[ 1417.076589] Code: f9401e80 aa1603e2 f9403be1 5280e483 (f9400000)
Fix this, by always using the vif corresponding to the wdev on which the
Action frame Transmission request was initiated by the userspace. This way,
even if P2P vif is not available, the IOVAR is sent to firmware on AP vif
and the ANQP Query RESP Action frame is transmitted without crashing the
driver.
Move init_completion() for "send_af_done" from brcmf_p2p_create_p2pdev()
to brcmf_p2p_attach(). Because the former function would not get executed
when only hostapd is managing wlan interface, and it is not safe to do
reinit_completion() later in brcmf_p2p_tx_action_frame(), without any prior
init_completion().
And in the brcmf_p2p_tx_action_frame() function, the condition check for
P2P Presence response frame is not needed, since the wpa_supplicant is
properly sending the P2P Presense Response frame on the P2P-GO vif instead
of the P2P-Device vif.
[Cc stable] |
| In the Linux kernel, the following vulnerability has been resolved:
perf/core: Fix system hang caused by cpu-clock usage
cpu-clock usage by the async-profiler tool can trigger a system hang,
which got bisected back to the following commit by Octavia Togami:
18dbcbfabfff ("perf: Fix the POLL_HUP delivery breakage") causes this issue
The root cause of the hang is that cpu-clock is a special type of SW
event which relies on hrtimers. The __perf_event_overflow() callback
is invoked from the hrtimer handler for cpu-clock events, and
__perf_event_overflow() tries to call cpu_clock_event_stop()
to stop the event, which calls htimer_cancel() to cancel the hrtimer.
But that's a recursion into the hrtimer code from a hrtimer handler,
which (unsurprisingly) deadlocks.
To fix this bug, use hrtimer_try_to_cancel() instead, and set
the PERF_HES_STOPPED flag, which causes perf_swevent_hrtimer()
to stop the event once it sees the PERF_HES_STOPPED flag.
[ mingo: Fixed the comments and improved the changelog. ] |
| In the Linux kernel, the following vulnerability has been resolved:
arch_topology: Fix incorrect error check in topology_parse_cpu_capacity()
Fix incorrect use of PTR_ERR_OR_ZERO() in topology_parse_cpu_capacity()
which causes the code to proceed with NULL clock pointers. The current
logic uses !PTR_ERR_OR_ZERO(cpu_clk) which evaluates to true for both
valid pointers and NULL, leading to potential NULL pointer dereference
in clk_get_rate().
Per include/linux/err.h documentation, PTR_ERR_OR_ZERO(ptr) returns:
"The error code within @ptr if it is an error pointer; 0 otherwise."
This means PTR_ERR_OR_ZERO() returns 0 for both valid pointers AND NULL
pointers. Therefore !PTR_ERR_OR_ZERO(cpu_clk) evaluates to true (proceed)
when cpu_clk is either valid or NULL, causing clk_get_rate(NULL) to be
called when of_clk_get() returns NULL.
Replace with !IS_ERR_OR_NULL(cpu_clk) which only proceeds for valid
pointers, preventing potential NULL pointer dereference in clk_get_rate(). |
| In the Linux kernel, the following vulnerability has been resolved:
slab: Avoid race on slab->obj_exts in alloc_slab_obj_exts
If two competing threads enter alloc_slab_obj_exts() and one of them
fails to allocate the object extension vector, it might override the
valid slab->obj_exts allocated by the other thread with
OBJEXTS_ALLOC_FAIL. This will cause the thread that lost this race and
expects a valid pointer to dereference a NULL pointer later on.
Update slab->obj_exts atomically using cmpxchg() to avoid
slab->obj_exts overrides by racing threads.
Thanks for Vlastimil and Suren's help with debugging. |
| In the Linux kernel, the following vulnerability has been resolved:
net/smc: fix general protection fault in __smc_diag_dump
The syzbot report a crash:
Oops: general protection fault, probably for non-canonical address 0xfbd5a5d5a0000003: 0000 [#1] SMP KASAN NOPTI
KASAN: maybe wild-memory-access in range [0xdead4ead00000018-0xdead4ead0000001f]
CPU: 1 UID: 0 PID: 6949 Comm: syz.0.335 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:smc_diag_msg_common_fill net/smc/smc_diag.c:44 [inline]
RIP: 0010:__smc_diag_dump.constprop.0+0x3ca/0x2550 net/smc/smc_diag.c:89
Call Trace:
<TASK>
smc_diag_dump_proto+0x26d/0x420 net/smc/smc_diag.c:217
smc_diag_dump+0x27/0x90 net/smc/smc_diag.c:234
netlink_dump+0x539/0xd30 net/netlink/af_netlink.c:2327
__netlink_dump_start+0x6d6/0x990 net/netlink/af_netlink.c:2442
netlink_dump_start include/linux/netlink.h:341 [inline]
smc_diag_handler_dump+0x1f9/0x240 net/smc/smc_diag.c:251
__sock_diag_cmd net/core/sock_diag.c:249 [inline]
sock_diag_rcv_msg+0x438/0x790 net/core/sock_diag.c:285
netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg net/socket.c:729 [inline]
____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
__sys_sendmsg+0x16d/0x220 net/socket.c:2700
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
The process like this:
(CPU1) | (CPU2)
---------------------------------|-------------------------------
inet_create() |
// init clcsock to NULL |
sk = sk_alloc() |
|
// unexpectedly change clcsock |
inet_init_csk_locks() |
|
// add sk to hash table |
smc_inet_init_sock() |
smc_sk_init() |
smc_hash_sk() |
| // traverse the hash table
| smc_diag_dump_proto
| __smc_diag_dump()
| // visit wrong clcsock
| smc_diag_msg_common_fill()
// alloc clcsock |
smc_create_clcsk |
sock_create_kern |
With CONFIG_DEBUG_LOCK_ALLOC=y, the smc->clcsock is unexpectedly changed
in inet_init_csk_locks(). The INET_PROTOSW_ICSK flag is no need by smc,
just remove it.
After removing the INET_PROTOSW_ICSK flag, this patch alse revert
commit 6fd27ea183c2 ("net/smc: fix lacks of icsk_syn_mss with IPPROTO_SMC")
to avoid casting smc_sock to inet_connection_sock. |
| In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel: Fix KASAN global-out-of-bounds warning
When running "perf mem record" command on CWF, the below KASAN
global-out-of-bounds warning is seen.
==================================================================
BUG: KASAN: global-out-of-bounds in cmt_latency_data+0x176/0x1b0
Read of size 4 at addr ffffffffb721d000 by task dtlb/9850
Call Trace:
kasan_report+0xb8/0xf0
cmt_latency_data+0x176/0x1b0
setup_arch_pebs_sample_data+0xf49/0x2560
intel_pmu_drain_arch_pebs+0x577/0xb00
handle_pmi_common+0x6c4/0xc80
The issue is caused by below code in __grt_latency_data(). The code
tries to access x86_hybrid_pmu structure which doesn't exist on
non-hybrid platform like CWF.
WARN_ON_ONCE(hybrid_pmu(event->pmu)->pmu_type == hybrid_big)
So add is_hybrid() check before calling this WARN_ON_ONCE to fix the
global-out-of-bounds access issue. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/sysfb: Do not dereference NULL pointer in plane reset
The plane state in __drm_gem_reset_shadow_plane() can be NULL. Do not
deref that pointer, but forward NULL to the other plane-reset helpers.
Clears plane->state to NULL.
v2:
- fix typo in commit description (Javier) |
| The Qualys Cloud Agent included a bundled uninstall script (qagent_uninstall.sh), specific to Mac and Linux supported versions that invoked multiple system commands without using absolute paths and without sanitizing the $PATH environment. If the uninstall script is executed with elevated privileges (e.g., via sudo) in an environment where $PATH has been manipulated, an attacker with root/sudo privileges could cause malicious executables to be run in place of the intended system binaries. This behavior can be leveraged for local privilege escalation and arbitrary command execution under elevated privileges. |
| PureVPN client applications on Linux through September 2025 allow IPv6 traffic to leak outside the VPN tunnel upon network events such as Wi-Fi reconnect or system resume. In the CLI client, the VPN auto-reconnects and claims to be connected, but IPv6 traffic is no longer routed or blocked. In the GUI client, the IPv6 connection remains functional after disconnection until the user clicks Reconnect. In both cases, the real IPv6 address is exposed to external services, violating user privacy and defeating the advertised IPv6 leak protection. This affects CLI 2.0.1 and GUI 2.10.0. |
| PureVPN client applications on Linux through September 2025 mishandle firewalling. They flush the system's existing iptables rules and apply default ACCEPT policies when connecting to a VPN server. This removes firewall rules that may have been configured manually or by other software (e.g., UFW, container engines, or system security policies). Upon VPN disconnect, the original firewall state is not restored. As a result, the system may become unintentionally exposed to network traffic that was previously blocked. This affects CLI 2.0.1 and GUI 2.10.0. |
| The Datadog Agent collects events and metrics from hosts and sends them to Datadog. A vulnerability within the Datadog Linux Host Agent versions 7.65.0 through 7.70.2 exists due to insufficient permissions being set on the `opt/datadog-agent/python-scripts/__pycache__` directory during installation. Code in this directory is only run by the Agent during Agent install/upgrades. This could allow an attacker with local access to modify files in this directory, which would then subsequently be run when the Agent is upgraded, resulting in local privilege escalation. This issue requires local access to the host and a valid low privilege account to be vulnerable. Note that this vulnerability only impacts the Linux Host Agent. Other variations of the Agent including the container, kubernetes, windows host and other agents are not impacted. Version 7.71.0 contains a patch for the issue. |
| ETERNUS SF provided by Fsas Technologies Inc. contains an incorrect default permissions vulnerability. A low-privileged user with access to the management server may obtain database credentials, potentially allowing execution of OS commands with administrator privileges. |
| In the Linux kernel, the following vulnerability has been resolved:
media: imon: make send_packet() more robust
syzbot is reporting that imon has three problems which result in
hung tasks due to forever holding device lock [1].
First problem is that when usb_rx_callback_intf0() once got -EPROTO error
after ictx->dev_present_intf0 became true, usb_rx_callback_intf0()
resubmits urb after printk(), and resubmitted urb causes
usb_rx_callback_intf0() to again get -EPROTO error. This results in
printk() flooding (RCU stalls).
Alan Stern commented [2] that
In theory it's okay to resubmit _if_ the driver has a robust
error-recovery scheme (such as giving up after some fixed limit on the
number of errors or after some fixed time has elapsed, perhaps with a
time delay to prevent a flood of errors). Most drivers don't bother to
do this; they simply give up right away. This makes them more
vulnerable to short-term noise interference during USB transfers, but in
reality such interference is quite rare. There's nothing really wrong
with giving up right away.
but imon has a poor error-recovery scheme which just retries forever;
this behavior should be fixed.
Since I'm not sure whether it is safe for imon users to give up upon any
error code, this patch takes care of only union of error codes chosen from
modules in drivers/media/rc/ directory which handle -EPROTO error (i.e.
ir_toy, mceusb and igorplugusb).
Second problem is that when usb_rx_callback_intf0() once got -EPROTO error
before ictx->dev_present_intf0 becomes true, usb_rx_callback_intf0() always
resubmits urb due to commit 8791d63af0cf ("[media] imon: don't wedge
hardware after early callbacks"). Move the ictx->dev_present_intf0 test
introduced by commit 6f6b90c9231a ("[media] imon: don't parse scancodes
until intf configured") to immediately before imon_incoming_packet(), or
the first problem explained above happens without printk() flooding (i.e.
hung task).
Third problem is that when usb_rx_callback_intf0() is not called for some
reason (e.g. flaky hardware; the reproducer for this problem sometimes
prevents usb_rx_callback_intf0() from being called),
wait_for_completion_interruptible() in send_packet() never returns (i.e.
hung task). As a workaround for such situation, change send_packet() to
wait for completion with timeout of 10 seconds. |
| In the Linux kernel, the following vulnerability has been resolved:
netpoll: Fix deadlock in memory allocation under spinlock
Fix a AA deadlock in refill_skbs() where memory allocation while holding
skb_pool->lock can trigger a recursive lock acquisition attempt.
The deadlock scenario occurs when the system is under severe memory
pressure:
1. refill_skbs() acquires skb_pool->lock (spinlock)
2. alloc_skb() is called while holding the lock
3. Memory allocator fails and calls slab_out_of_memory()
4. This triggers printk() for the OOM warning
5. The console output path calls netpoll_send_udp()
6. netpoll_send_udp() attempts to acquire the same skb_pool->lock
7. Deadlock: the lock is already held by the same CPU
Call stack:
refill_skbs()
spin_lock_irqsave(&skb_pool->lock) <- lock acquired
__alloc_skb()
kmem_cache_alloc_node_noprof()
slab_out_of_memory()
printk()
console_flush_all()
netpoll_send_udp()
skb_dequeue()
spin_lock_irqsave(&skb_pool->lock) <- deadlock attempt
This bug was exposed by commit 248f6571fd4c51 ("netpoll: Optimize skb
refilling on critical path") which removed refill_skbs() from the
critical path (where nested printk was being deferred), letting nested
printk being called from inside refill_skbs()
Refactor refill_skbs() to never allocate memory while holding
the spinlock.
Another possible solution to fix this problem is protecting the
refill_skbs() from nested printks, basically calling
printk_deferred_{enter,exit}() in refill_skbs(), then, any nested
pr_warn() would be deferred.
I prefer this approach, given I _think_ it might be a good idea to move
the alloc_skb() from GFP_ATOMIC to GFP_KERNEL in the future, so, having
the alloc_skb() outside of the lock will be necessary step.
There is a possible TOCTOU issue when checking for the pool length, and
queueing the new allocated skb, but, this is not an issue, given that
an extra SKB in the pool is harmless and it will be eventually used. |
