| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: rtl8xxxu: Fix memory leaks with RTL8723BU, RTL8192EU
The wifi + bluetooth combo chip RTL8723BU can leak memory (especially?)
when it's connected to a bluetooth audio device. The busy bluetooth
traffic generates lots of C2H (card to host) messages, which are not
freed correctly.
To fix this, move the dev_kfree_skb() call in rtl8xxxu_c2hcmd_callback()
inside the loop where skb_dequeue() is called.
The RTL8192EU leaks memory because the C2H messages are added to the
queue and left there forever. (This was fine in the past because it
probably wasn't sending any C2H messages until commit e542e66b7c2e
("wifi: rtl8xxxu: gen2: Turn on the rate control"). Since that commit
it sends a C2H message when the TX rate changes.)
To fix this, delete the check for rf_paths > 1 and the goto. Let the
function process the C2H messages from RTL8192EU like the ones from
the other chips.
Theoretically the RTL8188FU could also leak like RTL8723BU, but it
most likely doesn't send C2H messages frequently enough.
This change was tested with RTL8723BU by Erhard F. I tested it with
RTL8188FU and RTL8192EU. |
| In the Linux kernel, the following vulnerability has been resolved:
sched/psi: use kernfs polling functions for PSI trigger polling
Destroying psi trigger in cgroup_file_release causes UAF issues when
a cgroup is removed from under a polling process. This is happening
because cgroup removal causes a call to cgroup_file_release while the
actual file is still alive. Destroying the trigger at this point would
also destroy its waitqueue head and if there is still a polling process
on that file accessing the waitqueue, it will step on the freed pointer:
do_select
vfs_poll
do_rmdir
cgroup_rmdir
kernfs_drain_open_files
cgroup_file_release
cgroup_pressure_release
psi_trigger_destroy
wake_up_pollfree(&t->event_wait)
// vfs_poll is unblocked
synchronize_rcu
kfree(t)
poll_freewait -> UAF access to the trigger's waitqueue head
Patch [1] fixed this issue for epoll() case using wake_up_pollfree(),
however the same issue exists for synchronous poll() case.
The root cause of this issue is that the lifecycles of the psi trigger's
waitqueue and of the file associated with the trigger are different. Fix
this by using kernfs_generic_poll function when polling on cgroup-specific
psi triggers. It internally uses kernfs_open_node->poll waitqueue head
with its lifecycle tied to the file's lifecycle. This also renders the
fix in [1] obsolete, so revert it.
[1] commit c2dbe32d5db5 ("sched/psi: Fix use-after-free in ep_remove_wait_queue()") |
| In the Linux kernel, the following vulnerability has been resolved:
vmci_host: fix a race condition in vmci_host_poll() causing GPF
During fuzzing, a general protection fault is observed in
vmci_host_poll().
general protection fault, probably for non-canonical address 0xdffffc0000000019: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000c8-0x00000000000000cf]
RIP: 0010:__lock_acquire+0xf3/0x5e00 kernel/locking/lockdep.c:4926
<- omitting registers ->
Call Trace:
<TASK>
lock_acquire+0x1a4/0x4a0 kernel/locking/lockdep.c:5672
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:162
add_wait_queue+0x3d/0x260 kernel/sched/wait.c:22
poll_wait include/linux/poll.h:49 [inline]
vmci_host_poll+0xf8/0x2b0 drivers/misc/vmw_vmci/vmci_host.c:174
vfs_poll include/linux/poll.h:88 [inline]
do_pollfd fs/select.c:873 [inline]
do_poll fs/select.c:921 [inline]
do_sys_poll+0xc7c/0x1aa0 fs/select.c:1015
__do_sys_ppoll fs/select.c:1121 [inline]
__se_sys_ppoll+0x2cc/0x330 fs/select.c:1101
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4e/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x46/0xb0
Example thread interleaving that causes the general protection fault
is as follows:
CPU1 (vmci_host_poll) CPU2 (vmci_host_do_init_context)
----- -----
// Read uninitialized context
context = vmci_host_dev->context;
// Initialize context
vmci_host_dev->context = vmci_ctx_create();
vmci_host_dev->ct_type = VMCIOBJ_CONTEXT;
if (vmci_host_dev->ct_type == VMCIOBJ_CONTEXT) {
// Dereferencing the wrong pointer
poll_wait(..., &context->host_context);
}
In this scenario, vmci_host_poll() reads vmci_host_dev->context first,
and then reads vmci_host_dev->ct_type to check that
vmci_host_dev->context is initialized. However, since these two reads
are not atomically executed, there is a chance of a race condition as
described above.
To fix this race condition, read vmci_host_dev->context after checking
the value of vmci_host_dev->ct_type so that vmci_host_poll() always
reads an initialized context. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Add preempt_count_{sub,add} into btf id deny list
The recursion check in __bpf_prog_enter* and __bpf_prog_exit*
leave preempt_count_{sub,add} unprotected. When attaching trampoline to
them we get panic as follows,
[ 867.843050] BUG: TASK stack guard page was hit at 0000000009d325cf (stack is 0000000046a46a15..00000000537e7b28)
[ 867.843064] stack guard page: 0000 [#1] PREEMPT SMP NOPTI
[ 867.843067] CPU: 8 PID: 11009 Comm: trace Kdump: loaded Not tainted 6.2.0+ #4
[ 867.843100] Call Trace:
[ 867.843101] <TASK>
[ 867.843104] asm_exc_int3+0x3a/0x40
[ 867.843108] RIP: 0010:preempt_count_sub+0x1/0xa0
[ 867.843135] __bpf_prog_enter_recur+0x17/0x90
[ 867.843148] bpf_trampoline_6442468108_0+0x2e/0x1000
[ 867.843154] ? preempt_count_sub+0x1/0xa0
[ 867.843157] preempt_count_sub+0x5/0xa0
[ 867.843159] ? migrate_enable+0xac/0xf0
[ 867.843164] __bpf_prog_exit_recur+0x2d/0x40
[ 867.843168] bpf_trampoline_6442468108_0+0x55/0x1000
...
[ 867.843788] preempt_count_sub+0x5/0xa0
[ 867.843793] ? migrate_enable+0xac/0xf0
[ 867.843829] __bpf_prog_exit_recur+0x2d/0x40
[ 867.843837] BUG: IRQ stack guard page was hit at 0000000099bd8228 (stack is 00000000b23e2bc4..000000006d95af35)
[ 867.843841] BUG: IRQ stack guard page was hit at 000000005ae07924 (stack is 00000000ffd69623..0000000014eb594c)
[ 867.843843] BUG: IRQ stack guard page was hit at 00000000028320f0 (stack is 00000000034b6438..0000000078d1bcec)
[ 867.843842] bpf_trampoline_6442468108_0+0x55/0x1000
...
That is because in __bpf_prog_exit_recur, the preempt_count_{sub,add} are
called after prog->active is decreased.
Fixing this by adding these two functions into btf ids deny list. |
| In the Linux kernel, the following vulnerability has been resolved:
RISC-V: kexec: Fix memory leak of elf header buffer
This is reported by kmemleak detector:
unreferenced object 0xff2000000403d000 (size 4096):
comm "kexec", pid 146, jiffies 4294900633 (age 64.792s)
hex dump (first 32 bytes):
7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 .ELF............
04 00 f3 00 01 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000566ca97c>] kmemleak_vmalloc+0x3c/0xbe
[<00000000979283d8>] __vmalloc_node_range+0x3ac/0x560
[<00000000b4b3712a>] __vmalloc_node+0x56/0x62
[<00000000854f75e2>] vzalloc+0x2c/0x34
[<00000000e9a00db9>] crash_prepare_elf64_headers+0x80/0x30c
[<0000000067e8bf48>] elf_kexec_load+0x3e8/0x4ec
[<0000000036548e09>] kexec_image_load_default+0x40/0x4c
[<0000000079fbe1b4>] sys_kexec_file_load+0x1c4/0x322
[<0000000040c62c03>] ret_from_syscall+0x0/0x2
In elf_kexec_load(), a buffer is allocated via vzalloc() to store elf
headers. While it's not freed back to system when kdump kernel is
reloaded or unloaded, or when image->elf_header is successfully set and
then fails to load kdump kernel for some reason. Fix it by freeing the
buffer in arch_kimage_file_post_load_cleanup(). |
| In the Linux kernel, the following vulnerability has been resolved:
bfs: Reconstruct file type when loading from disk
syzbot is reporting that S_IFMT bits of inode->i_mode can become bogus when
the S_IFMT bits of the 32bits "mode" field loaded from disk are corrupted
or when the 32bits "attributes" field loaded from disk are corrupted.
A documentation says that BFS uses only lower 9 bits of the "mode" field.
But I can't find an explicit explanation that the unused upper 23 bits
(especially, the S_IFMT bits) are initialized with 0.
Therefore, ignore the S_IFMT bits of the "mode" field loaded from disk.
Also, verify that the value of the "attributes" field loaded from disk is
either BFS_VREG or BFS_VDIR (because BFS supports only regular files and
the root directory). |
| In the Linux kernel, the following vulnerability has been resolved:
hfs: Fix OOB Write in hfs_asc2mac
Syzbot reported a OOB Write bug:
loop0: detected capacity change from 0 to 64
==================================================================
BUG: KASAN: slab-out-of-bounds in hfs_asc2mac+0x467/0x9a0
fs/hfs/trans.c:133
Write of size 1 at addr ffff88801848314e by task syz-executor391/3632
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
print_address_description+0x74/0x340 mm/kasan/report.c:284
print_report+0x107/0x1f0 mm/kasan/report.c:395
kasan_report+0xcd/0x100 mm/kasan/report.c:495
hfs_asc2mac+0x467/0x9a0 fs/hfs/trans.c:133
hfs_cat_build_key+0x92/0x170 fs/hfs/catalog.c:28
hfs_lookup+0x1ab/0x2c0 fs/hfs/dir.c:31
lookup_open fs/namei.c:3391 [inline]
open_last_lookups fs/namei.c:3481 [inline]
path_openat+0x10e6/0x2df0 fs/namei.c:3710
do_filp_open+0x264/0x4f0 fs/namei.c:3740
If in->len is much larger than HFS_NAMELEN(31) which is the maximum
length of an HFS filename, a OOB write could occur in hfs_asc2mac(). In
that case, when the dst reaches the boundary, the srclen is still
greater than 0, which causes a OOB write.
Fix this by adding a check on dstlen in while() before writing to dst
address. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: lpfc: Fix hard lockup when reading the rx_monitor from debugfs
During I/O and simultaneous cat of /sys/kernel/debug/lpfc/fnX/rx_monitor, a
hard lockup similar to the call trace below may occur.
The spin_lock_bh in lpfc_rx_monitor_report is not protecting from timer
interrupts as expected, so change the strength of the spin lock to _irq.
Kernel panic - not syncing: Hard LOCKUP
CPU: 3 PID: 110402 Comm: cat Kdump: loaded
exception RIP: native_queued_spin_lock_slowpath+91
[IRQ stack]
native_queued_spin_lock_slowpath at ffffffffb814e30b
_raw_spin_lock at ffffffffb89a667a
lpfc_rx_monitor_record at ffffffffc0a73a36 [lpfc]
lpfc_cmf_timer at ffffffffc0abbc67 [lpfc]
__hrtimer_run_queues at ffffffffb8184250
hrtimer_interrupt at ffffffffb8184ab0
smp_apic_timer_interrupt at ffffffffb8a026ba
apic_timer_interrupt at ffffffffb8a01c4f
[End of IRQ stack]
apic_timer_interrupt at ffffffffb8a01c4f
lpfc_rx_monitor_report at ffffffffc0a73c80 [lpfc]
lpfc_rx_monitor_read at ffffffffc0addde1 [lpfc]
full_proxy_read at ffffffffb83e7fc3
vfs_read at ffffffffb833fe71
ksys_read at ffffffffb83402af
do_syscall_64 at ffffffffb800430b
entry_SYSCALL_64_after_hwframe at ffffffffb8a000ad |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: efct: Fix possible memleak in efct_device_init()
In efct_device_init(), when efct_scsi_reg_fc_transport() fails,
efct_scsi_tgt_driver_exit() is not called to release memory for
efct_scsi_tgt_driver_init() and causes memleak:
unreferenced object 0xffff8881020ce000 (size 2048):
comm "modprobe", pid 465, jiffies 4294928222 (age 55.872s)
backtrace:
[<0000000021a1ef1b>] kmalloc_trace+0x27/0x110
[<000000004c3ed51c>] target_register_template+0x4fd/0x7b0 [target_core_mod]
[<00000000f3393296>] efct_scsi_tgt_driver_init+0x18/0x50 [efct]
[<00000000115de533>] 0xffffffffc0d90011
[<00000000d608f646>] do_one_initcall+0xd0/0x4e0
[<0000000067828cf1>] do_init_module+0x1cc/0x6a0
... |
| In the Linux kernel, the following vulnerability has been resolved:
drm/sched: Fix deadlock in drm_sched_entity_kill_jobs_cb
The Mesa issue referenced below pointed out a possible deadlock:
[ 1231.611031] Possible interrupt unsafe locking scenario:
[ 1231.611033] CPU0 CPU1
[ 1231.611034] ---- ----
[ 1231.611035] lock(&xa->xa_lock#17);
[ 1231.611038] local_irq_disable();
[ 1231.611039] lock(&fence->lock);
[ 1231.611041] lock(&xa->xa_lock#17);
[ 1231.611044] <Interrupt>
[ 1231.611045] lock(&fence->lock);
[ 1231.611047]
*** DEADLOCK ***
In this example, CPU0 would be any function accessing job->dependencies
through the xa_* functions that don't disable interrupts (eg:
drm_sched_job_add_dependency(), drm_sched_entity_kill_jobs_cb()).
CPU1 is executing drm_sched_entity_kill_jobs_cb() as a fence signalling
callback so in an interrupt context. It will deadlock when trying to
grab the xa_lock which is already held by CPU0.
Replacing all xa_* usage by their xa_*_irq counterparts would fix
this issue, but Christian pointed out another issue: dma_fence_signal
takes fence.lock and so does dma_fence_add_callback.
dma_fence_signal() // locks f1.lock
-> drm_sched_entity_kill_jobs_cb()
-> foreach dependencies
-> dma_fence_add_callback() // locks f2.lock
This will deadlock if f1 and f2 share the same spinlock.
To fix both issues, the code iterating on dependencies and re-arming them
is moved out to drm_sched_entity_kill_jobs_work().
[phasta: commit message nits] |
| In the Linux kernel, the following vulnerability has been resolved:
bnxt_en: Shutdown FW DMA in bnxt_shutdown()
The netif_close() call in bnxt_shutdown() only stops packet DMA. There
may be FW DMA for trace logging (recently added) that will continue. If
we kexec to a new kernel, the DMA will corrupt memory in the new kernel.
Add bnxt_hwrm_func_drv_unrgtr() to unregister the driver from the FW.
This will stop the FW DMA. In case the call fails, call pcie_flr() to
reset the function and stop the DMA. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/gpusvm: fix hmm_pfn_to_map_order() usage
Handle the case where the hmm range partially covers a huge page (like
2M), otherwise we can potentially end up doing something nasty like
mapping memory which is outside the range, and maybe not even mapped by
the mm. Fix is based on the xe userptr code, which in a future patch
will directly use gpusvm, so needs alignment here.
v2:
- Add kernel-doc (Matt B)
- s/fls/ilog2/ (Thomas) |
| In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: Correctly handle Rx checksum offload errors
The stmmac_rx function would previously set skb->ip_summed to
CHECKSUM_UNNECESSARY if hardware checksum offload (CoE) was enabled
and the packet was of a known IP ethertype.
However, this logic failed to check if the hardware had actually
reported a checksum error. The hardware status, indicating a header or
payload checksum failure, was being ignored at this stage. This could
cause corrupt packets to be passed up the network stack as valid.
This patch corrects the logic by checking the `csum_none` status flag,
which is set when the hardware reports a checksum error. If this flag
is set, skb->ip_summed is now correctly set to CHECKSUM_NONE,
ensuring the kernel's network stack will perform its own validation and
properly handle the corrupt packet. |
| In the Linux kernel, the following vulnerability has been resolved:
futex: Don't leak robust_list pointer on exec race
sys_get_robust_list() and compat_get_robust_list() use ptrace_may_access()
to check if the calling task is allowed to access another task's
robust_list pointer. This check is racy against a concurrent exec() in the
target process.
During exec(), a task may transition from a non-privileged binary to a
privileged one (e.g., setuid binary) and its credentials/memory mappings
may change. If get_robust_list() performs ptrace_may_access() before
this transition, it may erroneously allow access to sensitive information
after the target becomes privileged.
A racy access allows an attacker to exploit a window during which
ptrace_may_access() passes before a target process transitions to a
privileged state via exec().
For example, consider a non-privileged task T that is about to execute a
setuid-root binary. An attacker task A calls get_robust_list(T) while T
is still unprivileged. Since ptrace_may_access() checks permissions
based on current credentials, it succeeds. However, if T begins exec
immediately afterwards, it becomes privileged and may change its memory
mappings. Because get_robust_list() proceeds to access T->robust_list
without synchronizing with exec() it may read user-space pointers from a
now-privileged process.
This violates the intended post-exec access restrictions and could
expose sensitive memory addresses or be used as a primitive in a larger
exploit chain. Consequently, the race can lead to unauthorized
disclosure of information across privilege boundaries and poses a
potential security risk.
Take a read lock on signal->exec_update_lock prior to invoking
ptrace_may_access() and accessing the robust_list/compat_robust_list.
This ensures that the target task's exec state remains stable during the
check, allowing for consistent and synchronized validation of
credentials. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: pv: fix index value of replaced ASCE
The index field of the struct page corresponding to a guest ASCE should
be 0. When replacing the ASCE in s390_replace_asce(), the index of the
new ASCE should also be set to 0.
Having the wrong index might lead to the wrong addresses being passed
around when notifying pte invalidations, and eventually to validity
intercepts (VM crash) if the prefix gets unmapped and the notifier gets
called with the wrong address. |
| In the Linux kernel, the following vulnerability has been resolved:
media: dvb-usb: m920x: Fix a potential memory leak in m920x_i2c_xfer()
'read' is freed when it is known to be NULL, but not when a read error
occurs.
Revert the logic to avoid a small leak, should a m920x_read() call fail. |
| In the Linux kernel, the following vulnerability has been resolved:
ima: don't clear IMA_DIGSIG flag when setting or removing non-IMA xattr
Currently when both IMA and EVM are in fix mode, the IMA signature will
be reset to IMA hash if a program first stores IMA signature in
security.ima and then writes/removes some other security xattr for the
file.
For example, on Fedora, after booting the kernel with "ima_appraise=fix
evm=fix ima_policy=appraise_tcb" and installing rpm-plugin-ima,
installing/reinstalling a package will not make good reference IMA
signature generated. Instead IMA hash is generated,
# getfattr -m - -d -e hex /usr/bin/bash
# file: usr/bin/bash
security.ima=0x0404...
This happens because when setting security.selinux, the IMA_DIGSIG flag
that had been set early was cleared. As a result, IMA hash is generated
when the file is closed.
Similarly, IMA signature can be cleared on file close after removing
security xattr like security.evm or setting/removing ACL.
Prevent replacing the IMA file signature with a file hash, by preventing
the IMA_DIGSIG flag from being reset.
Here's a minimal C reproducer which sets security.selinux as the last
step which can also replaced by removing security.evm or setting ACL,
#include <stdio.h>
#include <sys/xattr.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
int main() {
const char* file_path = "/usr/sbin/test_binary";
const char* hex_string = "030204d33204490066306402304";
int length = strlen(hex_string);
char* ima_attr_value;
int fd;
fd = open(file_path, O_WRONLY|O_CREAT|O_EXCL, 0644);
if (fd == -1) {
perror("Error opening file");
return 1;
}
ima_attr_value = (char*)malloc(length / 2 );
for (int i = 0, j = 0; i < length; i += 2, j++) {
sscanf(hex_string + i, "%2hhx", &ima_attr_value[j]);
}
if (fsetxattr(fd, "security.ima", ima_attr_value, length/2, 0) == -1) {
perror("Error setting extended attribute");
close(fd);
return 1;
}
const char* selinux_value= "system_u:object_r:bin_t:s0";
if (fsetxattr(fd, "security.selinux", selinux_value, strlen(selinux_value), 0) == -1) {
perror("Error setting extended attribute");
close(fd);
return 1;
}
close(fd);
return 0;
} |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/amd: Fix potential out-of-bounds read in iommu_mmio_show
In iommu_mmio_write(), it validates the user-provided offset with the
check: `iommu->dbg_mmio_offset > iommu->mmio_phys_end - 4`.
This assumes a 4-byte access. However, the corresponding
show handler, iommu_mmio_show(), uses readq() to perform an 8-byte
(64-bit) read.
If a user provides an offset equal to `mmio_phys_end - 4`, the check
passes, and will lead to a 4-byte out-of-bounds read.
Fix this by adjusting the boundary check to use sizeof(u64), which
corresponds to the size of the readq() operation. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/vgem-fence: Fix potential deadlock on release
A timer that expires a vgem fence automatically in 10 seconds is now
released with timer_delete_sync() from fence->ops.release() called on last
dma_fence_put(). In some scenarios, it can run in IRQ context, which is
not safe unless TIMER_IRQSAFE is used. One potentially risky scenario was
demonstrated in Intel DRM CI trybot, BAT run on machine bat-adlp-6, while
working on new IGT subtests syncobj_timeline@stress-* as user space
replacements of some problematic test cases of a dma-fence-chain selftest
[1].
[117.004338] ================================
[117.004340] WARNING: inconsistent lock state
[117.004342] 6.17.0-rc7-CI_DRM_17270-g7644974e648c+ #1 Tainted: G S U
[117.004346] --------------------------------
[117.004347] inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
[117.004349] swapper/0/0 [HC1[1]:SC1[1]:HE0:SE0] takes:
[117.004352] ffff888138f86aa8 ((&fence->timer)){?.-.}-{0:0}, at: __timer_delete_sync+0x4b/0x190
[117.004361] {HARDIRQ-ON-W} state was registered at:
[117.004363] lock_acquire+0xc4/0x2e0
[117.004366] call_timer_fn+0x80/0x2a0
[117.004368] __run_timers+0x231/0x310
[117.004370] run_timer_softirq+0x76/0xe0
[117.004372] handle_softirqs+0xd4/0x4d0
[117.004375] __irq_exit_rcu+0x13f/0x160
[117.004377] irq_exit_rcu+0xe/0x20
[117.004379] sysvec_apic_timer_interrupt+0xa0/0xc0
[117.004382] asm_sysvec_apic_timer_interrupt+0x1b/0x20
[117.004385] cpuidle_enter_state+0x12b/0x8a0
[117.004388] cpuidle_enter+0x2e/0x50
[117.004393] call_cpuidle+0x22/0x60
[117.004395] do_idle+0x1fd/0x260
[117.004398] cpu_startup_entry+0x29/0x30
[117.004401] start_secondary+0x12d/0x160
[117.004404] common_startup_64+0x13e/0x141
[117.004407] irq event stamp: 2282669
[117.004409] hardirqs last enabled at (2282668): [<ffffffff8289db71>] _raw_spin_unlock_irqrestore+0x51/0x80
[117.004414] hardirqs last disabled at (2282669): [<ffffffff82882021>] sysvec_irq_work+0x11/0xc0
[117.004419] softirqs last enabled at (2254702): [<ffffffff8289fd00>] __do_softirq+0x10/0x18
[117.004423] softirqs last disabled at (2254725): [<ffffffff813d4ddf>] __irq_exit_rcu+0x13f/0x160
[117.004426]
other info that might help us debug this:
[117.004429] Possible unsafe locking scenario:
[117.004432] CPU0
[117.004433] ----
[117.004434] lock((&fence->timer));
[117.004436] <Interrupt>
[117.004438] lock((&fence->timer));
[117.004440]
*** DEADLOCK ***
[117.004443] 1 lock held by swapper/0/0:
[117.004445] #0: ffffc90000003d50 ((&fence->timer)){?.-.}-{0:0}, at: call_timer_fn+0x7a/0x2a0
[117.004450]
stack backtrace:
[117.004453] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G S U 6.17.0-rc7-CI_DRM_17270-g7644974e648c+ #1 PREEMPT(voluntary)
[117.004455] Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER
[117.004455] Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-P DDR4 RVP, BIOS RPLPFWI1.R00.4035.A00.2301200723 01/20/2023
[117.004456] Call Trace:
[117.004456] <IRQ>
[117.004457] dump_stack_lvl+0x91/0xf0
[117.004460] dump_stack+0x10/0x20
[117.004461] print_usage_bug.part.0+0x260/0x360
[117.004463] mark_lock+0x76e/0x9c0
[117.004465] ? register_lock_class+0x48/0x4a0
[117.004467] __lock_acquire+0xbc3/0x2860
[117.004469] lock_acquire+0xc4/0x2e0
[117.004470] ? __timer_delete_sync+0x4b/0x190
[117.004472] ? __timer_delete_sync+0x4b/0x190
[117.004473] __timer_delete_sync+0x68/0x190
[117.004474] ? __timer_delete_sync+0x4b/0x190
[117.004475] timer_delete_sync+0x10/0x20
[117.004476] vgem_fence_release+0x19/0x30 [vgem]
[117.004478] dma_fence_release+0xc1/0x3b0
[117.004480] ? dma_fence_release+0xa1/0x3b0
[117.004481] dma_fence_chain_release+0xe7/0x130
[117.004483] dma_fence_release+0xc1/0x3b0
[117.004484] ? _raw_spin_unlock_irqrestore+0x27/0x80
[117.004485] dma_fence_chain_irq_work+0x59/0x80
[117.004487] irq_work_single+0x75/0xa0
[117.004490] irq_work_r
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
block: Use RCU in blk_mq_[un]quiesce_tagset() instead of set->tag_list_lock
blk_mq_{add,del}_queue_tag_set() functions add and remove queues from
tagset, the functions make sure that tagset and queues are marked as
shared when two or more queues are attached to the same tagset.
Initially a tagset starts as unshared and when the number of added
queues reaches two, blk_mq_add_queue_tag_set() marks it as shared along
with all the queues attached to it. When the number of attached queues
drops to 1 blk_mq_del_queue_tag_set() need to mark both the tagset and
the remaining queues as unshared.
Both functions need to freeze current queues in tagset before setting on
unsetting BLK_MQ_F_TAG_QUEUE_SHARED flag. While doing so, both functions
hold set->tag_list_lock mutex, which makes sense as we do not want
queues to be added or deleted in the process. This used to work fine
until commit 98d81f0df70c ("nvme: use blk_mq_[un]quiesce_tagset")
made the nvme driver quiesce tagset instead of quiscing individual
queues. blk_mq_quiesce_tagset() does the job and quiesce the queues in
set->tag_list while holding set->tag_list_lock also.
This results in deadlock between two threads with these stacktraces:
__schedule+0x47c/0xbb0
? timerqueue_add+0x66/0xb0
schedule+0x1c/0xa0
schedule_preempt_disabled+0xa/0x10
__mutex_lock.constprop.0+0x271/0x600
blk_mq_quiesce_tagset+0x25/0xc0
nvme_dev_disable+0x9c/0x250
nvme_timeout+0x1fc/0x520
blk_mq_handle_expired+0x5c/0x90
bt_iter+0x7e/0x90
blk_mq_queue_tag_busy_iter+0x27e/0x550
? __blk_mq_complete_request_remote+0x10/0x10
? __blk_mq_complete_request_remote+0x10/0x10
? __call_rcu_common.constprop.0+0x1c0/0x210
blk_mq_timeout_work+0x12d/0x170
process_one_work+0x12e/0x2d0
worker_thread+0x288/0x3a0
? rescuer_thread+0x480/0x480
kthread+0xb8/0xe0
? kthread_park+0x80/0x80
ret_from_fork+0x2d/0x50
? kthread_park+0x80/0x80
ret_from_fork_asm+0x11/0x20
__schedule+0x47c/0xbb0
? xas_find+0x161/0x1a0
schedule+0x1c/0xa0
blk_mq_freeze_queue_wait+0x3d/0x70
? destroy_sched_domains_rcu+0x30/0x30
blk_mq_update_tag_set_shared+0x44/0x80
blk_mq_exit_queue+0x141/0x150
del_gendisk+0x25a/0x2d0
nvme_ns_remove+0xc9/0x170
nvme_remove_namespaces+0xc7/0x100
nvme_remove+0x62/0x150
pci_device_remove+0x23/0x60
device_release_driver_internal+0x159/0x200
unbind_store+0x99/0xa0
kernfs_fop_write_iter+0x112/0x1e0
vfs_write+0x2b1/0x3d0
ksys_write+0x4e/0xb0
do_syscall_64+0x5b/0x160
entry_SYSCALL_64_after_hwframe+0x4b/0x53
The top stacktrace is showing nvme_timeout() called to handle nvme
command timeout. timeout handler is trying to disable the controller and
as a first step, it needs to blk_mq_quiesce_tagset() to tell blk-mq not
to call queue callback handlers. The thread is stuck waiting for
set->tag_list_lock as it tries to walk the queues in set->tag_list.
The lock is held by the second thread in the bottom stack which is
waiting for one of queues to be frozen. The queue usage counter will
drop to zero after nvme_timeout() finishes, and this will not happen
because the thread will wait for this mutex forever.
Given that [un]quiescing queue is an operation that does not need to
sleep, update blk_mq_[un]quiesce_tagset() to use RCU instead of taking
set->tag_list_lock, update blk_mq_{add,del}_queue_tag_set() to use RCU
safe list operations. Also, delete INIT_LIST_HEAD(&q->tag_set_list)
in blk_mq_del_queue_tag_set() because we can not re-initialize it while
the list is being traversed under RCU. The deleted queue will not be
added/deleted to/from a tagset and it will be freed in blk_free_queue()
after the end of RCU grace period. |
