| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
l2tp: use refcount_inc_not_zero in l2tp_session_get_by_ifname
A reader in l2tp_session_get_by_ifname() can return a pointer to a
session whose refcount has reached zero. The getter takes its
reference with plain refcount_inc(), but every other session getter
in the same file (l2tp_v2_session_get, l2tp_v3_session_get, and the
corresponding _get_next variants) uses refcount_inc_not_zero()
because the IDR/RCU lookup can race with refcount_dec_and_test() ->
l2tp_session_free() -> kfree_rcu(). The ifname getter is the only
outlier; the inconsistency was raised on-list after 979c017803c4
("l2tp: use list_del_rcu in l2tp_session_unhash").
A reader inside rcu_read_lock_bh() that matches session->ifname can
be preempted between the strcmp() and the refcount_inc(). If the
last reference drops on another CPU in that window, the reader's
refcount_inc() runs on a counter that has reached zero. refcount_t
catches the addition-on-zero, prints "refcount_t: addition on 0;
use-after-free", saturates the counter, and returns the saturated
pointer to the caller. Session memory is held live by the in-flight
RCU read section, but the kfree_rcu() callback queued from
l2tp_session_free() will free it once the grace period closes; a
caller that dereferences the returned session past that point hits
a slab-use-after-free. On PREEMPT_RT local_bh_disable() is a per-CPU
sleeping lock and the preemption window is real; on stock PREEMPT
kernels local_bh_disable() is a preempt_count increment that closes
the cross-CPU race in practice (see below).
Use refcount_inc_not_zero() and continue the list walk on failure,
matching the other session getters in the file. The ifname getter
is the only session getter in net/l2tp/ that still uses the bare
refcount_inc() pattern; this change restores file-internal
consistency. The success path is unchanged. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: fix chan ref leak in l2cap_chan_timeout() on !conn
__set_chan_timer() takes a l2cap_chan reference via l2cap_chan_hold()
before scheduling the delayed work. The normal path in
l2cap_chan_timeout() drops this reference with l2cap_chan_put() at the
end, but the early return when chan->conn is NULL skips the put,
leaking the reference.
Add the missing l2cap_chan_put() before the early return. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/rmap: initialize nr_pages to 1 at loop start in try_to_unmap_one
Initialize nr_pages to 1 at the start of each loop iteration, like
folio_referenced_one() does.
Without this, nr_pages computed by a previous folio_unmap_pte_batch() call
can be reused on a later iteration that does not run
folio_unmap_pte_batch() again.
mmap a 64K large folio with MAP_ANONYMOUS | MAP_DROPPABLE, then call
madvise(MADV_FREE), then make the last page device-exclusive via
HMM_DMIRROR_EXCLUSIVE.
Trigger node reclaim through sysfs. Now, in try_to_unmap_one(), we will
first clear the first 15 out of 16 entries mapping the lazyfree folio.
This will set nr_pages to 15. In the next pvmw walk, this nr_pages gets
reused on a device-exclusive pte, thus potentially corrupting folio
refcount/mapcount.
At the moment, I have a userspace program which can make the kernel spit
out a trace, but the blow up is in folio_referenced_one(), because there
are existing bugs in the interaction between device-private and rmap
(which too I am investigating). I did a one liner kernel change to avoid
going into folio_referenced_one(), and the kernel blows up at
folio_remove_rmap_ptes in try_to_unmap_one which is what I wanted.
Note that the bug is there not since file folio batching but lazyfree
folio batching, since device-exclusive only works for anonymous folios.
Userspace visible effect is simply kernel crashing somewhere due to
refcount/mapcount corruption. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: don't drop the runtime PM reference twice in amdgpu_gpr
amdgpu_debugfs_gpr_read() drops its runtime PM reference right after
reading the wave registers. When copying them to userspace fails, it
jumps to the err label, which drops the reference a second time. A read
into a bad buffer on Navi31 either steals a reference somebody else
holds (power/runtime_usage goes from 1 to 0) or underflows the count:
amdgpu 0000:03:00.0: Runtime PM usage count underflow!
The registers are already in the kernel buffer at that point, so finish
the hardware access first and copy the buffer with a single
copy_to_user() instead of the put_user() loop with its own error path.
(cherry picked from commit 31035bbd74f7c3e10c163db875b8e67f8b50ee6a) |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: samsung: i2s: enable op_clk in probe to balance runtime PM
The probe function puts the device into the runtime PM active state with
only the "iis" bus clock enabled, but it also sets priv->op_clk to the
parent of the RCLK_SRC mux without enabling it. The runtime PM suspend
callback disables both clocks, so the first runtime suspend after probe
disables op_clk once more than it was enabled.
On Exynos5250 Arndale both clocks resolve to the same EXYNOS_I2S_BUS gate,
so this triggers the following warning during boot:
WARNING: drivers/clk/clk.c:1270 at clk_core_disable+0xe4/0x23c, CPU#0: kworker/u8:3/45
i2s_bus already disabled
...
Workqueue: pm pm_runtime_work
Call trace:
...
clk_core_disable from clk_disable+0x28/0x34
clk_disable from i2s_runtime_suspend+0x58/0x68 [snd_soc_i2s]
i2s_runtime_suspend [snd_soc_i2s] from genpd_runtime_suspend+0xc4/0x298
genpd_runtime_suspend from __rpm_callback+0x48/0x18c
__rpm_callback from rpm_callback+0x4c/0x50
rpm_callback from rpm_suspend+0xf4/0x718
rpm_suspend from pm_runtime_work+0x9c/0xa0
...
Fix this by enabling op_clk in probe right after getting it, so the clock
state matches the runtime PM active state, and by disabling it in remove. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: scrub: fix local_root reference leak in scrub_print_warning_inode()
When paths_from_inode() fails, scrub_print_warning_inode() jumps to err
without dropping the reference taken by btrfs_get_fs_root(), leaking a
reference to the root every time path resolution fails while printing
scrub warnings. Every other error and success path of the function
drops the reference.
Drop the reference on the paths_from_inode() failure path too. |
| In the Linux kernel, the following vulnerability has been resolved:
gpio: xilinx: fix runtime PM leak on request error path
pm_runtime_get_sync() leaves the usage counter incremented even when it
fails, and xgpio_request() returns the error without dropping it.
gpiolib does not call ->free() when ->request() fails, so xgpio_free(),
which holds the only matching pm_runtime_put(), never runs. The reference
is leaked and the controller can no longer runtime-suspend, so its clock
stays enabled.
Switch to pm_runtime_resume_and_get(), which only increments the usage
counter on success. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: ch: Do not keep references to data transfer element devices
ch_readconfig() looks up the scsi_device of every data transfer element
whose SCSI id the changer reports in READ ELEMENT STATUS, and stores it in
ch->dt[]. scsi_device_lookup() takes a reference, and nothing ever drops
it: ch_destroy() frees the array with kfree(). ch->dt[] is read nowhere
else - it only supplies the vendor, model and revision printed in the same
loop.
Once such a drive is removed, its scsi_device can never be released. It
stays on the host's device list at its address, so a new device there is
refused by anything that walks the list - target_core_pscsi reports
"scsi_device_get() failed for H:C:T:L" - and the low-level driver's module
can no longer be unloaded. Only a reboot recovers.
It shows with any changer that reports its drives' ids; with the mhvtl
virtual library (IBM 3573-TL personality), each create and remove of a
library with four drives leaves four references behind, counted by the
module's use count in lsmod. With ch not bound the count is unchanged, and
with this patch applied it is unchanged too.
Drop the reference as soon as the name has been printed, and remove the now
unused dt[] array. That also removes the array leaked when ch_probe() fails
after ch_readconfig().
The same leak was reported with an RFC patch in 2022, which was not merged. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_flow_offload: drop flowtable reference on init error path
nft_flow_offload_init() bumps the flowtable use count with
nft_use_inc() before calling nf_ct_netns_get(). When the latter
fails, the error is returned as-is and the reference is leaked.
The upper layers do not balance it either: nf_tables_newexpr()
clears expr->ops when the expression init callback fails, so the
nft_expr_more() iteration in nft_rule_expr_deactivate() and
nf_tables_rule_destroy() stops right before the failed expression
and its ->destroy callback, which would drop the reference, never
runs.
Each failed rule addition therefore leaks one flowtable reference
and the flowtable can no longer be removed: NFT_MSG_DELFLOWTABLE
keeps reporting -EBUSY even though no rule references it.
Save the nf_ct_netns_get() return value and undo the nft_use_inc()
when it fails, restoring the inc/dec pairing within
nft_flow_offload_init() itself. |
| In the Linux kernel, the following vulnerability has been resolved:
iio: accel: kxcjk-1013: reject duplicate event disable
The IIO core does not filter duplicate writes to the event enable
attribute. kxcjk1013_write_event_config() already ignores repeated
enable requests, but a repeated disable request still calls
kxcjk1013_set_power_state(data, false), dropping a runtime PM reference
that was not acquired for this request. This can underflow the runtime
PM usage count and trigger a "Runtime PM usage count underflow" warning.
Return early when the requested state already matches ev_enable_state. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: Fix runtime PM leak in amdgpu_debugfs_test_ib_show()
amdgpu_debugfs_test_ib_show() resumes the device with
pm_runtime_get_sync() before taking the reset domain semaphore with
down_write_killable(). If the write lock acquisition is interrupted,
the function returns without calling pm_runtime_put_autosuspend(),
leaking the runtime PM reference acquired for the device and keeping
the GPU awake.
Drop the runtime PM reference on the interrupted down_write_killable()
error path before returning.
(cherry picked from commit ec30a576c2d4c0364549e6c04218f50704ef56c8) |
| In the Linux kernel, the following vulnerability has been resolved:
drm/nouveau: don't bump pin count on failed re-pin in nouveau_bo_pin_locked()
nouveau_bo_pin_locked() checks whether an already pinned BO is in a
memory domain compatible with a new pin request. When the domains are
incompatible, it sets -EBUSY but still calls ttm_bo_pin() before
returning.
Callers treat a failed nouveau_bo_pin() as not having acquired a new pin,
so the extra pin count is never decreased by a matching unpin.
This triggers the warning in ttm_bo_release():
WARN_ON_ONCE(bo->pin_count);
Found when fuzzing the nouveau driver with a modified Syzkaller:
WARNING: drivers/gpu/drm/ttm/ttm_bo.c:256 at ttm_bo_release+0x827/0x9e0 drivers/gpu/drm/ttm/ttm_bo.c:256, CPU#1: syz.3.24/2212
Modules linked in:
CPU: 1 UID: 0 PID: 2212 Comm: syz.3.24 Not tainted 7.2.0 #24 PREEMPT(lazy)
nouveau 0000:01:00.0: gsp:msg fn:103 len:0x40/0x20 res:0x19 resp:0x19
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:ttm_bo_release+0x827/0x9e0 drivers/gpu/drm/ttm/ttm_bo.c:256
Code: 02 00 0f 85 51 01 00 00 48 8b 7b 08 e8 d2 20 01 00 e9 80 fd ff ff e8 d8 15 c0 fe 90 0f 0b 90 e9 e1 f8 ff ff e8 ca 15 c0 fe 90 <0f> 0b 90 e9 a4 f8 ff ff e8 bc 15 c0 fe be 03 00 00 00 4c 89 e7 e8
msg: 00000000: 05 00 d0 c1 04 00 f0 f1 01 30 00 00 2d 90 00 00 .........0..-...
RSP: 0018:ffffc9000f5cf710 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888018e5d2a8 RCX: ffffffff82bb1b36
RDX: ffff888017b68000 RSI: 0000000000000004 RDI: ffff888018e5d2a8
msg: 00000010: 19 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
RBP: ffff88801261c720 R08: 0000000000000001 R09: ffffed10031cba55
R10: ffff888018e5d2ab R11: 00000000000000f3 R12: ffff888018e5d290
R13: ffff888018e5d2d4 R14: ffff88801b219c18 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880e0f6f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31223ffc CR3: 0000000028e00005 CR4: 0000000000770ef0
PKRU: 80000000
Call Trace:
<TASK>
kref_put include/linux/kref.h:65 [inline]
ttm_bo_put drivers/gpu/drm/ttm/ttm_bo.c:325 [inline]
ttm_bo_fini+0x55/0x80 drivers/gpu/drm/ttm/ttm_bo.c:330
nouveau_gem_object_del+0xb2/0x1b0 drivers/gpu/drm/nouveau/nouveau_gem.c:90
drm_gem_object_free+0x5f/0x90 drivers/gpu/drm/drm_gem.c:1165
kref_put include/linux/kref.h:65 [inline]
__drm_gem_object_put include/drm/drm_gem.h:562 [inline]
drm_gem_object_put include/drm/drm_gem.h:575 [inline]
nouveau_abi16_chan_fini.constprop.0+0x44f/0x5a0 drivers/gpu/drm/nouveau/nouveau_abi16.c:195
nouveau 0000:01:00.0: syz.2.23[2209]: Unknown handle 0x00000000
nouveau_abi16_fini+0x1d0/0x340 drivers/gpu/drm/nouveau/nouveau_abi16.c:225
nouveau_drm_postclose+0x18b/0x3e0 drivers/gpu/drm/nouveau/nouveau_drm.c:1284
nouveau 0000:01:00.0: syz.2.23[2209]: validate_init
drm_file_free.part.0+0x6d6/0xb60 drivers/gpu/drm/drm_file.c:267
drm_file_free drivers/gpu/drm/drm_file.c:237 [inline]
drm_close_helper.isra.0+0x11a/0x160 drivers/gpu/drm/drm_file.c:290
drm_release+0x1ab/0x330 drivers/gpu/drm/drm_file.c:438
__fput+0x39c/0xa60 fs/file_table.c:512
nouveau 0000:01:00.0: syz.2.23[2209]: validate: -2
task_work_run+0x15a/0x230 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x82b/0x25a0 kernel/exit.c:1009
do_group_exit+0xc2/0x280 kernel/exit.c:1152
get_signal+0x1d6e/0x1f30 kernel/signal.c:3046
arch_do_signal_or_restart+0x7d/0x6e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0xdf/0x440 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x4f8/0x690 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RI
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix cifsFileInfo reference leak in deferred close
When cifs_close() defers a close, it hands the cifsFileInfo reference
of the closing struct file to the queued work. Each execution of
smb2_deferred_work_close() drops one such reference.
deferred_close_scheduled can be false while the work is pending: the
workqueue clears PENDING when the callback starts to run, before the
callback clears the flag under deferred_lock. A close in that
interval requeues the running work, and the callback then clears the
flag, leaving the requeued work pending with the flag down. A later
cifs_open() can reuse the handle and its cifs_close() reaches the
same branch: queue_delayed_work() fails because the work is still
pending, but cifs_close() returns without dropping the closing file's
reference. The cifsFileInfo count stays pinned and its tlink, dentry
and server handle are leaked.
Check the return value and hand off the reference only when work was
actually queued. Otherwise, use the shared _cifsFileInfo_put(), like
the mod_delayed_work() branch above: the pending execution already
owns its reference.
This issue was found by an in-house static analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: avoid leaking refcount in cifs_queue_oplock_break()
cifs_queue_oplock_break() unconditionally takes a reference on the
target file before queueing cifs_oplock_break(). Only that work item
decreases the reference counter again.
If another oplock break arrives while that work is still queued,
queue_work() will return false and not queue this second work item. As a
result, we will never reach the point to drop the file reference again
and are leaking this reference. This can be triggered when interacting
with a slow-responding server.
As a result, later unmount operations for this file system will fail with
BUG: Dentry ... still in use (1) [unmount of cifs cifs]
VFS: Busy inodes after unmount of cifs (cifs)
kernel BUG at fs/super.c:777!
Fix this by only incrementing the reference count if the work has been
queued successfully. Taking it after queue_work() is safe because all
three callers hold tcon->open_file_lock across the call and
_cifsFileInfo_put() decrements under that same lock, so a worker that
starts the handler in the window cannot drop the reference before it has
been taken. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: avoid leaking refcount when cifs_sb_tlink() fails
cifs_oplock_break() takes over the reference that
cifs_queue_oplock_break() acquired when it queued the work, and drops it
with _cifsFileInfo_put() once the break has been processed.
Only in setups with "-o multiuser", cifs_sb_tlink() may fail, at which
point cifs_oplock_break() returns without putting the file reference,
mirroring the reference leak we already fixed in the companion patch to
cifs_queue_oplock_break().
This would trigger a crash due to busy inodes on the next unmount:
BUG: Dentry ... still in use (1) [unmount of cifs cifs]
VFS: Busy inodes after unmount of cifs (cifs)
Drop the reference on that path as well. Doing so before the out label
mirrors the normal path, which also puts the reference before
cifs_done_oplock_break().
Found by Sashiko code review. The failure path was not exercised at
runtime. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/counter: Fix num_counters leak on bind_qp failure in alloc_and_bind()
When __rdma_counter_bind_qp() fails in alloc_and_bind(), the error path
jumps to err_mode which frees the counter without decrementing
port_counter->num_counters. The only place that decrements is
rdma_counter_free(), which is unreachable since the counter was never
successfully bound.
This leak accumulates across repeated failures, permanently preventing
the port from switching to AUTO mode (-EBUSY in __counter_set_mode())
and blocking the MANUAL→NONE auto-revert in rdma_counter_free(). When
the mode was NONE before the call, the MANUAL mode set by
__counter_set_mode() also leaks since the revert logic is never
reached.
Add an err_bind label between the num_counters increment and the
existing err_mode label. It decrements num_counters and mirrors the
MANUAL→NONE revert from rdma_counter_free(), ensuring the port state
is fully restored on bind failure. |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: hdac_hda: Fix hlink refcount leak on component registration failure
hdac_hda_dev_probe() gets the HDA link with snd_hdac_ext_bus_link_get()
before registering the ASoC component. If component registration fails,
the function returns without dropping the link reference.
Always call snd_hdac_ext_bus_link_put() after the registration attempt so
the reference taken during probe is balanced on both success and failure. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/mglru: fix and remove redundant unevictable folio handling
sort_folio() has a shortcut for moving folios that are no longer evictable
but are still sitting on a generation list. However, this shortcut is
buggy. It does not follow the PG_lru usage convention, and it has a more
serious issue.
Unevictable folios are not threaded on lists[LRU_UNEVICTABLE], so that
folio->lru can be reused to hold folio->mlock_count (see the comment in
lruvec_init()). Hence lruvec_add_folio() skips the list_add() for them,
and every other place that turns a folio unevictable initialises
mlock_count explicitly: lru_add() sets it to 0, __mlock_folio() and
__mlock_new_folio() set it to !!folio_test_mlocked(folio). sort_folio()
sets nothing, and the lru_gen_del_folio() right above it may have already
poisoned folio->lru via list_del(), so mlock_count ends up aliasing
LIST_POISON2, which reads as 0x122, i.e. 290. The result is user
visible. On munlock, __munlock_folio() decrements that bogus count, finds
it still non-zero and bails out before clearing PG_mlocked, so the folio
remains unevictable and the Mlocked accounting stays inflated until the
folio is freed.
The shortcut also touches the LRU flags in the wrong order. It calls
lru_gen_del_folio() while PG_lru is still set, so a concurrent
folio_test_clear_lru() (e.g. compaction, folio_isolate_lru()) can succeed
on a folio that has already been taken off the generation list, which may
lead to unexpected behavior.
So fix it by isolating them as common folios and letting the generic
shrink path cull them. This matches the classical LRU behavior, and there
should be no visible effect on the generic eviction or isolation behavior.
There is no performance concern either, such a folio goes through this
once, and then it is off the generation lists for good. |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: release path refs on follow_down() error
nfsd_cross_mnt() initializes a local struct path with mntget() and
dget() before calling follow_down(). On a negative return the error
arm jumps to out without releasing those references:
err = follow_down(&path, follow_flags);
if (err < 0)
goto out;
follow_down() never drops the caller's entry-time refs on any error
sub-case; for example a pre-cross d_manage() failure leaves path
untouched, so the mntget()/dget() taken on entry survive the call.
Every other early-exit arm in nfsd_cross_mnt() (other-namespace
return, IS_ERR(exp2), and the success tail after the swap) already
calls path_put(&path); the err < 0 arm is the lone omission. The
leak inflates mnt_count and d_count on each failed cross-mount,
blocking umount and pinning dentries against the shrinker, and is
reachable by any authenticated NFS client through nfsd_lookup_dentry
or the NFSv4 READDIR encode path.
Fix by calling path_put(&path) before the goto out in the err < 0
arm so the entry-time refs are released on all follow_down() error
returns. |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix nfsd_file leak on inter-server COPY setup failure
When nfsd4_setup_inter_ssc() fails, nfsd4_copy() returns
nfserr_offload_denied directly, bypassing the out: label where
release_copy_files() would drop the nf_dst reference taken by
nfs4_preprocess_stateid_op(). Each failed inter-server COPY
leaks one nfsd_file, pinning file/inode/dentry/vfsmount.
Fix by setting status and jumping to out: instead of returning
directly. |
