| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
fs: fix user path of nested backing files
backing_file_open() derives the path to be stored in the new backing
file from user_file->f_path. This is incorrect when user_file itself
is a backing file, which is the case for nested stacking filesystems,
e.g. overlayfs mounts where the lowerdir of one overlayfs is the merged
directory of another. Since commit def3ae83da02 ("fs: store real path
instead of fake path in backing file f_path") the f_path of a backing
file holds the real path of the intermediate layer, not the path that
the user opened.
Commit 924577e4f6ca ("ovl: Fix nested backing file paths") fixed this
for such configurations by passing file_user_path() from
ovl_open_realfile(). However, commit 6af36aeb147a ("lsm: add
backing_file LSM hooks") changed the first argument of
backing_file_open() from the user path back to the user file and
derived the path from user_file->f_path again, silently re-introducing
the problem.
As a result, files mapped through a nested overlayfs show the wrong
path in /proc/<pid>/maps and in perf/ftrace mmap records. For example,
with two nested overlayfs mounts:
mkdir -p /ovl/{lower,upper,work,merged} /ovl/nested
echo hello > /ovl/lower/foo
mount -t overlay overlay \
-o lowerdir=/ovl/lower,upperdir=/ovl/upper,workdir=/ovl/work \
/ovl/merged
# at least two lowerdirs are needed when upperdir is nonexistent
mount -t overlay overlay \
-o lowerdir=/ovl/merged:/ovl/lower /ovl/nested
mapping /ovl/nested/foo shows a disconnected path instead of the user
path:
# readlink /proc/self/fd/3
/ovl/nested/foo
# grep foo /proc/self/maps
7f6e2c100000-7f6e2c101000 r--s 00000000 00:24 15813027 /foo
The bogus path is derived from the f_path of the intermediate backing
file, whose mount is a private clone that d_path() cannot resolve.
Fix this by using file_user_path(), which returns the outermost
user-visible path for backing files and falls back to
&user_file->f_path for regular files. This restores the behavior of
commit 924577e4f6ca ("ovl: Fix nested backing file paths") for
overlayfs and also fixes the same problem for the other
backing_file_open() callers, fuse passthrough and erofs ishare, when
their user file is itself a backing file.
backing_tmpfile_open() has the same pattern but is not affected: it is
only called by ovl_create_tmpfile() for the upper layer, and another
overlayfs is rejected as upperdir by the DCACHE_OP_REAL check in
ovl_mount_dir_check(), so its user_file can never be a backing file. |
| In the Linux kernel, the following vulnerability has been resolved:
pidfd: hold exec_update_lock around namespace ioctl
The PIDFD_GET_*_NAMESPACE ioctls in pidfd_ioctl() perform a filesystem
credentials ptrace access check before handing out a namespace file
descriptor. The accompanying comment states that the code "mirrors nsfs
behavior", but, unlike the corresponding procfs paths, it does so without
holding the target task's exec_update_lock.
proc_ns_get_link() and proc_ns_readlink() both take exec_update_lock for
reading around the ptrace check and the namespace lookup, so that the
credentials used for the access decision match those of the task when its
namespace is read. Without it, a caller can pass the check against the
target's old credentials and then read the namespace after the target has
execve()'d a setuid binary and committed new credentials -- accessing
namespace information it should have been denied.
Hold exec_update_lock for reading around the ptrace check and the
namespace lookup so that pidfd truly mirrors nsfs behavior, as the comment
already claims. open_namespace() itself runs outside the lock: once a
namespace reference is obtained it carries its own refcount and is opened
with the caller's own credentials, so a concurrent execve() on the target
can no longer affect the outcome. |
| 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:
usb: typec: thunderbolt: Disable work before freeing tbt on remove
tbt_altmode_remove() drops the plug and cable references without
draining tbt->work. The work function dereferences those references,
and can also requeue itself in its error path. The VDM callbacks can
queue the same work item.
Disable and drain tbt->work before dropping the references. This waits
for an existing invocation and prevents subsequent schedule_work()
calls from queueing it during teardown.
This issue was found by an in-house static analysis tool and confirmed
by manual code review. |
| In the Linux kernel, the following vulnerability has been resolved:
PCI/sysfs: Fix out-of-bounds read in pci_write_legacy_io()
pci_write_legacy_io() loads 4 bytes from the kernfs write buffer
regardless of how many bytes userspace wrote:
if (count != 1 && count != 2 && count != 4)
return -EINVAL;
return pci_legacy_write(bus, off, *(u32 *)buf, count);
kernfs_fop_write_iter() allocates the buffer with kmalloc(len + 1),
so a 1-byte write to the legacy_io sysfs file allocates 2 bytes and
the unconditional u32 load reads up to 2 bytes past the end of the
allocation, which KASAN reports as a slab-out-of-bounds read.
Similarly, a 2-byte write overreads by 1 byte.
Thus, read only the number of bytes requested using get_unaligned_le16()
and get_unaligned_le32() for the 2 and 4 byte cases, interpreting the
buffer as little-endian to match the byte ordering of PCI I/O port
space.
The PowerPC implementation previously compensated for the generic
code's native-endian 32-bit load by shifting the value into place
for the 1 and 2 byte cases. The shifts were only correct on
big-endian kernels.
On little-endian PowerPC (POWER8 and later), they extracted the wrong
bytes, so a 1-byte write wrote an out-of-bounds byte instead of the
requested value. On big-endian, the native load also caused out_le16()
and out_le32() to reverse the user's bytes on the wire for 2 and 4 byte
writes. The little-endian helpers resolve both issues, so the shifts
are removed.
No changes are needed for the Alpha platform.
The legacy_io file is root-only and exists only on Alpha and PowerPC,
the two architectures that define HAVE_PCI_LEGACY. |
| In the Linux kernel, the following vulnerability has been resolved:
phy: rockchip-samsung-dcphy: fix out-of-range max_register
The PHY register block is 64KB, so with a register stride of 4 the
last accessible register sits at offset 0xfffc. max_register names
0x10000, one register past the end of the mapping: dumping the
registers through the regmap debugfs interface reads beyond the
ioremapped region and oopses on the unmapped page. The oops fires
with the regmap lock held, so later PHY operations deadlock. |
| In the Linux kernel, the following vulnerability has been resolved:
zram: fix out-of-bounds access in read_block_state()
read_block_state() calculates nr_pages before taking dev_lock. If the
device is reset and reinitialized with a smaller disksize before lock
acquisition, nr_pages still describes the old table. The subsequent loop
can then call slot_lock() past the end of the newly allocated table.
Read disksize after acquiring dev_lock and checking that the device is
initialized. The read lock then keeps the table and its bound stable for
the duration of the scan. |
| In the Linux kernel, the following vulnerability has been resolved:
zram: set default primary compressor in zram_destroy_comps()
Patch series "zram: fix zram issues reported by sashiko".
Sashiko drove by and reported [1] a couple of zram issues:
a possible BUG_ON() in zlib code due to missing winbits range
validation and one possible NULL-ptr dereference in zcomp.
Both are low risk yet still worth fixing.
This patch (of 2):
zram_destroy_comps() resets all compressors and leaves them set to NULL,
including the primary one, which is invalid device state, as now
comp_algorithm_show()->strcmp() can be called on a NULL compressor. Set
default primary compressor in zram_destroy_comps(). |
| In the Linux kernel, the following vulnerability has been resolved:
NFS: fix delegation_hash_table leak when nfs4_server_common_setup() fails
nfs4_server_common_setup() allocates server->delegation_hash_table
first, but server->destroy - the only path that frees the table via
nfs4_destroy_server() - is not assigned until the very end of the
function. If any intermediate step fails (the is_ds_only_client()
check, nfs4_init_session(), nfs4_get_rootfh(), or nfs_probe_server()),
the function returns with server->destroy still NULL, so the caller's
nfs_free_server() skips the destroy callback and the hash table is
leaked (4 KiB per attempt with the default delegation watermark).
This is trivially reachable from userspace: every failed NFSv4 mount
leaks one allocation. A client that persistently retries a mount that
cannot succeed leaks kernel memory without bound. Observed in
production where a Longhorn backup poller retried mount.nfs4 against
an NFSv3-only server roughly 10 times per second, leaking ~3.4 GiB of
unreclaimable slab (kmalloc-rnd-13-4k) per day; the node accumulated
12 GiB of leaked slab before the source was identified via the
kmem:kmalloc tracepoint (call_site=nfs4_delegation_hash_alloc).
Reproducer:
# server exports NFSv3 only (or export path absent for v4)
while :; do mount -t nfs4 <server>:/missing /mnt; done
# watch SUnreclaim in /proc/meminfo grow 4 KiB per iteration
Free the table on the error paths between the allocation and the
assignment of server->destroy. |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: validate nseconds in TIME_DELEG decode paths
The xdrgen-based TIME_DELEG_ACCESS and TIME_DELEG_MODIFY decode arms
store a raw uint32_t nseconds directly into tv_nsec without enforcing
nseconds < NSEC_PER_SEC. The legacy nfsd4_decode_nfstime4 has this
check but the TIME_DELEG paths do not. A malformed timespec can
propagate through notify_change() to disk.
Add range checks in both nfs4xdr.c (SETATTR path) and
nfs4callback.c (CB_GETATTR path). |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: widen nfsd_genl_rqstp address fields to sockaddr_storage
struct nfsd_genl_rqstp declares rq_daddr and rq_saddr as plain
"struct sockaddr" (16 bytes). When an IPv6 NFS client is connected,
nfsd_genl_rpc_status_compose_msg() casts these fields to
"struct sockaddr_in6 *" (28 bytes) and reads sin6_addr at offset 8..24,
which extends 8 bytes past the end of the 16-byte sockaddr field into
the adjacent rq_flags member. The 16-byte nla_put_in6_addr then ships 8
bytes of truncated IPv6 address followed by 8 bytes of rq_flags to
userspace via the NFSD_A_RPC_STATUS_SADDR6/DADDR6 netlink attributes.
This is reachable by any unprivileged process in the network namespace
because NFSD_CMD_RPC_STATUS_GET uses GENL_CMD_CAP_DUMP without
GENL_ADMIN_PERM.
Fix by widening rq_daddr and rq_saddr to struct sockaddr_storage so the
IPv6 casts operate within bounds, copying sizeof(struct sockaddr_storage)
bytes in the memcpy calls so the full address is captured, and
zero-initializing the genl_rqstp stack variable to prevent leaking
uninitialized tail bytes through netlink. |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: check nfsd4_acl_to_attr() return value in nfsd4_create()
nfsd4_create() stores the return value of nfsd4_acl_to_attr() in
status, but the switch(create->cr_type) block unconditionally
overwrites it in every branch. ACL translation errors are silently
discarded, and the CREATE proceeds without the requested ACL.
Add an early exit check after nfsd4_acl_to_attr(), matching the
pattern already used in nfsd4_setattr().
[ cel: prefer NFS4ERR_BADTYPE over NFS4ERR_ATTRNOTSUPP ] |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix dentry ref leak on V4ROOT export filehandle lookup
nfsd_set_fh_dentry() leaks the dentry reference from
exportfs_decode_fh_raw() when the NFS3_FHSIZE or NFS_FHSIZE
switch cases detect NFSEXP_V4ROOT and goto out. The out: label
calls exp_put() but never dput(dentry), and fhp->fh_dentry was
never assigned so fh_put() cannot compensate.
A crafted NFSv3 filehandle targeting a V4ROOT export's fsid
triggers the leak on every request. |
| In the Linux kernel, the following vulnerability has been resolved:
NFSD: Prevent post-shutdown use-after-free in unlock_filesystem
Writing a filesystem path to /proc/fs/nfsd/unlock_filesystem runs
nfsd4_cancel_copy_by_sb() before nfsd_mutex is held and before the
handler confirms that nn->nfsd_serv is set. Once nfsd has shut down,
nfs4_state_destroy_net() has freed nn->conf_id_hashtbl but left the
pointer intact, so the cancel helper iterates freed slab memory as an
array of struct list_head and then dereferences a bogus nfs4_client
when it takes clp->async_lock. A local administrator holding
CAP_SYS_ADMIN can reach this use-after-free by stopping the server and
then writing to unlock_filesystem; KASAN reports a slab-use-after-free
read in nfsd4_cancel_copy_by_sb().
nfsd4_revoke_states() walks the same state tables and for that reason
already runs only under nfsd_mutex with nn->nfsd_serv confirmed
present. Move the async COPY cancel into that protected section so
every NFSv4 state-table walker on this path observes a running server.
Async copies exist only while the server runs, so gating the cancel on
nn->nfsd_serv loses nothing. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: drop recovered reloc root refs on recovery failure
During relocation recovery, each fs root gets a reference to its relocation
root. If loading or adding a later root fails, or if the first transaction
commit fails, btrfs_recover_relocation() jumps to out_unset before
merge_reloc_roots() and clean_dirty_subvols().
put_reloc_control() drops the list-owned relocation root references, but it
does not clear fs_root->reloc_root or drop the references owned by those
pointers. Mount cleanup only drops them when BTRFS_FS_ERROR is set, so an
error such as -ENOMEM while processing a later root can leave references
behind.
Keep temporary references to the fs roots associated during recovery. On
failure, clear their reloc_root pointers and drop the corresponding
references. Once the first transaction commit succeeds, drop only the
temporary fs root references and let the normal merge and cleanup paths
handle the relocation roots.
Fault injection on a pending-relocation image confirmed the cleanup gap.
With an injected first-commit failure, 25 fs roots had reloc_root set with
fs_error=0. With this fix, the same failure path drops that count to 0
before mount fails. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix extent map leak in NOCOW direct I/O write
btrfs_dio_iomap_begin() calls btrfs_get_extent(), which returns an
extent map reference that must be dropped on all exit paths.
For direct writes into a NOCOW range, btrfs_get_blocks_direct_write()
keeps using that extent map and asks btrfs_create_dio_extent() to
allocate the ordered extent. If that fails, for example because
btrfs_alloc_ordered_extent() fails, the function returns the error
without dropping the input extent map. The PREALLOC path avoided this by
dropping the input extent map before replacing it with the newly created
one.
Check the error from btrfs_create_dio_extent() before replacing the
map and drop the input extent map on failure. |
| In the Linux kernel, the following vulnerability has been resolved:
cifs: call pagecache_isize_extended() in cifs_setsize() when extending
cifs_setsize() calls truncate_pagecache() but skips
pagecache_isize_extended() on extension. truncate_setsize() shows
the correct pattern:
i_size_write(inode, newsize);
if (newsize > oldsize)
pagecache_isize_extended(inode, oldsize, newsize);
truncate_pagecache(inode, newsize);
pagecache_isize_extended() zeroes the tail of the page straddling old
EOF. Without it, dirty bytes in that region can be written back to
the server, exposing stale data in the newly extended range. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: sony: fix UAF of ghl_poke_timer / ghl_urb at driver unbind
For GHL (Guitar Hero Live) dongles, sony_probe() arms a periodic timer:
ghl_magic_poke() (the timer callback) submits sc->ghl_urb, and the URB
completion ghl_magic_poke_cb() re-arms the timer with mod_timer().
sony_remove() drained the timer with timer_delete_sync() and then freed
the URB with usb_free_urb():
timer_delete_sync(&sc->ghl_poke_timer);
usb_free_urb(sc->ghl_urb);
timer_delete_sync() does not block re-arming, and while the URB is in
flight the timer is not pending, so the sync delete is a no-op. A URB
completion that runs after the delete re-arms the timer, and usb_free_urb()
only drops a reference -- it does not kill an in-flight URB. sc is
allocated with devm_kzalloc() and freed once sony_remove() returns, so the
re-armed ghl_poke_timer (embedded in sc) then fires on freed memory, a
use-after-free from timer softirq. This is a disconnect/rmmod race.
Poison the URB first, then shut the timer down, before freeing the URB.
usb_poison_urb() kills any in-flight URB and permanently rejects further
submissions, so a poke timer that is still pending cannot re-submit the
URB from ghl_magic_poke() in the window before timer_shutdown_sync() runs.
usb_kill_urb() would not suffice: it only cancels the in-flight URB and
leaves it submittable once it returns, so the pending timer could
re-submit it and put a fresh URB in flight over the freed sc.
timer_shutdown_sync() then drains any last callback and blocks re-arming.
The probe error path is unaffected: it is only reached before the timer
is armed.
Reproduced under KASAN on next-20260710 via dummy_hcd + raw-gadget
emulation of the GHL PS4 dongle (VID 0x1430 / PID 0x07bb): hid-sony binds
and arms the poke timer, the poke URB is held in flight, the driver is
unbound (freeing sc), then the URB is released. The completion re-arms the
timer on the freed sc, and the re-armed timer fires ~8 s later:
BUG: KASAN: slab-use-after-free in ghl_magic_poke+0x98/0xb0
Read of size 8 at addr ffff88810b02fd50 by task swapper/0/0
ghl_magic_poke+0x98/0xb0
call_timer_fn+0x35/0x2b0
__run_timers+0x69c/0x9a0
run_timer_softirq+0x173/0x2a0
Allocated by task 169: sony_probe
Freed by task 338: devres_release_group <- hid_device_remove (sony_remove)
Found by 0sec (https://0sec.ai) using automated source analysis. |
| In the Linux kernel, the following vulnerability has been resolved:
accel/rocket: fix NULL dereference and integer overflow in rocket_job_push()
rocket_job_push() allocates a temporary array to hold all input and
output GEM object pointers:
bos = kvmalloc_array(job->in_bo_count + job->out_bo_count,
sizeof(void *), GFP_KERNEL);
memcpy(bos, job->in_bos, job->in_bo_count * sizeof(void *));
memcpy(&bos[job->in_bo_count], job->out_bos, ...);
Two bugs exist:
1. Missing NULL check: if kvmalloc_array() fails, bos is NULL and
the subsequent memcpy() dereferences it, causing a kernel NULL
pointer dereference.
2. Integer overflow: in_bo_count and out_bo_count are both u32, set
directly from userspace-supplied in_bo_handle_count and
out_bo_handle_count with no prior validation. Their sum is computed
in u32 arithmetic and can wrap to a smaller value, causing the
allocation count passed to kvmalloc_array() to be smaller than
intended. Subsequent uses still operate on the original counts when
copying and locking objects, which may lead to out-of-bounds accesses
on the temporary array.
Fix by using check_add_overflow() to detect count overflow before the
allocation, and adding a NULL check on the allocation result. |
| In the Linux kernel, the following vulnerability has been resolved:
accel/rocket: initialize job domain before cleanup paths
rocket_ioctl_submit_job() releases rjob through rocket_job_put() on
allocation error paths. rocket_job_cleanup() unconditionally calls
rocket_iommu_domain_put(job->domain), but job->domain is assigned only
after task copying and BO lookups. A failure before that assignment can
therefore clean up a job with a NULL domain pointer.
Take the per-file domain reference before the first error path can release
rjob. Also clear rjob->tasks after freeing it in rocket_copy_tasks(), so
the common cleanup path cannot free the task array again after a task-copy
error. |
