| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: fix e4b bitmap inconsistency reports
A bitmap inconsistency issue was observed during stress tests under
mixed huge-page workloads. Ext4 reported multiple e4b bitmap check
failures like:
ext4_mb_complex_scan_group:2508: group 350, 8179 free clusters as
per group info. But got 8192 blocks
Analysis and experimentation confirmed that the issue is caused by a
race condition between page migration and bitmap modification. Although
this timing window is extremely narrow, it is still hit in practice:
folio_lock ext4_mb_load_buddy
__migrate_folio
check ref count
folio_mc_copy __filemap_get_folio
folio_try_get(folio)
......
mb_mark_used
ext4_mb_unload_buddy
__folio_migrate_mapping
folio_ref_freeze
folio_unlock
The root cause of this issue is that the fast path of load_buddy only
increments the folio's reference count, which is insufficient to prevent
concurrent folio migration. We observed that the folio migration process
acquires the folio lock. Therefore, we can determine whether to take the
fast path in load_buddy by checking the lock status. If the folio is
locked, we opt for the slow path (which acquires the lock) to close this
concurrency window.
Additionally, this change addresses the following issues:
When the DOUBLE_CHECK macro is enabled to inspect bitmap-related
issues, the following error may be triggered:
corruption in group 324 at byte 784(6272): f in copy != ff on
disk/prealloc
Analysis reveals that this is a false positive. There is a specific race
window where the bitmap and the group descriptor become momentarily
inconsistent, leading to this error report:
ext4_mb_load_buddy ext4_mb_load_buddy
__filemap_get_folio(create|lock)
folio_lock
ext4_mb_init_cache
folio_mark_uptodate
__filemap_get_folio(no lock)
......
mb_mark_used
mb_mark_used_double
mb_cmp_bitmaps
mb_set_bits(e4b->bd_bitmap)
folio_unlock
The original logic assumed that since mb_cmp_bitmaps is called when the
bitmap is newly loaded from disk, the folio lock would be sufficient to
prevent concurrent access. However, this overlooks a specific race
condition: if another process attempts to load buddy and finds the folio
is already in an uptodate state, it will immediately begin using it without
holding folio lock. |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Clear Present bit before tearing down PASID entry
The Intel VT-d Scalable Mode PASID table entry consists of 512 bits (64
bytes). When tearing down an entry, the current implementation zeros the
entire 64-byte structure immediately using multiple 64-bit writes.
Since the IOMMU hardware may fetch these 64 bytes using multiple
internal transactions (e.g., four 128-bit bursts), updating or zeroing
the entire entry while it is active (P=1) risks a "torn" read. If a
hardware fetch occurs simultaneously with the CPU zeroing the entry, the
hardware could observe an inconsistent state, leading to unpredictable
behavior or spurious faults.
Follow the "Guidance to Software for Invalidations" in the VT-d spec
(Section 6.5.3.3) by implementing the recommended ownership handshake:
1. Clear only the 'Present' (P) bit of the PASID entry.
2. Use a dma_wmb() to ensure the cleared bit is visible to hardware
before proceeding.
3. Execute the required invalidation sequence (PASID cache, IOTLB, and
Device-TLB flush) to ensure the hardware has released all cached
references.
4. Only after the flushes are complete, zero out the remaining fields
of the PASID entry.
Also, add a dma_wmb() in pasid_set_present() to ensure that all other
fields of the PASID entry are visible to the hardware before the Present
bit is set. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nfnetlink_queue: do shared-unconfirmed check before segmentation
Ulrich reports a regression with nfqueue:
If an application did not set the 'F_GSO' capability flag and a gso
packet with an unconfirmed nf_conn entry is received all packets are
now dropped instead of queued, because the check happens after
skb_gso_segment(). In that case, we did have exclusive ownership
of the skb and its associated conntrack entry. The elevated use
count is due to skb_clone happening via skb_gso_segment().
Move the check so that its peformed vs. the aggregated packet.
Then, annotate the individual segments except the first one so we
can do a 2nd check at reinject time.
For the normal case, where userspace does in-order reinjects, this avoids
packet drops: first reinjected segment continues traversal and confirms
entry, remaining segments observe the confirmed entry.
While at it, simplify nf_ct_drop_unconfirmed(): We only care about
unconfirmed entries with a refcnt > 1, there is no need to special-case
dying entries.
This only happens with UDP. With TCP, the only unconfirmed packet will
be the TCP SYN, those aren't aggregated by GRO.
Next patch adds a udpgro test case to cover this scenario. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: drop extent cache after doing PARTIAL_VALID1 zeroout
When splitting an unwritten extent in the middle and converting it to
initialized in ext4_split_extent() with the EXT4_EXT_MAY_ZEROOUT and
EXT4_EXT_DATA_VALID2 flags set, it could leave a stale unwritten extent.
Assume we have an unwritten file and buffered write in the middle of it
without dioread_nolock enabled, it will allocate blocks as written
extent.
0 A B N
[UUUUUUUUUUUU] on-disk extent U: unwritten extent
[UUUUUUUUUUUU] extent status tree
[--DDDDDDDD--] D: valid data
|<- ->| ----> this range needs to be initialized
ext4_split_extent() first try to split this extent at B with
EXT4_EXT_DATA_PARTIAL_VALID1 and EXT4_EXT_MAY_ZEROOUT flag set, but
ext4_split_extent_at() failed to split this extent due to temporary lack
of space. It zeroout B to N and leave the entire extent as unwritten.
0 A B N
[UUUUUUUUUUUU] on-disk extent
[UUUUUUUUUUUU] extent status tree
[--DDDDDDDDZZ] Z: zeroed data
ext4_split_extent() then try to split this extent at A with
EXT4_EXT_DATA_VALID2 flag set. This time, it split successfully and
leave an written extent from A to N.
0 A B N
[UUWWWWWWWWWW] on-disk extent W: written extent
[UUUUUUUUUUUU] extent status tree
[--DDDDDDDDZZ]
Finally ext4_map_create_blocks() only insert extent A to B to the extent
status tree, and leave an stale unwritten extent in the status tree.
0 A B N
[UUWWWWWWWWWW] on-disk extent W: written extent
[UUWWWWWWWWUU] extent status tree
[--DDDDDDDDZZ]
Fix this issue by always cached extent status entry after zeroing out
the second part. |
| In the Linux kernel, the following vulnerability has been resolved:
irqchip/sifive-plic: Fix frozen interrupt due to affinity setting
PLIC ignores interrupt completion message for disabled interrupt, explained
by the specification:
The PLIC signals it has completed executing an interrupt handler by
writing the interrupt ID it received from the claim to the
claim/complete register. The PLIC does not check whether the completion
ID is the same as the last claim ID for that target. If the completion
ID does not match an interrupt source that is currently enabled for
the target, the completion is silently ignored.
This caused problems in the past, because an interrupt can be disabled
while still being handled and plic_irq_eoi() had no effect. That was fixed
by checking if the interrupt is disabled, and if so enable it, before
sending the completion message. That check is done with irqd_irq_disabled().
However, that is not sufficient because the enable bit for the handling
hart can be zero despite irqd_irq_disabled(d) being false. This can happen
when affinity setting is changed while a hart is still handling the
interrupt.
This problem is easily reproducible by dumping a large file to uart (which
generates lots of interrupts) and at the same time keep changing the uart
interrupt's affinity setting. The uart port becomes frozen almost
instantaneously.
Fix this by checking PLIC's enable bit instead of irqd_irq_disabled(). |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix node_cnt race between extent node destroy and writeback
f2fs_destroy_extent_node() does not set FI_NO_EXTENT before clearing
extent nodes. When called from f2fs_drop_inode() with I_SYNC set,
concurrent kworker writeback can insert new extent nodes into the same
extent tree, racing with the destroy and triggering f2fs_bug_on() in
__destroy_extent_node(). The scenario is as follows:
drop inode writeback
- iput
- f2fs_drop_inode // I_SYNC set
- f2fs_destroy_extent_node
- __destroy_extent_node
- while (node_cnt) {
write_lock(&et->lock)
__free_extent_tree
write_unlock(&et->lock)
- __writeback_single_inode
- f2fs_outplace_write_data
- f2fs_update_read_extent_cache
- __update_extent_tree_range
// FI_NO_EXTENT not set,
// insert new extent node
} // node_cnt == 0, exit while
- f2fs_bug_on(node_cnt) // node_cnt > 0
Additionally, __update_extent_tree_range() only checks FI_NO_EXTENT for
EX_READ type, leaving EX_BLOCK_AGE updates completely unprotected.
This patch set FI_NO_EXTENT under et->lock in __destroy_extent_node(),
consistent with other callers (__update_extent_tree_range and
__drop_extent_tree) and check FI_NO_EXTENT for both EX_READ and
EX_BLOCK_AGE tree. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix btrfs_ioctl_space_info() slot_count TOCTOU which can lead to info-leak
btrfs_ioctl_space_info() has a TOCTOU race between two passes over the
block group RAID type lists. The first pass counts entries to determine
the allocation size, then the second pass fills the buffer. The
groups_sem rwlock is released between passes, allowing concurrent block
group removal to reduce the entry count.
When the second pass fills fewer entries than the first pass counted,
copy_to_user() copies the full alloc_size bytes including trailing
uninitialized kmalloc bytes to userspace.
Fix by copying only total_spaces entries (the actually-filled count from
the second pass) instead of alloc_size bytes, and switch to kzalloc so
any future copy size mismatch cannot leak heap data. |
| In the Linux kernel, the following vulnerability has been resolved:
eventfs: Hold eventfs_mutex and SRCU when remount walks events
Commit 340f0c7067a9 ("eventfs: Update all the eventfs_inodes from the
events descriptor") had eventfs_set_attrs() recurse through ei->children
on remount. The walk only holds the rcu_read_lock() taken by
tracefs_apply_options() over tracefs_inodes, which is wrong:
- list_for_each_entry over ei->children races with the list_del_rcu()
in eventfs_remove_rec() -- LIST_POISON1 deref, same shape as
d2603279c7d6.
- eventfs_inodes are freed via call_srcu(&eventfs_srcu, ...).
rcu_read_lock() does not extend an SRCU grace period, so ti->private
can be reclaimed under the walk.
- The writes to ei->attr race with eventfs_set_attr(), which holds
eventfs_mutex.
Reproducer:
while :; do mount -o remount,uid=$((RANDOM%1000)) /sys/kernel/tracing; done &
while :; do
echo "p:kp submit_bio" > /sys/kernel/tracing/kprobe_events
echo > /sys/kernel/tracing/kprobe_events
done
Wrap the events portion of tracefs_apply_options() in
eventfs_remount_lock()/_unlock() that take eventfs_mutex and
srcu_read_lock(&eventfs_srcu). eventfs_set_attrs() doesn't sleep so the
nested rcu_read_lock() is fine; lockdep_assert_held() pins the contract.
Comment in tracefs_drop_inode() said "RCU cycle" -- it is SRCU. |
| In the Linux kernel, the following vulnerability has been resolved:
ipvs: do not keep dest_dst if dev is going down
There is race between the netdev notifier ip_vs_dst_event()
and the code that caches dst with dev that is going down.
As the FIB can be notified for the closed device after our
handler finishes, it is possible valid route to be returned
and cached resuling in a leaked dev reference until the dest
is not removed.
To prevent new dest_dst to be attached to dest just after the
handler dropped the old one, add a netif_running() check
to make sure the notifier handler is not currently running
for device that is closing. |
| In the Linux kernel, the following vulnerability has been resolved:
xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path
icmp_route_lookup() performs multiple route lookups to find a suitable
route for sending ICMP error messages, with special handling for XFRM
(IPsec) policies.
The lookup sequence is:
1. First, lookup output route for ICMP reply (dst = original src)
2. Pass through xfrm_lookup() for policy check
3. If blocked (-EPERM) or dst is not local, enter "reverse path"
4. In reverse path, call xfrm_decode_session_reverse() to get fl4_dec
which reverses the original packet's flow (saddr<->daddr swapped)
5. If fl4_dec.saddr is local (we are the original destination), use
__ip_route_output_key() for output route lookup
6. If fl4_dec.saddr is NOT local (we are a forwarding node), use
ip_route_input() to simulate the reverse packet's input path
7. Finally, pass rt2 through xfrm_lookup() with XFRM_LOOKUP_ICMP flag
The bug occurs in step 6: ip_route_input() is called with fl4_dec.daddr
(original packet's source) as destination. If this address becomes local
between the initial check and ip_route_input() call (e.g., due to
concurrent "ip addr add"), ip_route_input() returns a LOCAL route with
dst.output set to ip_rt_bug.
This route is then used for ICMP output, causing dst_output() to call
ip_rt_bug(), triggering a WARN_ON:
------------[ cut here ]------------
WARNING: net/ipv4/route.c:1275 at ip_rt_bug+0x21/0x30, CPU#1
Call Trace:
<TASK>
ip_push_pending_frames+0x202/0x240
icmp_push_reply+0x30d/0x430
__icmp_send+0x1149/0x24f0
ip_options_compile+0xa2/0xd0
ip_rcv_finish_core+0x829/0x1950
ip_rcv+0x2d7/0x420
__netif_receive_skb_one_core+0x185/0x1f0
netif_receive_skb+0x90/0x450
tun_get_user+0x3413/0x3fb0
tun_chr_write_iter+0xe4/0x220
...
Fix this by checking rt2->rt_type after ip_route_input(). If it's
RTN_LOCAL, the route cannot be used for output, so treat it as an error.
The reproducer requires kernel modification to widen the race window,
making it unsuitable as a selftest. It is available at:
https://gist.github.com/mrpre/eae853b72ac6a750f5d45d64ddac1e81 |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Require frozen map for calculating map hash
Currently, bpf_map_get_info_by_fd calculates and caches the hash of the
map regardless of the map's frozen state.
This leads to a TOCTOU bug where userspace can call
BPF_OBJ_GET_INFO_BY_FD to cache the hash and then modify the map
contents before freezing.
Therefore, a trusted loader can be tricked into verifying the stale hash
while loading the modified contents.
Fix this by returning -EPERM if the map is not frozen when the hash is
requested. This ensures the hash is only generated for the final,
immutable state of the map. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/damon/sysfs-schemes: protect memcg_path kfree() with damon_sysfs_lock
Patch series "mm/damon/sysfs-schemes: fix use-after-free for [memcg_]path".
Reads of 'memcg_path' and 'path' files in DAMON sysfs interface could race
with their writes, results in use-after-free. Fix those.
This patch (of 2):
damon_sysfs_scheme_filter->mmecg_path can be read and written by users,
via DAMON sysfs memcg_path file. It can also be indirectly read, for the
parameters {on,off}line committing to DAMON. The reads for parameters
committing are protected by damon_sysfs_lock to avoid the sysfs files
being destroyed while any of the parameters are being read. But the
user-driven direct reads and writes are not protected by any lock, while
the write is deallocating the memcg_path-pointing buffer. As a result,
the readers could read the already freed buffer (user-after-free). Note
that the user-reads don't race when the same open file is used by the
writer, due to kernfs's open file locking. Nonetheless, doing the reads
and writes with separate open files would be common. Fix it by protecting
both the user-direct reads and writes with damon_sysfs_lock. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before submitting I/O
When allocating blocks during within-EOF DIO and writeback with
dioread_nolock enabled, EXT4_GET_BLOCKS_PRE_IO was set to split an
existing large unwritten extent. However, EXT4_GET_BLOCKS_CONVERT was
set when calling ext4_split_convert_extents(), which may potentially
result in stale data issues.
Assume we have an unwritten extent, and then DIO writes the second half.
[UUUUUUUUUUUUUUUU] on-disk extent U: unwritten extent
[UUUUUUUUUUUUUUUU] extent status tree
|<- ->| ----> dio write this range
First, ext4_iomap_alloc() call ext4_map_blocks() with
EXT4_GET_BLOCKS_PRE_IO, EXT4_GET_BLOCKS_UNWRIT_EXT and
EXT4_GET_BLOCKS_CREATE flags set. ext4_map_blocks() find this extent and
call ext4_split_convert_extents() with EXT4_GET_BLOCKS_CONVERT and the
above flags set.
Then, ext4_split_convert_extents() calls ext4_split_extent() with
EXT4_EXT_MAY_ZEROOUT, EXT4_EXT_MARK_UNWRIT2 and EXT4_EXT_DATA_VALID2
flags set, and it calls ext4_split_extent_at() to split the second half
with EXT4_EXT_DATA_VALID2, EXT4_EXT_MARK_UNWRIT1, EXT4_EXT_MAY_ZEROOUT
and EXT4_EXT_MARK_UNWRIT2 flags set. However, ext4_split_extent_at()
failed to insert extent since a temporary lack -ENOSPC. It zeroes out
the first half but convert the entire on-disk extent to written since
the EXT4_EXT_DATA_VALID2 flag set, but left the second half as unwritten
in the extent status tree.
[0000000000SSSSSS] data S: stale data, 0: zeroed
[WWWWWWWWWWWWWWWW] on-disk extent W: written extent
[WWWWWWWWWWUUUUUU] extent status tree
Finally, if the DIO failed to write data to the disk, the stale data in
the second half will be exposed once the cached extent entry is gone.
Fix this issue by not passing EXT4_GET_BLOCKS_CONVERT when splitting
an unwritten extent before submitting I/O, and make
ext4_split_convert_extents() to zero out the entire extent range
to zero for this case, and also mark the extent in the extent status
tree for consistency. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: algif_aead - snapshot IV for async AEAD requests
AF_ALG AEAD AIO requests currently use the socket-wide IV buffer during
request processing. For async requests, later socket activity can
update that shared state before the original request has fully
completed, which can lead to inconsistent IV handling.
Snapshot the IV into per-request storage when preparing the AEAD
request, so in-flight operations no longer depend on mutable socket
state. |
| In the Linux kernel, the following vulnerability has been resolved:
mm: fix deferred split queue races during migration
migrate_folio_move() records the deferred split queue state from src and
replays it on dst. Replaying it after remove_migration_ptes(src, dst, 0)
makes dst visible before it is requeued, so a concurrent rmap-removal path
can mark dst partially mapped and trip the WARN in deferred_split_folio().
Move the requeue before remove_migration_ptes() so dst is back on the
deferred split queue before it becomes visible again.
Because migration still holds dst locked at that point, teach
deferred_split_scan() to requeue a folio when folio_trylock() fails.
Otherwise a fully mapped underused folio can be dequeued by the shrinker
and silently lost from split_queue.
[[email protected]: move the comment] |
| In the Linux kernel, the following vulnerability has been resolved:
net: bridge: use a stable FDB dst snapshot in RCU readers
Local FDB entries can be rewritten in place by `fdb_delete_local()`, which
updates `f->dst` to another port or to `NULL` while keeping the entry
alive. Several bridge RCU readers inspect `f->dst`, including
`br_fdb_fillbuf()` through the `brforward_read()` sysfs path.
These readers currently load `f->dst` multiple times and can therefore
observe inconsistent values across the check and later dereference.
In `br_fdb_fillbuf()`, this means a concurrent local-FDB update can change
`f->dst` after the NULL check and before the `port_no` dereference,
leading to a NULL-ptr-deref.
Fix this by taking a single `READ_ONCE()` snapshot of `f->dst` in each
affected RCU reader and using that snapshot for the rest of the access
sequence. Also publish the in-place `f->dst` updates in `fdb_delete_local()`
with `WRITE_ONCE()` so the readers and writer use matching access patterns. |
| MaxKB is an open-source AI assistant for enterprise. MaxKB 2.8.0 and prior are vulnerable to a server-side request forgery (SSRF) bypass in the OSS file service URL fetch functionality due to inconsistent DNS resolution between validation and actual request execution, allowing attackers to access internal network services. This vulnerability is fixed in 2.8.1. |
| In the Linux kernel, the following vulnerability has been resolved:
accel/amdxdna: Fix race condition when checking rpm_on
When autosuspend is triggered, driver rpm_on flag is set to indicate that
a suspend/resume is already in progress. However, when a userspace
application submits a command during this narrow window,
amdxdna_pm_resume_get() may incorrectly skip the resume operation because
the rpm_on flag is still set. This results in commands being submitted
while the device has not actually resumed, causing unexpected behavior.
The set_dpm() is called by suspend/resume, it relied on rpm_on flag to
avoid calling into rpm suspend/resume recursivly. So to fix this, remove
the use of the rpm_on flag entirely. Instead, introduce aie2_pm_set_dpm()
which explicitly resumes the device before invoking set_dpm(). With this
change, set_dpm() is called directly inside the suspend or resume execution
path. Otherwise, aie2_pm_set_dpm() is called. |
| NVIDIA Display Driver for Windows contains a vulnerability where an attacker could cause a time-of-check time-of-use issue. A successful exploit of this vulnerability might lead to denial of service, escalation of privileges, information disclosure, data tampering, and code execution. |
| In the Linux kernel, the following vulnerability has been resolved:
nouveau/dpcd: return EBUSY for aux xfer if the device is asleep
If we have runtime suspended, and userspace wants to use /dev/drm_dp_*
then just tell it the device is busy instead of crashing in the GSP
code.
WARNING: CPU: 2 PID: 565741 at drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/rpc.c:164 r535_gsp_msgq_wait+0x9a/0xb0 [nouveau]
CPU: 2 UID: 0 PID: 565741 Comm: fwupd Not tainted 6.18.10-200.fc43.x86_64 #1 PREEMPT(lazy)
Hardware name: LENOVO 20QTS0PQ00/20QTS0PQ00, BIOS N2OET65W (1.52 ) 08/05/2024
RIP: 0010:r535_gsp_msgq_wait+0x9a/0xb0 [nouveau]
This is a simple fix to get backported. We should probably engineer a
proper power domain solution to wake up devices and keep them awake
while fw updates are happening. |
