Linux: >> Linux Kernel >> 4.9.279 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate group add input before caching
[BUG]
OCFS2_IOC_GROUP_ADD can trigger a BUG_ON in
ocfs2_set_new_buffer_uptodate():
kernel BUG at fs/ocfs2/uptodate.c:509!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:ocfs2_set_new_buffer_uptodate+0x194/0x1e0 fs/ocfs2/uptodate.c:509
Code: ffffe88f 42b9fe4c 89e64889 dfe8b4df
Call Trace:
ocfs2_group_add+0x3f1/0x1510 fs/ocfs2/resize.c:507
ocfs2_ioctl+0x309/0x6e0 fs/ocfs2/ioctl.c:887
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x197/0x1e0 fs/ioctl.c:583
x64_sys_call+0x1144/0x26a0 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x93/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7bbfb55a966d
[CAUSE]
ocfs2_group_add() calls ocfs2_set_new_buffer_uptodate() on a
user-controlled group block before ocfs2_verify_group_and_input()
validates that block number. That helper is only valid for newly
allocated metadata and asserts that the block is not already present in
the chosen metadata cache. The code also uses INODE_CACHE(inode) even
though the group descriptor belongs to main_bm_inode and later journal
accesses use that cache context instead.
[FIX]
Validate the on-disk group descriptor before caching it, then add it to
the metadata cache tracked by INODE_CACHE(main_bm_inode). Keep the
validation failure path separate from the later cleanup path so we only
remove the buffer from that cache after it has actually been inserted.
This keeps the group buffer lifetime consistent across validation,
journaling, and cleanup.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate bg_bits during freefrag scan
[BUG]
A crafted filesystem can trigger an out-of-bounds bitmap walk when
OCFS2_IOC_INFO is issued with OCFS2_INFO_FL_NON_COHERENT.
BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: use-after-free in test_bit_le include/asm-generic/bitops/le.h:21 [inline]
BUG: KASAN: use-after-free in ocfs2_info_freefrag_scan_chain fs/ocfs2/ioctl.c:495 [inline]
BUG: KASAN: use-after-free in ocfs2_info_freefrag_scan_bitmap fs/ocfs2/ioctl.c:588 [inline]
BUG: KASAN: use-after-free in ocfs2_info_handle_freefrag fs/ocfs2/ioctl.c:662 [inline]
BUG: KASAN: use-after-free in ocfs2_info_handle_request+0x1c66/0x3370 fs/ocfs2/ioctl.c:754
Read of size 8 at addr ffff888031bce000 by task syz.0.636/1435
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0xbe/0x130 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xd1/0x650 mm/kasan/report.c:482
kasan_report+0xfb/0x140 mm/kasan/report.c:595
check_region_inline mm/kasan/generic.c:186 [inline]
kasan_check_range+0x11c/0x200 mm/kasan/generic.c:200
__kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31
instrument_atomic_read include/linux/instrumented.h:68 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
test_bit_le include/asm-generic/bitops/le.h:21 [inline]
ocfs2_info_freefrag_scan_chain fs/ocfs2/ioctl.c:495 [inline]
ocfs2_info_freefrag_scan_bitmap fs/ocfs2/ioctl.c:588 [inline]
ocfs2_info_handle_freefrag fs/ocfs2/ioctl.c:662 [inline]
ocfs2_info_handle_request+0x1c66/0x3370 fs/ocfs2/ioctl.c:754
ocfs2_info_handle+0x18d/0x2a0 fs/ocfs2/ioctl.c:828
ocfs2_ioctl+0x632/0x6e0 fs/ocfs2/ioctl.c:913
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x197/0x1e0 fs/ioctl.c:583
...
[CAUSE]
ocfs2_info_freefrag_scan_chain() uses on-disk bg_bits directly as the
bitmap scan limit. The coherent path reads group descriptors through
ocfs2_read_group_descriptor(), which validates the descriptor before
use. The non-coherent path uses ocfs2_read_blocks_sync() instead and
skips that validation, so an impossible bg_bits value can drive the
bitmap walk past the end of the block.
[FIX]
Compute the bitmap capacity from the filesystem format with
ocfs2_group_bitmap_size(), report descriptors whose bg_bits exceeds
that limit, and clamp the scan to the computed capacity. This keeps the
freefrag report going while avoiding reads beyond the buffer.
CVSS Score
7.1
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix listxattr handling when the buffer is full
[BUG]
If an OCFS2 inode has both inline and block-based xattrs, listxattr()
can return a size larger than the caller's buffer when the inline names
consume that buffer exactly.
kernel BUG at mm/usercopy.c:102!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:usercopy_abort+0xb7/0xd0 mm/usercopy.c:102
Call Trace:
__check_heap_object+0xe3/0x120 mm/slub.c:8243
check_heap_object mm/usercopy.c:196 [inline]
__check_object_size mm/usercopy.c:250 [inline]
__check_object_size+0x5c5/0x780 mm/usercopy.c:215
check_object_size include/linux/ucopysize.h:22 [inline]
check_copy_size include/linux/ucopysize.h:59 [inline]
copy_to_user include/linux/uaccess.h:219 [inline]
listxattr+0xb0/0x170 fs/xattr.c:926
filename_listxattr fs/xattr.c:958 [inline]
path_listxattrat+0x137/0x320 fs/xattr.c:988
__do_sys_listxattr fs/xattr.c:1001 [inline]
__se_sys_listxattr fs/xattr.c:998 [inline]
__x64_sys_listxattr+0x7f/0xd0 fs/xattr.c:998
...
[CAUSE]
Commit 936b8834366e ("ocfs2: Refactor xattr list and remove
ocfs2_xattr_handler().") replaced the old per-handler list accounting
with ocfs2_xattr_list_entry(), but it kept using size == 0 to detect
probe mode.
That assumption stops being true once ocfs2_listxattr() finishes the
inline-xattr pass. If the inline names fill the caller buffer exactly,
the block-xattr pass runs with a non-NULL buffer and a remaining size of
zero. ocfs2_xattr_list_entry() then skips the bounds check, keeps
counting block names, and returns a positive size larger than the
supplied buffer.
[FIX]
Detect probe mode by testing whether the destination buffer pointer is
NULL instead of whether the remaining size is zero.
That restores the pre-refactor behavior and matches the OCFS2 getxattr
helpers. Once the remaining buffer reaches zero while more names are
left, the block-xattr pass now returns -ERANGE instead of reporting a
size larger than the allocated list buffer.
CVSS Score
7.1
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix data loss caused by incorrect use of nat_entry flag
Data loss can occur when fsync is performed on a newly created file
(before any checkpoint has been written) concurrently with a checkpoint
operation. The scenario is as follows:
create & write & fsync 'file A' write checkpoint
- f2fs_do_sync_file // inline inode
- f2fs_write_inode // inode folio is dirty
- f2fs_write_checkpoint
- f2fs_flush_merged_writes
- f2fs_sync_node_pages
- f2fs_flush_nat_entries
- f2fs_fsync_node_pages // no dirty node
- f2fs_need_inode_block_update // return false
SPO and lost 'file A'
f2fs_flush_nat_entries() sets the IS_CHECKPOINTED and HAS_LAST_FSYNC
flags for the nat_entry, but this does not mean that the checkpoint has
actually completed successfully. However, f2fs_need_inode_block_update()
checks these flags and incorrectly assumes that the checkpoint has
finished.
The root cause is that the semantics of IS_CHECKPOINTED and
HAS_LAST_FSYNC are only guaranteed after the checkpoint write fully
completes.
This patch modifies f2fs_need_inode_block_update() to acquire the
sbi->node_write lock before reading the nat_entry flags, ensuring that
once IS_CHECKPOINTED and HAS_LAST_FSYNC are observed to be set, the
checkpoint operation has already completed.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
scsi: target: core: Fix integer overflow in UNMAP bounds check
sbc_execute_unmap() checks LBA + range does not exceed the device capacity,
but does not guard against LBA + range wrapping around on 64-bit overflow.
Add an overflow check matching the pattern already used for WRITE_SAME in
the same file.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
greybus: raw: fix use-after-free if write is called after disconnect
If a user writes to the chardev after disconnect has been called, the
kernel panics with the following trace (with
CONFIG_INIT_ON_FREE_DEFAULT_ON=y):
BUG: kernel NULL pointer dereference, address: 0000000000000218
...
Call Trace:
<TASK>
gb_operation_create_common+0x61/0x180
gb_operation_create_flags+0x28/0xa0
gb_operation_sync_timeout+0x6f/0x100
raw_write+0x7b/0xc7 [gb_raw]
vfs_write+0xcf/0x420
? task_mm_cid_work+0x136/0x220
ksys_write+0x63/0xe0
do_syscall_64+0xa4/0x290
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Disconnect calls gb_connection_destroy, which ends up freeing the
connection object. When gb_operation_sync is called in the write file
operations, its gets a freed connection as parameter and the kernel
panics.
The gb_connection_destroy cannot be moved out of the disconnect
function, as the Greybus subsystem expect all connections belonging to a
bundle to be destroyed when disconnect returns.
To prevent this bug, use a rw lock to synchronize access between write
and disconnect. This guarantees that the write function doesn't try
to use a disconnected connection.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
greybus: raw: fix use-after-free on cdev close
This addresses a use-after-free bug when a raw bundle is disconnected
but its chardev is still opened by an application. When the application
releases the cdev, it causes the following panic when init on free is
enabled (CONFIG_INIT_ON_FREE_DEFAULT_ON=y):
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 139 at lib/refcount.c:28 refcount_warn_saturate+0xd0/0x130
...
Call Trace:
<TASK>
cdev_put+0x18/0x30
__fput+0x255/0x2a0
__x64_sys_close+0x3d/0x80
do_syscall_64+0xa4/0x290
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The cdev is contained in the "gb_raw" structure, which is freed in the
disconnect operation. When the cdev is released at a later time,
cdev_put gets an address that points to freed memory.
To fix this use-after-free, convert the struct device from a pointer to
being embedded, that makes the lifetime of the cdev and of this device
the same. Then, use cdev_device_add, which guarantees that the device
won't be released until all references to the cdev have been released.
Finally, delegate the freeing of the structure to the device release
function, instead of freeing immediately in the disconnect callback.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
netfilter: xtables: restrict several matches to inet family
This is a partial revert of:
commit ab4f21e6fb1c ("netfilter: xtables: use NFPROTO_UNSPEC in more extensions")
to allow ipv4 and ipv6 only.
- xt_mac
- xt_owner
- xt_physdev
These extensions are not used by ebtables in userspace.
Moreover, xt_realm is only for ipv4, since dst->tclassid is ipv4
specific.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
sctp: fix OOB write to userspace in sctp_getsockopt_peer_auth_chunks
sctp_getsockopt_peer_auth_chunks() checks that the caller's optval
buffer is large enough for the peer AUTH chunk list with
if (len < num_chunks)
return -EINVAL;
but then writes num_chunks bytes to p->gauth_chunks, which lives
at offset offsetof(struct sctp_authchunks, gauth_chunks) == 8
inside optval. The check is missing the sizeof(struct
sctp_authchunks) = 8-byte header. When the caller supplies
len == num_chunks (for any num_chunks > 0) the test passes but
copy_to_user() writes sizeof(struct sctp_authchunks) = 8 bytes
past the declared buffer.
The sibling function sctp_getsockopt_local_auth_chunks() at the
next line already has the correct check:
if (len < sizeof(struct sctp_authchunks) + num_chunks)
return -EINVAL;
Align the peer variant with its sibling.
Reproducer confirms on v7.0-13-generic: an unprivileged userspace
caller that opens a loopback SCTP association with AUTH enabled,
queries num_chunks with a short optval, then issues the real
getsockopt with len == num_chunks and sentinel bytes painted past
the buffer observes those sentinel bytes overwritten with the
peer's AUTH chunk type. The bytes written are under the peer's
control but land in the caller's own userspace; this is not a
kernel memory corruption, but it is a kernel-side contract
violation that can silently corrupt adjacent userspace data.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
netfilter: conntrack: remove sprintf usage
Replace it with scnprintf, the buffer sizes are expected to be large enough
to hold the result, no need for snprintf+overflow check.
Increase buffer size in mangle_content_len() while at it.
BUG: KASAN: stack-out-of-bounds in vsnprintf+0xea5/0x1270
Write of size 1 at addr [..]
vsnprintf+0xea5/0x1270
sprintf+0xb1/0xe0
mangle_content_len+0x1ac/0x280
nf_nat_sdp_session+0x1cc/0x240
process_sdp+0x8f8/0xb80
process_invite_request+0x108/0x2b0
process_sip_msg+0x5da/0xf50
sip_help_tcp+0x45e/0x780
nf_confirm+0x34d/0x990
[..]
CVSS Score
9.8
EPSS Score
0.004
Published
2026-06-24