Linux: >> Linux Kernel >> 2.6.39.4 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
net: phonet: free phonet_device after RCU grace period
phonet_device_destroy() removes a phonet_device from the per-net device
list with list_del_rcu(), but frees it immediately. RCU readers walking
the same list can still hold a pointer to the object after it has been
removed, leading to a slab-use-after-free.
Use kfree_rcu(), matching the lifetime rule already used by
phonet_address_del() for the same object type.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
netfilter: require Ethernet MAC header before using eth_hdr()
`ip6t_eui64`, `xt_mac`, the `bitmap:ip,mac`, `hash:ip,mac`, and
`hash:mac` ipset types, and `nf_log_syslog` access `eth_hdr(skb)`
after either assuming that the skb is associated with an Ethernet
device or checking only that the `ETH_HLEN` bytes at
`skb_mac_header(skb)` lie between `skb->head` and `skb->data`.
Make these paths first verify that the skb is associated with an
Ethernet device, that the MAC header was set, and that it spans at
least a full Ethernet header before accessing `eth_hdr(skb)`.
CVSS Score
9.4
EPSS Score
0.004
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START
omfs_fill_super() rejects oversized s_sys_blocksize values (> PAGE_SIZE),
but it does not reject values smaller than OMFS_DIR_START (0x1b8 = 440).
Later, omfs_make_empty() uses
sbi->s_sys_blocksize - OMFS_DIR_START
as the length argument to memset(). Since s_sys_blocksize is u32,
a crafted filesystem image with s_sys_blocksize < OMFS_DIR_START causes
an unsigned underflow there, wrapping to a value near 2^32. That drives
a ~4 GiB memset() from bh->b_data + OMFS_DIR_START and overwrites kernel
memory far beyond the backing block buffer.
Add the corresponding lower-bound check alongside the existing upper-bound
check in omfs_fill_super(), so that malformed images are rejected during
superblock validation before any filesystem data is processed.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
wifi: rtlwifi: pci: fix possible use-after-free caused by unfinished irq_prepare_bcn_tasklet
The irq_prepare_bcn_tasklet is initialized in rtl_pci_init() and
scheduled when RTL_IMR_BCNINT interrupt is triggered by hardware.
But it is never killed in rtl_pci_deinit(). When the rtlwifi card
probe fails or is being detached, the ieee80211_hw is deallocated.
However, irq_prepare_bcn_tasklet may still be running or pending,
leading to use-after-free when the freed ieee80211_hw is accessed
in _rtl_pci_prepare_bcn_tasklet().
Similar to irq_tasklet, add tasklet_kill() in rtl_pci_deinit() to
ensure that irq_prepare_bcn_tasklet is properly terminated before
the ieee80211_hw is released.
The issue was identified through static analysis.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
net: hamradio: 6pack: fix uninit-value in sixpack_receive_buf
sixpack_receive_buf() does not properly skip bytes with TTY error flags.
The while loop iterates through the flags buffer but never advances the
data pointer (cp), and passes the original count (including error bytes)
to sixpack_decode(). This causes sixpack_decode() to process bytes that
should have been skipped due to TTY errors. The TTY layer does not
guarantee that cp[i] holds a meaningful value when fp[i] is set, so
passing those positions to sixpack_decode() results in KMSAN reporting
an uninit-value read.
Fix this by processing bytes one at a time, advancing cp on each
iteration, and only passing valid (non-error) bytes to sixpack_decode().
This matches the pattern used by slip_receive_buf() and
mkiss_receive_buf() for the same purpose.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
ppp: require CAP_NET_ADMIN in target netns for unattached ioctls
/dev/ppp open is currently authorized against file->f_cred->user_ns,
while unattached administrative ioctls operate on current->nsproxy->net_ns.
As a result, a local unprivileged user can create a new user namespace
with CLONE_NEWUSER, gain CAP_NET_ADMIN only in that new user namespace,
and still issue PPPIOCNEWUNIT, PPPIOCATTACH, or PPPIOCATTCHAN against
an inherited network namespace.
Require CAP_NET_ADMIN in the user namespace that owns the target network
namespace before handling unattached PPP administrative ioctls.
This preserves normal pppd operation in the network namespace it is
actually privileged in, while rejecting the userns-only inherited-netns
case.
CVSS Score
8.8
EPSS Score
0.003
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
dm log: fix out-of-bounds write due to region_count overflow
The local variable region_count in create_log_context() is declared as
unsigned int (32-bit), but dm_sector_div_up() returns sector_t (64-bit).
When a device-mapper target has a sufficiently large ti->len with a small
region_size, the division result can exceed UINT_MAX. The truncated
value is then used to calculate bitset_size, causing clean_bits,
sync_bits, and recovering_bits to be allocated far smaller than needed
for the actual number of regions.
Subsequent log operations (log_set_bit, log_clear_bit, log_test_bit) use
region indices derived from the full untruncated region space, causing
out-of-bounds writes to kernel heap memory allocated by vmalloc.
This can be reproduced by creating a mirror target whose region_count
overflows 32 bits:
dmsetup create bigzero --table '0 8589934594 zero'
dmsetup create mymirror --table '0 8589934594 mirror \
core 2 2 nosync 2 /dev/mapper/bigzero 0 \
/dev/mapper/bigzero 0'
The status output confirms the truncation (sync_count=1 instead of
4294967297, because 0x100000001 was truncated to 1):
$ dmsetup status mymirror
0 8589934594 mirror 2 254:1 254:1 1/4294967297 ...
This leads to a kernel crash in core_in_sync:
BUG: scheduling while atomic: (udev-worker)/9150/0x00000000
RIP: 0010:core_in_sync+0x14/0x30 [dm_log]
CR2: 0000000000000008
Fixing recursive fault but reboot is needed!
Fix by widening the local region_count to sector_t and adding an
explicit overflow check before the value is assigned to lc->region_count.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
ocfs2/dlm: validate qr_numregions in dlm_match_regions()
Patch series "ocfs2/dlm: fix two bugs in dlm_match_regions()".
In dlm_match_regions(), the qr_numregions field from a DLM_QUERY_REGION
network message is used to drive loops over the qr_regions buffer without
sufficient validation. This series fixes two issues:
- Patch 1 adds a bounds check to reject messages where qr_numregions
exceeds O2NM_MAX_REGIONS. The o2net layer only validates message
byte length; it does not constrain field values, so a crafted message
can set qr_numregions up to 255 and trigger out-of-bounds reads past
the 1024-byte qr_regions buffer.
- Patch 2 fixes an off-by-one in the local-vs-remote comparison loop,
which uses '<=' instead of '<', reading one entry past the valid range
even when qr_numregions is within bounds.
This patch (of 2):
The qr_numregions field from a DLM_QUERY_REGION network message is used
directly as loop bounds in dlm_match_regions() without checking against
O2NM_MAX_REGIONS. Since qr_regions is sized for at most O2NM_MAX_REGIONS
(32) entries, a crafted message with qr_numregions > 32 causes
out-of-bounds reads past the qr_regions buffer.
Add a bounds check for qr_numregions before entering the loops.
CVSS Score
9.1
EPSS Score
0.005
Published
2026-06-24
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
0.001
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