Linux: >> Linux Kernel >> 4.14.318 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
hfsplus: fix held lock freed on hfsplus_fill_super()
hfsplus_fill_super() calls hfs_find_init() to initialize a search
structure, which acquires tree->tree_lock. If the subsequent call to
hfsplus_cat_build_key() fails, the function jumps to the out_put_root
error label without releasing the lock. The later cleanup path then
frees the tree data structure with the lock still held, triggering a
held lock freed warning.
Fix this by adding the missing hfs_find_exit(&fd) call before jumping
to the out_put_root error label. This ensures that tree->tree_lock is
properly released on the error path.
The bug was originally detected on v6.13-rc1 using an experimental
static analysis tool we are developing, and we have verified that the
issue persists in the latest mainline kernel. The tool is specifically
designed to detect memory management issues. It is currently under active
development and not yet publicly available.
We confirmed the bug by runtime testing under QEMU with x86_64 defconfig,
lockdep enabled, and CONFIG_HFSPLUS_FS=y. To trigger the error path, we
used GDB to dynamically shrink the max_unistr_len parameter to 1 before
hfsplus_asc2uni() is called. This forces hfsplus_asc2uni() to naturally
return -ENAMETOOLONG, which propagates to hfsplus_cat_build_key() and
exercises the faulty error path. The following warning was observed
during mount:
=========================
WARNING: held lock freed!
7.0.0-rc3-00016-gb4f0dd314b39 #4 Not tainted
-------------------------
mount/174 is freeing memory ffff888103f92000-ffff888103f92fff, with a lock still held there!
ffff888103f920b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x154/0x1e0
2 locks held by mount/174:
#0: ffff888103f960e0 (&type->s_umount_key#42/1){+.+.}-{4:4}, at: alloc_super.constprop.0+0x167/0xa40
#1: ffff888103f920b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x154/0x1e0
stack backtrace:
CPU: 2 UID: 0 PID: 174 Comm: mount Not tainted 7.0.0-rc3-00016-gb4f0dd314b39 #4 PREEMPT(lazy)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x82/0xd0
debug_check_no_locks_freed+0x13a/0x180
kfree+0x16b/0x510
? hfsplus_fill_super+0xcb4/0x18a0
hfsplus_fill_super+0xcb4/0x18a0
? __pfx_hfsplus_fill_super+0x10/0x10
? srso_return_thunk+0x5/0x5f
? bdev_open+0x65f/0xc30
? srso_return_thunk+0x5/0x5f
? pointer+0x4ce/0xbf0
? trace_contention_end+0x11c/0x150
? __pfx_pointer+0x10/0x10
? srso_return_thunk+0x5/0x5f
? bdev_open+0x79b/0xc30
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? vsnprintf+0x6da/0x1270
? srso_return_thunk+0x5/0x5f
? __mutex_unlock_slowpath+0x157/0x740
? __pfx_vsnprintf+0x10/0x10
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? mark_held_locks+0x49/0x80
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? irqentry_exit+0x17b/0x5e0
? trace_irq_disable.constprop.0+0x116/0x150
? __pfx_hfsplus_fill_super+0x10/0x10
? __pfx_hfsplus_fill_super+0x10/0x10
get_tree_bdev_flags+0x302/0x580
? __pfx_get_tree_bdev_flags+0x10/0x10
? vfs_parse_fs_qstr+0x129/0x1a0
? __pfx_vfs_parse_fs_qstr+0x3/0x10
vfs_get_tree+0x89/0x320
fc_mount+0x10/0x1d0
path_mount+0x5c5/0x21c0
? __pfx_path_mount+0x10/0x10
? trace_irq_enable.constprop.0+0x116/0x150
? trace_irq_enable.constprop.0+0x116/0x150
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? kmem_cache_free+0x307/0x540
? user_path_at+0x51/0x60
? __x64_sys_mount+0x212/0x280
? srso_return_thunk+0x5/0x5f
__x64_sys_mount+0x212/0x280
? __pfx___x64_sys_mount+0x10/0x10
? srso_return_thunk+0x5/0x5f
? trace_irq_enable.constprop.0+0x116/0x150
? srso_return_thunk+0x5/0x5f
do_syscall_64+0x111/0x680
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffacad55eae
Code: 48 8b 0d 85 1f 0f 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 8
RSP: 002b
---truncated---
CVSS Score
7.0
EPSS Score
0.001
Published
2026-06-08
In the Linux kernel, the following vulnerability has been resolved:
spi: topcliff-pch: fix use-after-free on unbind
Give the driver a chance to flush its queue before releasing the DMA
buffers on driver unbind
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-08
In the Linux kernel, the following vulnerability has been resolved:
selinux: allow multiple opens of /sys/fs/selinux/policy
Currently there can only be a single open of /sys/fs/selinux/policy at
any time. This allows any process to block any other process from
reading the kernel policy. The original motivation seems to have been
a mix of preventing an inconsistent view of the policy size and
preventing userspace from allocating kernel memory without bound, but
this is arguably equally bad. Eliminate the policy_opened flag and
shrink the critical section that the policy mutex is held. While we
are making changes here, drop a couple of extraneous BUG_ONs.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-08
In the Linux kernel, the following vulnerability has been resolved:
isofs: validate Rock Ridge CE continuation extent against volume size
rock_continue() reads rs->cont_extent verbatim from the Rock Ridge CE
record and passes it to sb_bread() without checking that the block
number is within the mounted ISO 9660 volume. commit e595447e177b
("[PATCH] rock.c: handle corrupted directories") added cont_offset
and cont_size rejection for the CE continuation but did not validate
the extent block number itself. commit f54e18f1b831 ("isofs: Fix
infinite looping over CE entries") later capped the CE chain length
at RR_MAX_CE_ENTRIES = 32 but again left the block number unchecked.
With a crafted ISO mounted via udisks2 (desktop optical auto-mount)
or via CAP_SYS_ADMIN mount, rs->cont_extent can therefore point at
an out-of-range block or at blocks belonging to an adjacent
filesystem on the same block device. sb_bread() on an out-of-range
block returns NULL cleanly via the block layer EIO path, so there
is no memory-safety violation. For in-range reads of adjacent-
filesystem data, the CE buffer is parsed as Rock Ridge records and
only the text of SL sub-records reaches userspace through
readlink(), which makes the info-leak channel narrow and difficult
to exploit; still, rejecting the malformed CE outright matches the
rejection shape already present in the same function for
cont_offset and cont_size.
Add an ISOFS_SB(sb)->s_nzones bounds check to rock_continue() next
to the existing offset/size rejection, printing the same
corrupted-directory-entry notice.
CVSS Score
8.2
EPSS Score
0.003
Published
2026-06-08
In the Linux kernel, the following vulnerability has been resolved:
crypto: caam - guard HMAC key hex dumps in hash_digest_key
Use print_hex_dump_devel() for dumping sensitive HMAC key bytes in
hash_digest_key() to avoid leaking secrets at runtime when
CONFIG_DYNAMIC_DEBUG is enabled.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-08
In the Linux kernel, the following vulnerability has been resolved:
dm: fix a buffer overflow in ioctl processing
Tony Asleson (using Claude) found a buffer overflow in dm-ioctl in the
function retrieve_status:
1. The code in retrieve_status checks that the output string fits into
the output buffer and writes the output string there
2. Then, the code aligns the "outptr" variable to the next 8-byte
boundary:
outptr = align_ptr(outptr);
3. The alignment doesn't check overflow, so outptr could point past the
buffer end
4. The "for" loop is iterated again, it executes:
remaining = len - (outptr - outbuf);
5. If "outptr" points past "outbuf + len", the arithmetics wraps around
and the variable "remaining" contains unusually high number
6. With "remaining" being high, the code writes more data past the end of
the buffer
Luckily, this bug has no security implications because:
1. Only root can issue device mapper ioctls
2. The commonly used libraries that communicate with device mapper
(libdevmapper and devicemapper-rs) use buffer size that is aligned to
8 bytes - thus, "outptr = align_ptr(outptr)" can't overshoot the input
buffer and the bug can't happen accidentally
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-08
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_uart: fix UAFs and race conditions in close and init paths
Vulnerabilities leading to Use-After-Free (UAF) and Null Pointer
Dereference (NPD) conditions were observed in the lifecycle management
of hci_uart.
The primary issue arises because the workqueues (init_ready and
write_work) are only flushed/cancelled if the HCI_UART_PROTO_READY
flag is set during TTY close. If a hangup occurs before setup completes,
hci_uart_tty_close() skips the teardown of these workqueues and
proceeds to free the `hu` struct. When the scheduled work executes
later, it blindly dereferences the freed `hu` struct.
Furthermore, several data races and UAFs were identified in the teardown
sequence:
1. Calling hci_uart_flush() from hci_uart_close() without effectively
disabling write_work causes a race condition where both can concurrently
double-free hu->tx_skb. This happens because protocol timers can
concurrently invoke hci_uart_tx_wakeup() and requeue write_work.
2. Calling hci_free_dev(hdev) before hu->proto->close(hu) causes a UAF
when vendor specific protocol close callbacks dereference hu->hdev.
3. In the initialization error paths, failing to take the proto_lock
write lock before clearing PROTO_READY leads to races with active
readers. Additionally, hci_uart_tty_receive() accesses hu->hdev
outside the read lock, leading to UAFs if the initialization error
path frees hdev concurrently.
Fix these synchronization and lifecycle issues by:
1. Re-ordering hci_uart_tty_close() to clear HCI_UART_PROTO_READY first,
followed immediately by a cancel_work_sync(&hu->write_work). Clearing
the flag locks out concurrent protocol timers from successfully invoking
hci_uart_tx_wakeup(), effectively rendering the cancellation permanent
and preventing the tx_skb double-free.
2. Note: Clearing PROTO_READY early causes hci_uart_close() to skip
hu->proto->flush(). This is perfectly safe in the tty_close path
because hu->proto->close() executes shortly after, which intrinsically
purges all protocol SKB queues and tears down the state.
3. Relocating hu->proto->close(hu) strictly prior to hci_free_dev(hdev)
across all close and error paths to prevent vendor-level UAFs.
4. Moving the hdev->stat.byte_rx increment in hci_uart_tty_receive()
inside the proto_lock read-side critical section to safely synchronize
with device unregistration.
5. Adding cancel_work_sync(&hu->write_work) to hci_uart_close() to safely
flush the workqueue before hci_uart_flush() is invoked via the HCI core.
6. Utilizing cancel_work_sync() instead of disable_work_sync() across
all paths to prevent permanently breaking user-space retry capabilities.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-06-08
In the Linux kernel, the following vulnerability has been resolved:
ibmveth: Disable GSO for packets with small MSS
Some physical adapters on Power systems do not support segmentation
offload when the MSS is less than 224 bytes. Attempting to send such
packets causes the adapter to freeze, stopping all traffic until
manually reset.
Implement ndo_features_check to disable GSO for packets with small MSS
values. The network stack will perform software segmentation instead.
The 224-byte minimum matches ibmvnic
commit <f10b09ef687f> ("ibmvnic: Enforce stronger sanity checks
on GSO packets")
which uses the same physical adapters in SEA configurations.
The issue occurs specifically when the hardware attempts to perform
segmentation (gso_segs > 1) with a small MSS. Single-segment GSO packets
(gso_segs == 1) do not trigger the problematic LSO code path and are
transmitted normally without segmentation.
Add an ndo_features_check callback to disable GSO when MSS < 224 bytes.
Also call vlan_features_check() to ensure proper handling of VLAN packets,
particularly QinQ (802.1ad) configurations where the hardware parser may
not support certain offload features.
Validated using iptables to force small MSS values. Without the fix,
the adapter freezes. With the fix, packets are segmented in software
and transmission succeeds. Comprehensive regression testing completedd
(MSS tests, performance, stability).
CVSS Score
8.6
EPSS Score
0.004
Published
2026-06-03
In the Linux kernel, the following vulnerability has been resolved:
inet: RAW sockets using IPPROTO_RAW MUST drop incoming ICMP
Yizhou Zhao reported that simply having one RAW socket on protocol
IPPROTO_RAW (255) was dangerous.
socket(AF_INET, SOCK_RAW, 255);
A malicious incoming ICMP packet can set the protocol field to 255
and match this socket, leading to FNHE cache changes.
inner = IP(src="192.168.2.1", dst="8.8.8.8", proto=255)/Raw("TEST")
pkt = IP(src="192.168.1.1", dst="192.168.2.1")/ICMP(type=3, code=4, nexthopmtu=576)/inner
"man 7 raw" states:
A protocol of IPPROTO_RAW implies enabled IP_HDRINCL and is able
to send any IP protocol that is specified in the passed header.
Receiving of all IP protocols via IPPROTO_RAW is not possible
using raw sockets.
Make sure we drop these malicious packets.
CVSS Score
9.1
EPSS Score
0.003
Published
2026-06-03
In the Linux kernel, the following vulnerability has been resolved:
nfc: hci: shdlc: Stop timers and work before freeing context
llc_shdlc_deinit() purges SHDLC skb queues and frees the llc_shdlc
structure while its timers and state machine work may still be active.
Timer callbacks can schedule sm_work, and sm_work accesses SHDLC state
and the skb queues. If teardown happens in parallel with a queued/running
work item, it can lead to UAF and other shutdown races.
Stop all SHDLC timers and cancel sm_work synchronously before purging the
queues and freeing the context.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-03