Linux: >> Linux Kernel >> 4.14.285 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
net/rds: Clear reconnect pending bit
When canceling the reconnect worker, care must be taken to reset the
reconnect-pending bit. If the reconnect worker has not yet been
scheduled before it is canceled, the reconnect-pending bit will stay
on forever.
CVSS Score
7.5
EPSS Score
0.001
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
net: Drop the lock in skb_may_tx_timestamp()
skb_may_tx_timestamp() may acquire sock::sk_callback_lock. The lock must
not be taken in IRQ context, only softirq is okay. A few drivers receive
the timestamp via a dedicated interrupt and complete the TX timestamp
from that handler. This will lead to a deadlock if the lock is already
write-locked on the same CPU.
Taking the lock can be avoided. The socket (pointed by the skb) will
remain valid until the skb is released. The ->sk_socket and ->file
member will be set to NULL once the user closes the socket which may
happen before the timestamp arrives.
If we happen to observe the pointer while the socket is closing but
before the pointer is set to NULL then we may use it because both
pointer (and the file's cred member) are RCU freed.
Drop the lock. Use READ_ONCE() to obtain the individual pointer. Add a
matching WRITE_ONCE() where the pointer are cleared.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
media: i2c/tw9903: Fix potential memory leak in tw9903_probe()
In one of the error paths in tw9903_probe(), the memory allocated in
v4l2_ctrl_handler_init() and v4l2_ctrl_new_std() is not freed. Fix that
by calling v4l2_ctrl_handler_free() on the handler in that error path.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
media: mtk-mdp: Fix error handling in probe function
Add mtk_mdp_unregister_m2m_device() on the error handling path to prevent
resource leak.
Add check for the return value of vpu_get_plat_device() to prevent null
pointer dereference. And vpu_get_plat_device() increases the reference
count of the returned platform device. Add platform_device_put() to
prevent reference leak.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
minix: Add required sanity checking to minix_check_superblock()
The fs/minix implementation of the minix filesystem does not currently
support any other value for s_log_zone_size than 0. This is also the
only value supported in util-linux; see mkfs.minix.c line 511. In
addition, this patch adds some sanity checking for the other minix
superblock fields, and moves the minix_blocks_needed() checks for the
zmap and imap also to minix_check_super_block().
This also closes a related syzbot bug report.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
fbdev: vt8500lcdfb: fix missing dma_free_coherent()
fbi->fb.screen_buffer is allocated with dma_alloc_coherent() but is not
freed if the error path is reached.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
atm: fore200e: fix use-after-free in tasklets during device removal
When the PCA-200E or SBA-200E adapter is being detached, the fore200e
is deallocated. However, the tx_tasklet or rx_tasklet may still be running
or pending, leading to use-after-free bug when the already freed fore200e
is accessed again in fore200e_tx_tasklet() or fore200e_rx_tasklet().
One of the race conditions can occur as follows:
CPU 0 (cleanup) | CPU 1 (tasklet)
fore200e_pca_remove_one() | fore200e_interrupt()
fore200e_shutdown() | tasklet_schedule()
kfree(fore200e) | fore200e_tx_tasklet()
| fore200e-> // UAF
Fix this by ensuring tx_tasklet or rx_tasklet is properly canceled before
the fore200e is released. Add tasklet_kill() in fore200e_shutdown() to
synchronize with any pending or running tasklets. Moreover, since
fore200e_reset() could prevent further interrupts or data transfers,
the tasklet_kill() should be placed after fore200e_reset() to prevent
the tasklet from being rescheduled in fore200e_interrupt(). Finally,
it only needs to do tasklet_kill() when the fore200e state is greater
than or equal to FORE200E_STATE_IRQ, since tasklets are uninitialized
in earlier states. In a word, the tasklet_kill() should be placed in
the FORE200E_STATE_IRQ branch within the switch...case structure.
This bug was identified through static analysis.
CVSS Score
7.5
EPSS Score
0.001
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
net: consume xmit errors of GSO frames
udpgro_frglist.sh and udpgro_bench.sh are the flakiest tests
currently in NIPA. They fail in the same exact way, TCP GRO
test stalls occasionally and the test gets killed after 10min.
These tests use veth to simulate GRO. They attach a trivial
("return XDP_PASS;") XDP program to the veth to force TSO off
and NAPI on.
Digging into the failure mode we can see that the connection
is completely stuck after a burst of drops. The sender's snd_nxt
is at sequence number N [1], but the receiver claims to have
received (rcv_nxt) up to N + 3 * MSS [2]. Last piece of the puzzle
is that senders rtx queue is not empty (let's say the block in
the rtx queue is at sequence number N - 4 * MSS [3]).
In this state, sender sends a retransmission from the rtx queue
with a single segment, and sequence numbers N-4*MSS:N-3*MSS [3].
Receiver sees it and responds with an ACK all the way up to
N + 3 * MSS [2]. But sender will reject this ack as TCP_ACK_UNSENT_DATA
because it has no recollection of ever sending data that far out [1].
And we are stuck.
The root cause is the mess of the xmit return codes. veth returns
an error when it can't xmit a frame. We end up with a loss event
like this:
-------------------------------------------------
| GSO super frame 1 | GSO super frame 2 |
|-----------------------------------------------|
| seg | seg | seg | seg | seg | seg | seg | seg |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
-------------------------------------------------
x ok ok <ok>| ok ok ok <x>
\\
snd_nxt
"x" means packet lost by veth, and "ok" means it went thru.
Since veth has TSO disabled in this test it sees individual segments.
Segment 1 is on the retransmit queue and will be resent.
So why did the sender not advance snd_nxt even tho it clearly did
send up to seg 8? tcp_write_xmit() interprets the return code
from the core to mean that data has not been sent at all. Since
TCP deals with GSO super frames, not individual segment the crux
of the problem is that loss of a single segment can be interpreted
as loss of all. TCP only sees the last return code for the last
segment of the GSO frame (in <> brackets in the diagram above).
Of course for the problem to occur we need a setup or a device
without a Qdisc. Otherwise Qdisc layer disconnects the protocol
layer from the device errors completely.
We have multiple ways to fix this.
1) make veth not return an error when it lost a packet.
While this is what I think we did in the past, the issue keeps
reappearing and it's annoying to debug. The game of whack
a mole is not great.
2) fix the damn return codes
We only talk about NETDEV_TX_OK and NETDEV_TX_BUSY in the
documentation, so maybe we should make the return code from
ndo_start_xmit() a boolean. I like that the most, but perhaps
some ancient, not-really-networking protocol would suffer.
3) make TCP ignore the errors
It is not entirely clear to me what benefit TCP gets from
interpreting the result of ip_queue_xmit()? Specifically once
the connection is established and we're pushing data - packet
loss is just packet loss?
4) this fix
Ignore the rc in the Qdisc-less+GSO case, since it's unreliable.
We already always return OK in the TCQ_F_CAN_BYPASS case.
In the Qdisc-less case let's be a bit more conservative and only
mask the GSO errors. This path is taken by non-IP-"networks"
like CAN, MCTP etc, so we could regress some ancient thing.
This is the simplest, but also maybe the hackiest fix?
Similar fix has been proposed by Eric in the past but never committed
because original reporter was working with an OOT driver and wasn't
providing feedback (see Link).
CVSS Score
7.5
EPSS Score
0.001
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
tcp: fix potential race in tcp_v6_syn_recv_sock()
Code in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock()
is done too late.
After tcp_v4_syn_recv_sock(), the child socket is already visible
from TCP ehash table and other cpus might use it.
Since newinet->pinet6 is still pointing to the listener ipv6_pinfo
bad things can happen as syzbot found.
Move the problematic code in tcp_v6_mapped_child_init()
and call this new helper from tcp_v4_syn_recv_sock() before
the ehash insertion.
This allows the removal of one tcp_sync_mss(), since
tcp_v4_syn_recv_sock() will call it with the correct
context.
CVSS Score
9.8
EPSS Score
0.001
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
xfs: delete attr leaf freemap entries when empty
Back in commit 2a2b5932db6758 ("xfs: fix attr leaf header freemap.size
underflow"), Brian Foster observed that it's possible for a small
freemap at the end of the end of the xattr entries array to experience
a size underflow when subtracting the space consumed by an expansion of
the entries array. There are only three freemap entries, which means
that it is not a complete index of all free space in the leaf block.
This code can leave behind a zero-length freemap entry with a nonzero
base. Subsequent setxattr operations can increase the base up to the
point that it overlaps with another freemap entry. This isn't in and of
itself a problem because the code in _leaf_add that finds free space
ignores any freemap entry with zero size.
However, there's another bug in the freemap update code in _leaf_add,
which is that it fails to update a freemap entry that begins midway
through the xattr entry that was just appended to the array. That can
result in the freemap containing two entries with the same base but
different sizes (0 for the "pushed-up" entry, nonzero for the entry
that's actually tracking free space). A subsequent _leaf_add can then
allocate xattr namevalue entries on top of the entries array, leading to
data loss. But fixing that is for later.
For now, eliminate the possibility of confusion by zeroing out the base
of any freemap entry that has zero size. Because the freemap is not
intended to be a complete index of free space, a subsequent failure to
find any free space for a new xattr will trigger block compaction, which
regenerates the freemap.
It looks like this bug has been in the codebase for quite a long time.
CVSS Score
8.8
EPSS Score
0.001
Published
2026-05-06