| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
libceph: prevent potential out-of-bounds writes in handle_auth_session_key()
The len field originates from untrusted network packets. Boundary
checks have been added to prevent potential out-of-bounds writes when
decrypting the connection secret or processing service tickets.
[ idryomov: changelog ] |
| In the Linux kernel, the following vulnerability has been resolved:
libceph: replace BUG_ON with bounds check for map->max_osd
OSD indexes come from untrusted network packets. Boundary checks are
added to validate these against map->max_osd.
[ idryomov: drop BUG_ON in ceph_get_primary_affinity(), minor cosmetic
edits ] |
| In the Linux kernel, the following vulnerability has been resolved:
nvme: fix admin request_queue lifetime
The namespaces can access the controller's admin request_queue, and
stale references on the namespaces may exist after tearing down the
controller. Ensure the admin request_queue is active by moving the
controller's 'put' to after all controller references have been released
to ensure no one is can access the request_queue. This fixes a reported
use-after-free bug:
BUG: KASAN: slab-use-after-free in blk_queue_enter+0x41c/0x4a0
Read of size 8 at addr ffff88c0a53819f8 by task nvme/3287
CPU: 67 UID: 0 PID: 3287 Comm: nvme Tainted: G E 6.13.2-ga1582f1a031e #15
Tainted: [E]=UNSIGNED_MODULE
Hardware name: Jabil /EGS 2S MB1, BIOS 1.00 06/18/2025
Call Trace:
<TASK>
dump_stack_lvl+0x4f/0x60
print_report+0xc4/0x620
? _raw_spin_lock_irqsave+0x70/0xb0
? _raw_read_unlock_irqrestore+0x30/0x30
? blk_queue_enter+0x41c/0x4a0
kasan_report+0xab/0xe0
? blk_queue_enter+0x41c/0x4a0
blk_queue_enter+0x41c/0x4a0
? __irq_work_queue_local+0x75/0x1d0
? blk_queue_start_drain+0x70/0x70
? irq_work_queue+0x18/0x20
? vprintk_emit.part.0+0x1cc/0x350
? wake_up_klogd_work_func+0x60/0x60
blk_mq_alloc_request+0x2b7/0x6b0
? __blk_mq_alloc_requests+0x1060/0x1060
? __switch_to+0x5b7/0x1060
nvme_submit_user_cmd+0xa9/0x330
nvme_user_cmd.isra.0+0x240/0x3f0
? force_sigsegv+0xe0/0xe0
? nvme_user_cmd64+0x400/0x400
? vfs_fileattr_set+0x9b0/0x9b0
? cgroup_update_frozen_flag+0x24/0x1c0
? cgroup_leave_frozen+0x204/0x330
? nvme_ioctl+0x7c/0x2c0
blkdev_ioctl+0x1a8/0x4d0
? blkdev_common_ioctl+0x1930/0x1930
? fdget+0x54/0x380
__x64_sys_ioctl+0x129/0x190
do_syscall_64+0x5b/0x160
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f765f703b0b
Code: ff ff ff 85 c0 79 9b 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d dd 52 0f 00 f7 d8 64 89 01 48
RSP: 002b:00007ffe2cefe808 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffe2cefe860 RCX: 00007f765f703b0b
RDX: 00007ffe2cefe860 RSI: 00000000c0484e41 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000
R10: 00007f765f611d50 R11: 0000000000000202 R12: 0000000000000003
R13: 00000000c0484e41 R14: 0000000000000001 R15: 00007ffe2cefea60
</TASK> |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: add i_data_sem protection in ext4_destroy_inline_data_nolock()
Fix a race between inline data destruction and block mapping.
The function ext4_destroy_inline_data_nolock() changes the inode data
layout by clearing EXT4_INODE_INLINE_DATA and setting EXT4_INODE_EXTENTS.
At the same time, another thread may execute ext4_map_blocks(), which
tests EXT4_INODE_EXTENTS to decide whether to call ext4_ext_map_blocks()
or ext4_ind_map_blocks().
Without i_data_sem protection, ext4_ind_map_blocks() may receive inode
with EXT4_INODE_EXTENTS flag and triggering assert.
kernel BUG at fs/ext4/indirect.c:546!
EXT4-fs (loop2): unmounting filesystem.
invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:ext4_ind_map_blocks.cold+0x2b/0x5a fs/ext4/indirect.c:546
Call Trace:
<TASK>
ext4_map_blocks+0xb9b/0x16f0 fs/ext4/inode.c:681
_ext4_get_block+0x242/0x590 fs/ext4/inode.c:822
ext4_block_write_begin+0x48b/0x12c0 fs/ext4/inode.c:1124
ext4_write_begin+0x598/0xef0 fs/ext4/inode.c:1255
ext4_da_write_begin+0x21e/0x9c0 fs/ext4/inode.c:3000
generic_perform_write+0x259/0x5d0 mm/filemap.c:3846
ext4_buffered_write_iter+0x15b/0x470 fs/ext4/file.c:285
ext4_file_write_iter+0x8e0/0x17f0 fs/ext4/file.c:679
call_write_iter include/linux/fs.h:2271 [inline]
do_iter_readv_writev+0x212/0x3c0 fs/read_write.c:735
do_iter_write+0x186/0x710 fs/read_write.c:861
vfs_iter_write+0x70/0xa0 fs/read_write.c:902
iter_file_splice_write+0x73b/0xc90 fs/splice.c:685
do_splice_from fs/splice.c:763 [inline]
direct_splice_actor+0x10f/0x170 fs/splice.c:950
splice_direct_to_actor+0x33a/0xa10 fs/splice.c:896
do_splice_direct+0x1a9/0x280 fs/splice.c:1002
do_sendfile+0xb13/0x12c0 fs/read_write.c:1255
__do_sys_sendfile64 fs/read_write.c:1323 [inline]
__se_sys_sendfile64 fs/read_write.c:1309 [inline]
__x64_sys_sendfile64+0x1cf/0x210 fs/read_write.c:1309
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x6e/0xd8 |
| In the Linux kernel, the following vulnerability has been resolved:
rust_binder: fix race condition on death_list
Rust Binder contains the following unsafe operation:
// SAFETY: A `NodeDeath` is never inserted into the death list
// of any node other than its owner, so it is either in this
// death list or in no death list.
unsafe { node_inner.death_list.remove(self) };
This operation is unsafe because when touching the prev/next pointers of
a list element, we have to ensure that no other thread is also touching
them in parallel. If the node is present in the list that `remove` is
called on, then that is fine because we have exclusive access to that
list. If the node is not in any list, then it's also ok. But if it's
present in a different list that may be accessed in parallel, then that
may be a data race on the prev/next pointers.
And unfortunately that is exactly what is happening here. In
Node::release, we:
1. Take the lock.
2. Move all items to a local list on the stack.
3. Drop the lock.
4. Iterate the local list on the stack.
Combined with threads using the unsafe remove method on the original
list, this leads to memory corruption of the prev/next pointers. This
leads to crashes like this one:
Unable to handle kernel paging request at virtual address 000bb9841bcac70e
Mem abort info:
ESR = 0x0000000096000044
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
Data abort info:
ISV = 0, ISS = 0x00000044, ISS2 = 0x00000000
CM = 0, WnR = 1, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[000bb9841bcac70e] address between user and kernel address ranges
Internal error: Oops: 0000000096000044 [#1] PREEMPT SMP
google-cdd 538c004.gcdd: context saved(CPU:1)
item - log_kevents is disabled
Modules linked in: ... rust_binder
CPU: 1 UID: 0 PID: 2092 Comm: kworker/1:178 Tainted: G S W OE 6.12.52-android16-5-g98debd5df505-4k #1 f94a6367396c5488d635708e43ee0c888d230b0b
Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: MUSTANG PVT 1.0 based on LGA (DT)
Workqueue: events _RNvXs6_NtCsdfZWD8DztAw_6kernel9workqueueINtNtNtB7_4sync3arc3ArcNtNtCs8QPsHWIn21X_16rust_binder_main7process7ProcessEINtB5_15WorkItemPointerKy0_E3runB13_ [rust_binder]
pstate: 23400005 (nzCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : _RNvXs3_NtCs8QPsHWIn21X_16rust_binder_main7processNtB5_7ProcessNtNtCsdfZWD8DztAw_6kernel9workqueue8WorkItem3run+0x450/0x11f8 [rust_binder]
lr : _RNvXs3_NtCs8QPsHWIn21X_16rust_binder_main7processNtB5_7ProcessNtNtCsdfZWD8DztAw_6kernel9workqueue8WorkItem3run+0x464/0x11f8 [rust_binder]
sp : ffffffc09b433ac0
x29: ffffffc09b433d30 x28: ffffff8821690000 x27: ffffffd40cbaa448
x26: ffffff8821690000 x25: 00000000ffffffff x24: ffffff88d0376578
x23: 0000000000000001 x22: ffffffc09b433c78 x21: ffffff88e8f9bf40
x20: ffffff88e8f9bf40 x19: ffffff882692b000 x18: ffffffd40f10bf00
x17: 00000000c006287d x16: 00000000c006287d x15: 00000000000003b0
x14: 0000000000000100 x13: 000000201cb79ae0 x12: fffffffffffffff0
x11: 0000000000000000 x10: 0000000000000001 x9 : 0000000000000000
x8 : b80bb9841bcac706 x7 : 0000000000000001 x6 : fffffffebee63f30
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000004c31 x1 : ffffff88216900c0 x0 : ffffff88e8f9bf00
Call trace:
_RNvXs3_NtCs8QPsHWIn21X_16rust_binder_main7processNtB5_7ProcessNtNtCsdfZWD8DztAw_6kernel9workqueue8WorkItem3run+0x450/0x11f8 [rust_binder bbc172b53665bbc815363b22e97e3f7e3fe971fc]
process_scheduled_works+0x1c4/0x45c
worker_thread+0x32c/0x3e8
kthread+0x11c/0x1c8
ret_from_fork+0x10/0x20
Code: 94218d85 b4000155 a94026a8 d10102a0 (f9000509)
---[ end trace 0000000000000000 ]---
Thus, modify Node::release to pop items directly off the original list. |
| In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix out-of-bounds read in rtw_get_ie() parser
The Information Element (IE) parser rtw_get_ie() trusted the length
byte of each IE without validating that the IE body (len bytes after
the 2-byte header) fits inside the remaining frame buffer. A malformed
frame can advertise an IE length larger than the available data, causing
the parser to increment its pointer beyond the buffer end. This results
in out-of-bounds reads or, depending on the pattern, an infinite loop.
Fix by validating that (offset + 2 + len) does not exceed the limit
before accepting the IE or advancing to the next element.
This prevents OOB reads and ensures the parser terminates safely on
malformed frames. |
| In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix stack buffer overflow in OnAssocReq IE parsing
The Supported Rates IE length from an incoming Association Request frame
was used directly as the memcpy() length when copying into a fixed-size
16-byte stack buffer (supportRate). A malicious station can advertise an
IE length larger than 16 bytes, causing a stack buffer overflow.
Clamp ie_len to the buffer size before copying the Supported Rates IE,
and correct the bounds check when merging Extended Supported Rates to
prevent a second potential overflow.
This prevents kernel stack corruption triggered by malformed association
requests. |
| In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix out-of-bounds read in OnBeacon ESR IE parsing
The Extended Supported Rates (ESR) IE handling in OnBeacon accessed
*(p + 1 + ielen) and *(p + 2 + ielen) without verifying that these
offsets lie within the received frame buffer. A malformed beacon with
an ESR IE positioned at the end of the buffer could cause an
out-of-bounds read, potentially triggering a kernel panic.
Add a boundary check to ensure that the ESR IE body and the subsequent
bytes are within the limits of the frame before attempting to access
them.
This prevents OOB reads caused by malformed beacon frames. |
| In the Linux kernel, the following vulnerability has been resolved:
hung_task: fix warnings caused by unaligned lock pointers
The blocker tracking mechanism assumes that lock pointers are at least
4-byte aligned to use their lower bits for type encoding.
However, as reported by Eero Tamminen, some architectures like m68k
only guarantee 2-byte alignment of 32-bit values. This breaks the
assumption and causes two related WARN_ON_ONCE checks to trigger.
To fix this, the runtime checks are adjusted to silently ignore any lock
that is not 4-byte aligned, effectively disabling the feature in such
cases and avoiding the related warnings.
Thanks to Geert Uytterhoeven for bisecting! |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: close accepted socket when per-IP limit rejects connection
When the per-IP connection limit is exceeded in ksmbd_kthread_fn(),
the code sets ret = -EAGAIN and continues the accept loop without
closing the just-accepted socket. That leaks one socket per rejected
attempt from a single IP and enables a trivial remote DoS.
Release client_sk before continuing.
This bug was found with ZeroPath. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv4: route: Prevent rt_bind_exception() from rebinding stale fnhe
The sit driver's packet transmission path calls: sit_tunnel_xmit() ->
update_or_create_fnhe(), which lead to fnhe_remove_oldest() being called
to delete entries exceeding FNHE_RECLAIM_DEPTH+random.
The race window is between fnhe_remove_oldest() selecting fnheX for
deletion and the subsequent kfree_rcu(). During this time, the
concurrent path's __mkroute_output() -> find_exception() can fetch the
soon-to-be-deleted fnheX, and rt_bind_exception() then binds it with a
new dst using a dst_hold(). When the original fnheX is freed via RCU,
the dst reference remains permanently leaked.
CPU 0 CPU 1
__mkroute_output()
find_exception() [fnheX]
update_or_create_fnhe()
fnhe_remove_oldest() [fnheX]
rt_bind_exception() [bind dst]
RCU callback [fnheX freed, dst leak]
This issue manifests as a device reference count leak and a warning in
dmesg when unregistering the net device:
unregister_netdevice: waiting for sitX to become free. Usage count = N
Ido Schimmel provided the simple test validation method [1].
The fix clears 'oldest->fnhe_daddr' before calling fnhe_flush_routes().
Since rt_bind_exception() checks this field, setting it to zero prevents
the stale fnhe from being reused and bound to a new dst just before it
is freed.
[1]
ip netns add ns1
ip -n ns1 link set dev lo up
ip -n ns1 address add 192.0.2.1/32 dev lo
ip -n ns1 link add name dummy1 up type dummy
ip -n ns1 route add 192.0.2.2/32 dev dummy1
ip -n ns1 link add name gretap1 up arp off type gretap \
local 192.0.2.1 remote 192.0.2.2
ip -n ns1 route add 198.51.0.0/16 dev gretap1
taskset -c 0 ip netns exec ns1 mausezahn gretap1 \
-A 198.51.100.1 -B 198.51.0.0/16 -t udp -p 1000 -c 0 -q &
taskset -c 2 ip netns exec ns1 mausezahn gretap1 \
-A 198.51.100.1 -B 198.51.0.0/16 -t udp -p 1000 -c 0 -q &
sleep 10
ip netns pids ns1 | xargs kill
ip netns del ns1 |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring/cmd_net: fix wrong argument types for skb_queue_splice()
If timestamp retriving needs to be retried and the local list of
SKB's already has entries, then it's spliced back into the socket
queue. However, the arguments for the splice helper are transposed,
causing exactly the wrong direction of splicing into the on-stack
list. Fix that up. |
| In the Linux kernel, the following vulnerability has been resolved:
veth: more robust handing of race to avoid txq getting stuck
Commit dc82a33297fc ("veth: apply qdisc backpressure on full ptr_ring to
reduce TX drops") introduced a race condition that can lead to a permanently
stalled TXQ. This was observed in production on ARM64 systems (Ampere Altra
Max).
The race occurs in veth_xmit(). The producer observes a full ptr_ring and
stops the queue (netif_tx_stop_queue()). The subsequent conditional logic,
intended to re-wake the queue if the consumer had just emptied it (if
(__ptr_ring_empty(...)) netif_tx_wake_queue()), can fail. This leads to a
"lost wakeup" where the TXQ remains stopped (QUEUE_STATE_DRV_XOFF) and
traffic halts.
This failure is caused by an incorrect use of the __ptr_ring_empty() API
from the producer side. As noted in kernel comments, this check is not
guaranteed to be correct if a consumer is operating on another CPU. The
empty test is based on ptr_ring->consumer_head, making it reliable only for
the consumer. Using this check from the producer side is fundamentally racy.
This patch fixes the race by adopting the more robust logic from an earlier
version V4 of the patchset, which always flushed the peer:
(1) In veth_xmit(), the racy conditional wake-up logic and its memory barrier
are removed. Instead, after stopping the queue, we unconditionally call
__veth_xdp_flush(rq). This guarantees that the NAPI consumer is scheduled,
making it solely responsible for re-waking the TXQ.
This handles the race where veth_poll() consumes all packets and completes
NAPI *before* veth_xmit() on the producer side has called netif_tx_stop_queue.
The __veth_xdp_flush(rq) will observe rx_notify_masked is false and schedule
NAPI.
(2) On the consumer side, the logic for waking the peer TXQ is moved out of
veth_xdp_rcv() and placed at the end of the veth_poll() function. This
placement is part of fixing the race, as the netif_tx_queue_stopped() check
must occur after rx_notify_masked is potentially set to false during NAPI
completion.
This handles the race where veth_poll() consumes all packets, but haven't
finished (rx_notify_masked is still true). The producer veth_xmit() stops the
TXQ and __veth_xdp_flush(rq) will observe rx_notify_masked is true, meaning
not starting NAPI. Then veth_poll() change rx_notify_masked to false and
stops NAPI. Before exiting veth_poll() will observe TXQ is stopped and wake
it up. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix incomplete backport in cfids_invalidation_worker()
The previous commit bdb596ceb4b7 ("smb: client: fix potential UAF in
smb2_close_cached_fid()") was an incomplete backport and missed one
kref_put() call in cfids_invalidation_worker() that should have been
converted to close_cached_dir(). |
| In the Linux kernel, the following vulnerability has been resolved:
nvme-multipath: fix lockdep WARN due to partition scan work
Blktests test cases nvme/014, 057 and 058 fail occasionally due to a
lockdep WARN. As reported in the Closes tag URL, the WARN indicates that
a deadlock can happen due to the dependency among disk->open_mutex,
kblockd workqueue completion and partition_scan_work completion.
To avoid the lockdep WARN and the potential deadlock, cut the dependency
by running the partition_scan_work not by kblockd workqueue but by
nvme_wq. |
| In the Linux kernel, the following vulnerability has been resolved:
fs: Fix uninitialized 'offp' in statmount_string()
In statmount_string(), most flags assign an output offset pointer (offp)
which is later updated with the string offset. However, the
STATMOUNT_MNT_UIDMAP and STATMOUNT_MNT_GIDMAP cases directly set the
struct fields instead of using offp. This leaves offp uninitialized,
leading to a possible uninitialized dereference when *offp is updated.
Fix it by assigning offp for UIDMAP and GIDMAP as well, keeping the code
path consistent. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: account for current allocated stack depth in widen_imprecise_scalars()
The usage pattern for widen_imprecise_scalars() looks as follows:
prev_st = find_prev_entry(env, ...);
queued_st = push_stack(...);
widen_imprecise_scalars(env, prev_st, queued_st);
Where prev_st is an ancestor of the queued_st in the explored states
tree. This ancestor is not guaranteed to have same allocated stack
depth as queued_st. E.g. in the following case:
def main():
for i in 1..2:
foo(i) // same callsite, differnt param
def foo(i):
if i == 1:
use 128 bytes of stack
iterator based loop
Here, for a second 'foo' call prev_st->allocated_stack is 128,
while queued_st->allocated_stack is much smaller.
widen_imprecise_scalars() needs to take this into account and avoid
accessing bpf_verifier_state->frame[*]->stack out of bounds. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/guc: Synchronize Dead CT worker with unbind
Cancel and wait for any Dead CT worker to complete before continuing
with device unbinding. Else the worker will end up using resources freed
by the undind operation.
(cherry picked from commit 492671339114e376aaa38626d637a2751cdef263) |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_ct: add seqadj extension for natted connections
Sequence adjustment may be required for FTP traffic with PASV/EPSV modes.
due to need to re-write packet payload (IP, port) on the ftp control
connection. This can require changes to the TCP length and expected
seq / ack_seq.
The easiest way to reproduce this issue is with PASV mode.
Example ruleset:
table inet ftp_nat {
ct helper ftp_helper {
type "ftp" protocol tcp
l3proto inet
}
chain prerouting {
type filter hook prerouting priority 0; policy accept;
tcp dport 21 ct state new ct helper set "ftp_helper"
}
}
table ip nat {
chain prerouting {
type nat hook prerouting priority -100; policy accept;
tcp dport 21 dnat ip prefix to ip daddr map {
192.168.100.1 : 192.168.13.2/32 }
}
chain postrouting {
type nat hook postrouting priority 100 ; policy accept;
tcp sport 21 snat ip prefix to ip saddr map {
192.168.13.2 : 192.168.100.1/32 }
}
}
Note that the ftp helper gets assigned *after* the dnat setup.
The inverse (nat after helper assign) is handled by an existing
check in nf_nat_setup_info() and will not show the problem.
Topoloy:
+-------------------+ +----------------------------------+
| FTP: 192.168.13.2 | <-> | NAT: 192.168.13.3, 192.168.100.1 |
+-------------------+ +----------------------------------+
|
+-----------------------+
| Client: 192.168.100.2 |
+-----------------------+
ftp nat changes do not work as expected in this case:
Connected to 192.168.100.1.
[..]
ftp> epsv
EPSV/EPRT on IPv4 off.
ftp> ls
227 Entering passive mode (192,168,100,1,209,129).
421 Service not available, remote server has closed connection.
Kernel logs:
Missing nfct_seqadj_ext_add() setup call
WARNING: CPU: 1 PID: 0 at net/netfilter/nf_conntrack_seqadj.c:41
[..]
__nf_nat_mangle_tcp_packet+0x100/0x160 [nf_nat]
nf_nat_ftp+0x142/0x280 [nf_nat_ftp]
help+0x4d1/0x880 [nf_conntrack_ftp]
nf_confirm+0x122/0x2e0 [nf_conntrack]
nf_hook_slow+0x3c/0xb0
..
Fix this by adding the required extension when a conntrack helper is assigned
to a connection that has a nat binding. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/CPU/AMD: Add missing terminator for zen5_rdseed_microcode
Running x86_match_min_microcode_rev() on a Zen5 CPU trips up KASAN for an out
of bounds access. |