CVE-2026-53035

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

bpf, sockmap: Fix af_unix iter deadlock

bpf_iter_unix_seq_show() may deadlock when lock_sock_fast() takes the fast

path and the iter prog attempts to update a sockmap. Which ends up spinning

at sock_map_update_elem()'s bh_lock_sock():

WARNING: possible recursive locking detected

test_progs/1393 is trying to acquire lock:

ffff88811ec25f58 (slock-AF_UNIX){+...}-{3:3}, at: sock_map_update_elem+0xdb/0x1f0

but task is already holding lock:

ffff88811ec25f58 (slock-AF_UNIX){+...}-{3:3}, at: __lock_sock_fast+0x37/0xe0

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0

----

lock(slock-AF_UNIX);

lock(slock-AF_UNIX);

*** DEADLOCK ***

May be due to missing lock nesting notation

4 locks held by test_progs/1393:

#0: ffff88814b59c790 (&p->lock){+.+.}-{4:4}, at: bpf_seq_read+0x59/0x10d0

#1: ffff88811ec25fd8 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: bpf_seq_read+0x42c/0x10d0

#2: f

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References