CVE-2026-53035: bpf, sockmap: Fix af_unix iter deadlock
Vulnerability summary
CVE-2026-53035 is a medium (CVSS 5.5) Improper Locking vulnerability in linux. EPSS estimates a 0.10% chance of exploitation in the next 30 days, higher than 0.5% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 37 · Related 37Timeline
- 24-06-2026PublishedVulnerability first disclosed.
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: ffff88811ec25f58 (slock-AF_UNIX){+...}-{3:3}, at: __lock_sock_fast+0x37/0xe0 #3: ffffffff85a6a7c0 (rcu_read_lock){....}-{1:3}, at: bpf_iter_run_prog+0x51d/0xb00 Call Trace: dump_stack_lvl+0x5d/0x80 print_deadlock_bug.cold+0xc0/0xce __lock_acquire+0x130f/0x2590 lock_acquire+0x14e/0x2b0 _raw_spin_lock+0x30/0x40 sock_map_update_elem+0xdb/0x1f0 bpf_prog_2d0075e5d9b721cd_dump_unix+0x55/0x4f4 bpf_iter_run_prog+0x5b9/0xb00 bpf_iter_unix_seq_show+0x1f7/0x2e0 bpf_seq_read+0x42c/0x10d0 vfs_read+0x171/0xb20 ksys_read+0xff/0x200 do_syscall_64+0x6b/0x3a0 entry_SYSCALL_64_after_hwframe+0x76/0x7e
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.10%
Chance of exploitation in the next 30 days
Percentile
1%
Versus all other CVEs
30-day change
Decrease -0.03 pp
From 0.13% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu154 products
- linuxAll versions (No fix recorded) | < 6.8.0-136.136 | < 7.0.0-28.28
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 6.8.0-1061.64 | < 7.0.0-1009.9
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 2c860a43dd77f969bb959336a2f743d7103a8f63, < bd3592129f24243713673a07225cf1f15a9bb835 | ≥ 2c860a43dd77f969bb959336a2f743d7103a8f63, < 3cef33b9813b78f227942572fb317afcd5c9ac94 | ≥ 2c860a43dd77f969bb959336a2f743d7103a8f63, < 87828b380956d4986f59f2c086e0b09b3e6cdaae | ≥ 2c860a43dd77f969bb959336a2f743d7103a8f63, < 527057ebe8076dfbcaef51195ff1b7508646be2c | ≥ 2c860a43dd77f969bb959336a2f743d7103a8f63, < 66d9fab4565eafe1afe7ba0581f79b76073b60fa | ≥ 2c860a43dd77f969bb959336a2f743d7103a8f63, < 4d328dd695383224aa750ddee6b4ad40c0f8d205 | 5.15
- linux_kernel≥ 5.15, < 6.1.175 | ≥ 6.2, < 6.6.141 | ≥ 6.7, < 6.12.91 | ≥ 6.13, < 6.18.33 | ≥ 6.19, < 7.0.10
Debian1 product
- linux< 6.1.176-1 | < 6.12.94-1 | < 7.0.10-1
3 vendors · 157 products
