CVE-2023-53857 — bpf: bpf_sk_storage: Fix invalid wait context lockdep report
In the Linux kernel, the following vulnerability has been resolved: bpf: bpf_sk_storage: Fix invalid wait context lockdep report './test_progs -t test_local_storage' reported a splat: [ 27.137569] ============================= [ 27.138122] [ BUG: Invalid wait context ] [ 27.138650] 6.5.0-03980-gd11ae1b16b0a #247 Tainted: G O [ 27.139542] ----------------------------- [ 27.140106] test_progs/1729 is trying to lock: [ 27.140713] ffff8883ef047b88 (stock_lock){-.-.}-{3:3}, at: local_lock_acquire+0x9/0x130 [ 27.141834] other info that might help us debug this: [ 27.142437] context-{5:5} [ 27.142856] 2 locks held by test_progs/1729: [ 27.143352] #0: ffffffff84bcd9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x40 [ 27.144492] #1: ffff888107deb2c0 (&storage->lock){..-.}-{2:2}, at: bpf_local_storage_update+0x39e/0x8e0 [ 27.145855] stack backtrace: [ 27.146274] CPU: 0 PID: 1729 Comm: test_progs Tainted: G O 6.5.0-03980-gd11ae1b16b0a #247 [ 27.147550] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 27.149127] Call Trace: [ 27.149490] <TASK> [ 27.149867] dump_stack_lvl+0x130/0x1d0 [ 27.152609] dump_stack+0x14/0x20 [ 27.153131] __lock_acquire+0x1657/0x2220 [ 27.153677] lock_acquire+0x1b8/0x510 [ 27.157908] local_lock_acquire+0x29/0x130 [ 27.159048] obj_cgroup_charge+0xf4/0x3c0 [ 27.160794] slab_pre_alloc_hook+0x28e/0x2b0 [ 27.161931] __kmem_cache_alloc_node+0x51/0x210 [ 27.163557] __kmalloc+0xaa/0x210 [ 27.164593] bpf_map_kzalloc+0xbc/0x170 [ 27.165147] bpf_selem_alloc+0x130/0x510 [ 27.166295] bpf_local_storage_update+0x5aa/0x8e0 [ 27.167042] bpf_fd_sk_storage_update_elem+0xdb/0x1a0 [ 27.169199] bpf_map_update_value+0x415/0x4f0 [ 27.169871] map_update_elem+0x413/0x550 [ 27.170330] __sys_bpf+0x5e9/0x640 [ 27.174065] __x64_sys_bpf+0x80/0x90 [ 27.174568] do_syscall_64+0x48/0xa0 [ 27.175201] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 27.175932] RIP: 0033:0x7effb40e41ad [ 27.176357] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d8 [ 27.179028] RSP: 002b:00007ffe64c21fc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000141 [ 27.180088] RAX: ffffffffffffffda RBX: 00007ffe64c22768 RCX: 00007effb40e41ad [ 27.181082] RDX: 0000000000000020 RSI: 00007ffe64c22008 RDI: 0000000000000002 [ 27.182030] RBP: 00007ffe64c21ff0 R08: 0000000000000000 R09: 00007ffe64c22788 [ 27.183038] R10: 0000000000000064 R11: 0000000000000202 R12: 0000000000000000 [ 27.184006] R13: 00007ffe64c22788 R14: 00007effb42a1000 R15: 0000000000000000 [ 27.184958] </TASK> It complains about acquiring a local_lock while holding a raw_spin_lock. It means it should not allocate memory while holding a raw_spin_lock since it is not safe for RT. raw_spin_lock is needed because bpf_local_storage supports tracing context. In particular for task local storage, it is easy to get a "current" task PTR_TO_BTF_ID in tracing bpf prog. However, task (and cgroup) local storage has already been moved to bpf mem allocator which can be used after raw_spin_lock. The splat is for the sk storage. For sk (and inode) storage, it has not been moved to bpf mem allocator. Using raw_spin_lock or not, kzalloc(GFP_ATOMIC) could theoretically be unsafe in tracing context. However, the local storage helper requires a verifier accepted sk pointer (PTR_TO_BTF_ID), it is hypothetical if that (mean running a bpf prog in a kzalloc unsafe context and also able to hold a verifier accepted sk pointer) could happen. This patch avoids kzalloc after raw_spin_lock to silent the splat. There is an existing kzalloc before the raw_spin_lock. At that point, a kzalloc is very likely required because a lookup has just been done before. Thus, this patch always does the kzalloc before acq ---truncated---
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ b00fa38a9c1cba044a32a601b49a55a18ed719d1 and < 47cf3387de902e8f61f705b06cb2fc1315d26932≥ b00fa38a9c1cba044a32a601b49a55a18ed719d1 and < 300415caa373a07782fcbc2f8d9429bc2dc27a47≥ b00fa38a9c1cba044a32a601b49a55a18ed719d1 and < a96a44aba556c42b432929d37d60158aca21ad4cversion 5.18 | Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.22%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Deferred
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
3 on the record
Elsewhere on this site
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Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2023-53857 is "bpf: bpf_sk_storage: Fix invalid wait context lockdep report", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.22% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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