CVE-2026-53096: Linux kernel · bpf: Use RCU-safe iteration in dev_map_redirect_multi() SKB path
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in d4c4bd231ebad70e6f30db429e9640bf378b2f52 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in d4c4bd231ebad70e6f30db429e9640bf378b2f52, cb2c1f3cf65b855548e1b8d55a08bfbaa5a0901a, b089aa6e94d7a08e74d076a0fe274842dc9feccc +4
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Use RCU-safe iteration in dev_map_redirect_multi() SKB path The DEVMAP_HASH branch in dev_map_redirect_multi() uses hlist_for_each_entry_safe() to iterate hash buckets, but this function runs under RCU protection (called from xdp_do_generic_redirect_map() in softirq context). Concurrent writers (__dev_map_hash_update_elem, dev_map_hash_delete_elem) modify the list using RCU primitives (hlist_add_head_rcu, hlist_del_rcu). hlist_for_each_entry_safe() performs plain pointer dereferences without rcu_dereference(), missing the acquire barrier needed to pair with writers' rcu_assign_pointer(). On weakly-ordered architectures (ARM64, POWER), a reader can observe a partially-constructed node. It also defeats CONFIG_PROVE_RCU lockdep validation and KCSAN data-race detection. Replace with hlist_for_each_entry_rcu() using rcu_read_lock_bh_held() as the lockdep condition, consistent with the rcu_dereference_check() used in the DEVMAP (non-hash) branch of the same functions. Also fix the same incorrect lockdep_is_held(&dtab->index_lock) condition in dev_map_enqueue_multi(), where the lock is not held either.
References
- git.kernel.org/stable/c/4a3d0fe30b907ff324b1b49756f7e713d67f3645 (opens in a new tab)
- git.kernel.org/stable/c/b089aa6e94d7a08e74d076a0fe274842dc9feccc (opens in a new tab)
- git.kernel.org/stable/c/571a05ea1baaccc0dc1e0d227b2cbc978b96d392 (opens in a new tab)
- git.kernel.org/stable/c/cb2c1f3cf65b855548e1b8d55a08bfbaa5a0901a (opens in a new tab)
- git.kernel.org/stable/c/d4c4bd231ebad70e6f30db429e9640bf378b2f52 (opens in a new tab)
- git.kernel.org/stable/c/7027e705062482a8cea43a1c13ede3c35653966f (opens in a new tab)
- git.kernel.org/stable/c/8ed82f807bb09d2c8455aaa665f2c6cb17bc6a19 (opens in a new tab)