CVE-2025-21744
Description
In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: fix NULL pointer dereference in brcmf_txfinalize() On removal of the device or unloading of the kernel module a potential NULL pointer dereference occurs. The following sequence deletes the interface: brcmf_detach() brcmf_remove_interface() brcmf_del_if() Inside the brcmf_del_if() function the drvr->if2bss[ifidx] is updated to BRCMF_BSSIDX_INVALID (-1) if the bsscfgidx matches. After brcmf_remove_interface() call the brcmf_proto_detach() function is called providing the following sequence: brcmf_detach() brcmf_proto_detach() brcmf_proto_msgbuf_detach() brcmf_flowring_detach() brcmf_msgbuf_delete_flowring() brcmf_msgbuf_remove_flowring() brcmf_flowring_delete() brcmf_get_ifp() brcmf_txfinalize() Since brcmf_get_ip() can and actually will return NULL in this case the call to brcmf_txfinalize() will result in a NULL pointer dereference inside brcmf_txfinalize() when trying to update ifp->ndev->stats.tx_errors. This will only happen if a flowring still has an skb. Although the NULL pointer dereference has only been seen when trying to update the tx statistic, all other uses of the ifp pointer have been guarded as well with an early return if ifp is NULL.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or โ if you've already worked around this in production โ publish your fix to the community-verified tier.
โ Propose a mitigation on Community โ Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 6.1.129-1 |
| debian | bullseye | fixed | 5.10.237-1 |
| debian | forky | fixed | 6.12.15-1 |
| debian | sid | fixed | 6.12.15-1 |
| debian | trixie | fixed | 6.12.15-1 |
| linux-kernel | affected | 6.1.129 |
References
- https://git.kernel.org/stable/c/2326e19190e176fd72bb542b837a9d2b7fcb8693
- https://git.kernel.org/stable/c/3877fc67bd3d5566cc12763bce39710ceb74a97d
- https://git.kernel.org/stable/c/4e51d6d093e763348916e69d06d87e0a5593661b
- https://git.kernel.org/stable/c/59ff4fa653ff6db07c61152516ffba79c2a74bda
- https://git.kernel.org/stable/c/61541d9b5a23df33934fcc620a3a81f246b1b240
- https://git.kernel.org/stable/c/68abd0c4ebf24cd499841a488b97a6873d5efabb
- https://git.kernel.org/stable/c/a2beefc4fa49ebc22e664dc6b39dbd054f8488f9
- https://git.kernel.org/stable/c/fbbfef2a5b858eab55741a58b2ac9a0cc8d53c58
- https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html
- https://www.suse.com/security/cve/CVE-2025-21744.html
- https://security-tracker.debian.org/tracker/CVE-2025-21744
CWEs
CWE-476
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.