wifi: brcmfmac: Fix oops due to NULL pointer dereference in brcmf_sdiod_sglist_rw()
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 3 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-476.
Summary
In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: Fix oops due to NULL pointer dereference in brcmf_sdiod_sglist_rw() This patch fixes a NULL pointer dereference bug in brcmfmac that occurs when a high 'sd_sgentry_align' value applies (e.g. 512) and a lot of queued SKBs are sent from the pkt queue. The problem is the number of entries in the pre-allocated sgtable, it is nents = max(rxglom_size, txglom_size) + max(rxglom_size, txglom_size) >> 4 + 1. Given the default [rt]xglom_size=32 it's actually 35 which is too small. Worst case, the pkt queue can end up with 64 SKBs. This occurs when a new SKB is added for each original SKB if tailroom isn't enough to hold tail_pad. At least one sg entry is needed for each SKB. So, eventually the "skb_queue_walk loop" in brcmf_sdiod_sglist_rw may run out of sg entries. This makes sg_next return NULL and this causes the oops. The patch sets nents to max(rxglom_size, txglom_size) * 2 to be able handle the worst-case. Btw. this requires only 64-35=29 * 16 (or 20 if CONFIG_NEED_SG_DMA_LENGTH) = 464 additional bytes of memory.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 3.15 and later | 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.66, 6.12.5, 6.13 | Patch available | CNA |
- Linux VendorLinux Affected 3.15 and later Fixed in 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.66, 6.12.5, 6.13 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 5.4.287; 5.5 to before 5.10.231; 5.11 to before 5.15.174; 5.16 to before 6.1.120; 6.2 to before 6.6.66; 6.7 to before 6.12.5 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 5.4.287; 5.5 to before 5.10.231; 5.11 to before 5.15.174; 5.16 to before 6.1.120; 6.2 to before 6.6.66; 6.7 to before 6.12.5 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.66, 6.12.5, 6.13
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2024-56593
- 2026-10-03 Alias added: GHSA-9pg7-c56m-xqjx
References
Patch 7
- https://git.kernel.org/stable/c/342f87d263462c2670b77ea9a32074cab2ac6fa1
- https://git.kernel.org/stable/c/7522d7d745d13fbeff3350fe6aa56c8dae263571
- https://git.kernel.org/stable/c/dfb3f9d3f602602de208da7bdcc0f6d5ee74af68
- https://git.kernel.org/stable/c/67a25ea28f8ec1da8894f2f115d01d3becf67dc7
- https://git.kernel.org/stable/c/07c020c6d14d29e5a3ea4e4576b8ecf956a80834
- https://git.kernel.org/stable/c/34941321b516bd7c6103bd01287d71a1804d19d3
- https://git.kernel.org/stable/c/857282b819cbaa0675aaab1e7542e2c0579f52d7
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2024-56593 · CVE Program
- CVE-2024-56593 · NVD
- FIRST EPSS
- GHSA-9pg7-c56m-xqjx · GitHub Advisory Database · CC BY 4.0
- CVE-2024-56593 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences