CVE-2024-56593

MEDIUM EPSS 13.0%
Published Dec 27, 20241y ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Dec 27, 2024 1y ago
Last Modified Jun 17, 2026 1w ago

Description

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.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
13.0% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-476 NULL Pointer Dereference Memory Safety

Affected Products 6

VendorProductVersionRange
linuxlinux_kernel* <5.4.287
linuxlinux_kernel*≥5.5  –  <5.10.231
linuxlinux_kernel*≥5.11  –  <5.15.174
linuxlinux_kernel*≥5.16  –  <6.1.120
linuxlinux_kernel*≥6.2  –  <6.6.66
linuxlinux_kernel*≥6.7  –  <6.12.5

References 9

  • git.kernel.org https://git.kernel.org/stable/c/07c020c6d14d29e5a3ea4e4576b8ecf956a80834
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/342f87d263462c2670b77ea9a32074cab2ac6fa1
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/34941321b516bd7c6103bd01287d71a1804d19d3
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/67a25ea28f8ec1da8894f2f115d01d3becf67dc7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7522d7d745d13fbeff3350fe6aa56c8dae263571
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/857282b819cbaa0675aaab1e7542e2c0579f52d7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/dfb3f9d3f602602de208da7bdcc0f6d5ee74af68
    Patch
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/07c020c6d14d29e5a3ea4e4576b8ecf956a80834
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/342f87d263462c2670b77ea9a32074cab2ac6fa1
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/34941321b516bd7c6103bd01287d71a1804d19d3
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/67a25ea28f8ec1da8894f2f115d01d3becf67dc7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7522d7d745d13fbeff3350fe6aa56c8dae263571
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/857282b819cbaa0675aaab1e7542e2c0579f52d7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/dfb3f9d3f602602de208da7bdcc0f6d5ee74af68
    Patch