CVE-2024-56593

wifi: brcmfmac: Fix oops due to NULL pointer dereference in brcmf_sdiod_sglist_rw()

MEDIUM

5.5

CVSS Score

Published: December 27, 2024 at 02:51 PM UTC

Updated: June 17, 2026 at 08:12 AM UTC

1 product affected across 1 vendorLinux Kernel

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Severity

MEDIUM5.5

Exploit prediction

EPSS 0.2%

SSVC

No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

v < 5.4.2873.15 ≤ v < 5.10.2313.15 ≤ v < 5.15.1743.15 ≤ v < 5.4.2873.15 ≤ v < 6.1.1203.15 ≤ v < 6.12.53.15 ≤ v < 6.133.15 ≤ v < 6.6.665.11 ≤ v < 5.15.1745.16 ≤ v < 6.1.1205.5 ≤ v < 5.10.2316.2 ≤ v < 6.6.666.7 ≤ v < 6.12.53.15af1fa210f4fc6e304b859b386a3c8a266b1110ab

Vendor states this is fixed in 07c020c6d14d29e5a3ea4e4576b8ecf956a80834 (fixed)

Vendor states this is fixed in 342f87d263462c2670b77ea9a32074cab2ac6fa1 (fixed)

Vendor states this is fixed in 34941321b516bd7c6103bd01287d71a1804d19d3 (fixed)

Vendor states this is fixed in 67a25ea28f8ec1da8894f2f115d01d3becf67dc7 (fixed)

Vendor states this is fixed in 7522d7d745d13fbeff3350fe6aa56c8dae263571 (fixed)

Vendor states this is fixed in 857282b819cbaa0675aaab1e7542e2c0579f52d7 (fixed)

Vendor states this is fixed in dfb3f9d3f602602de208da7bdcc0f6d5ee74af68 (fixed)

Vendor states this is fixed in 3.15 (unaffected)

Vendor states this is fixed in 5.10.231 (unaffected)

Vendor states this is fixed in 5.15.174 (unaffected)

Vendor states this is fixed in 5.4.287 (unaffected)

Vendor states this is fixed in 6.1.120 (unaffected)