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.
Product status
af1fa210f4fc6e304b859b386a3c8a266b1110ab (git) before 342f87d263462c2670b77ea9a32074cab2ac6fa1
af1fa210f4fc6e304b859b386a3c8a266b1110ab (git) before 7522d7d745d13fbeff3350fe6aa56c8dae263571
af1fa210f4fc6e304b859b386a3c8a266b1110ab (git) before dfb3f9d3f602602de208da7bdcc0f6d5ee74af68
af1fa210f4fc6e304b859b386a3c8a266b1110ab (git) before 67a25ea28f8ec1da8894f2f115d01d3becf67dc7
af1fa210f4fc6e304b859b386a3c8a266b1110ab (git) before 07c020c6d14d29e5a3ea4e4576b8ecf956a80834
af1fa210f4fc6e304b859b386a3c8a266b1110ab (git) before 34941321b516bd7c6103bd01287d71a1804d19d3
af1fa210f4fc6e304b859b386a3c8a266b1110ab (git) before 857282b819cbaa0675aaab1e7542e2c0579f52d7
3.15
Any version before 3.15
5.4.287 (semver)
5.10.231 (semver)
5.15.174 (semver)
6.1.120 (semver)
6.6.66 (semver)
6.12.5 (semver)
6.13 (original_commit_for_fix)
References
lists.debian.org/debian-lts-announce/2025/03/msg00001.html
lists.debian.org/debian-lts-announce/2025/03/msg00002.html
git.kernel.org/...c/342f87d263462c2670b77ea9a32074cab2ac6fa1
git.kernel.org/...c/7522d7d745d13fbeff3350fe6aa56c8dae263571
git.kernel.org/...c/dfb3f9d3f602602de208da7bdcc0f6d5ee74af68
git.kernel.org/...c/67a25ea28f8ec1da8894f2f115d01d3becf67dc7
git.kernel.org/...c/07c020c6d14d29e5a3ea4e4576b8ecf956a80834
git.kernel.org/...c/34941321b516bd7c6103bd01287d71a1804d19d3
git.kernel.org/...c/857282b819cbaa0675aaab1e7542e2c0579f52d7