| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-56593: wifi: brcmfmac: Fix oops due to NULL pointer dereference in brcmf_sdiod_sglist_rw() |
| |
| 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. |
| |
| The Linux kernel CVE team has assigned CVE-2024-56593 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.4.287 with commit 342f87d263462c2670b77ea9a32074cab2ac6fa1 |
| Fixed in 5.10.231 with commit 7522d7d745d13fbeff3350fe6aa56c8dae263571 |
| Fixed in 5.15.174 with commit dfb3f9d3f602602de208da7bdcc0f6d5ee74af68 |
| Fixed in 6.1.120 with commit 67a25ea28f8ec1da8894f2f115d01d3becf67dc7 |
| Fixed in 6.6.66 with commit 07c020c6d14d29e5a3ea4e4576b8ecf956a80834 |
| Fixed in 6.12.5 with commit 34941321b516bd7c6103bd01287d71a1804d19d3 |
| Fixed in 6.13 with commit 857282b819cbaa0675aaab1e7542e2c0579f52d7 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-56593 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| 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 |
