Oracle Linux: CVE-2024-56593: ELSA-2025-20095: Unbreakable Enterprise kernel security update (IMPORTANT) (Multiple Advisories)

Oracle Linux: CVE-2024-56593: ELSA-2025-20095: Unbreakable Enterprise kernel security update (IMPORTANT) (Multiple Advisories)

Severity

5

CVSS

(AV:L/AC:L/Au:S/C:N/I:N/A:C)

Published

12/27/2024

Created

02/13/2025

Added

02/11/2025

Modified

02/13/2025

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.

Solution(s)

• oracle-linux-upgrade-kernel-uek

References

• https://attackerkb.com/topics/cve-2024-56593
• CVE - 2024-56593
• ELSA-2025-20095
• ELSA-2025-20100