CVE-2024-56593: wifi: brcmfmac: Fix oops due to NULL pointer dereference in brcmf_sdiod_sglist_rw()
Vulnerability summary
CVE-2024-56593 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 15.1% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 58 · Related 53Timeline
- 27-12-2024PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
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 metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.24%
Chance of exploitation in the next 30 days
Percentile
15%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.24% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu135 products
- linux< 4.4.0-278.312 | < 4.15.0-247.259 | < 5.4.0-211.231 | < 5.15.0-135.146 | < 6.8.0-58.60
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 4.4.0-1152.158 | < 4.4.0-1190.205 | < 4.15.0-1189.202 | < 5.4.0-1142.152 | < 5.15.0-1080.87 | < 6.8.0-1027.29
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ af1fa210f4fc6e304b859b386a3c8a266b1110ab, < 342f87d263462c2670b77ea9a32074cab2ac6fa1 | ≥ af1fa210f4fc6e304b859b386a3c8a266b1110ab, < 7522d7d745d13fbeff3350fe6aa56c8dae263571 | ≥ af1fa210f4fc6e304b859b386a3c8a266b1110ab, < dfb3f9d3f602602de208da7bdcc0f6d5ee74af68 | ≥ af1fa210f4fc6e304b859b386a3c8a266b1110ab, < 67a25ea28f8ec1da8894f2f115d01d3becf67dc7 | ≥ af1fa210f4fc6e304b859b386a3c8a266b1110ab, < 07c020c6d14d29e5a3ea4e4576b8ecf956a80834 | ≥ af1fa210f4fc6e304b859b386a3c8a266b1110ab, < 34941321b516bd7c6103bd01287d71a1804d19d3 | ≥ af1fa210f4fc6e304b859b386a3c8a266b1110ab, < 857282b819cbaa0675aaab1e7542e2c0579f52d7 | 3.15
- linux_kernel< 5.4.287 | ≥ 5.5, < 5.10.231 | ≥ 5.11, < 5.15.174 | ≥ 5.16, < 6.1.120 | ≥ 6.2, < 6.6.66 | ≥ 6.7, < 6.12.5
Debian1 product
- linux< 6.1.123-1 | < 6.12.5-1
3 vendors · 138 products
