{"id":"AZL-55238","summary":"CVE-2024-56593 affecting package kernel for versions less than 5.15.176.3-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: brcmfmac: Fix oops due to NULL pointer dereference in brcmf_sdiod_sglist_rw()\n\nThis patch fixes a NULL pointer dereference bug in brcmfmac that occurs\nwhen a high 'sd_sgentry_align' value applies (e.g. 512) and a lot of queued SKBs\nare sent from the pkt queue.\n\nThe problem is the number of entries in the pre-allocated sgtable, it is\nnents = max(rxglom_size, txglom_size) + max(rxglom_size, txglom_size) \u003e\u003e 4 + 1.\nGiven the default [rt]xglom_size=32 it's actually 35 which is too small.\nWorst case, the pkt queue can end up with 64 SKBs. This occurs when a new SKB\nis added for each original SKB if tailroom isn't enough to hold tail_pad.\nAt least one sg entry is needed for each SKB. So, eventually the \"skb_queue_walk loop\"\nin brcmf_sdiod_sglist_rw may run out of sg entries. This makes sg_next return\nNULL and this causes the oops.\n\nThe patch sets nents to max(rxglom_size, txglom_size) * 2 to be able handle\nthe worst-case.\nBtw. this requires only 64-35=29 * 16 (or 20 if CONFIG_NEED_SG_DMA_LENGTH) = 464\nadditional bytes of memory.","modified":"2026-04-01T05:18:33.118465Z","published":"2024-12-27T15:15:18Z","upstream":["CVE-2024-56593"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-56593"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.176.3-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-55238.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}