{"id":"CVE-2026-74488","title":"wifi: mwifiex: use the subframe length when parsing A-MSDU TDLS frames","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mwifiex: use the subframe length when parsing A-MSDU TDLS frames\n\nmwifiex_11n_dispatch_amsdu_pkt() splits an A-MSDU with\nieee80211_amsdu_to_8023s() and walks the …","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < 707664027bb9307f7268eda403af7c4ccd9b8644","Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < 3b02275833a0d3e6583627995d614fa99bdf364f","Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < a1f0f7dc7eb15754e6931b433edb7beb754c996a","Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < 25e5a3fe4f15e30f74eca42cbf3bcc3a3fbeda79","Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < ece2ebb34247d573142617dfc534a9dc11ba59be","Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < c9dcfe6b8b71369e1d732e2ff622c3696a2f032c","Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < 5a21ab03829cb6d2682c127f22e2b9cd63b4393f","Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < 99a948382af8a225e2d5e54a7052158cd6281cc6","Linux 4.5"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T18:57:58.234804Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T19:05:49.470Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74488","references":[{"url":"https://git.kernel.org/stable/c/707664027bb9307f7268eda403af7c4ccd9b8644"},{"url":"https://git.kernel.org/stable/c/3b02275833a0d3e6583627995d614fa99bdf364f"},{"url":"https://git.kernel.org/stable/c/a1f0f7dc7eb15754e6931b433edb7beb754c996a"},{"url":"https://git.kernel.org/stable/c/25e5a3fe4f15e30f74eca42cbf3bcc3a3fbeda79"},{"url":"https://git.kernel.org/stable/c/ece2ebb34247d573142617dfc534a9dc11ba59be"},{"url":"https://git.kernel.org/stable/c/c9dcfe6b8b71369e1d732e2ff622c3696a2f032c"},{"url":"https://git.kernel.org/stable/c/5a21ab03829cb6d2682c127f22e2b9cd63b4393f"},{"url":"https://git.kernel.org/stable/c/99a948382af8a225e2d5e54a7052158cd6281cc6"}],"tags":["cve.org"],"epss":0.00255,"epssPercentile":0.15953,"ingestedAt":"2026-10-16T19:46:24.358Z","slug":"CVE-2026-74488","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mwifiex: use the subframe length when parsing A-MSDU TDLS frames\n\nmwifiex_11n_dispatch_amsdu_pkt() splits an A-MSDU with\nieee80211_amsdu_to_8023s() and walks the resulting subframes. For each\nsubframe it passes the subframe data pointer to\nmwifiex_process_tdls_action_frame(), but pairs it with skb->len, the\nlength of the A-MSDU parent, instead of rx_skb->len:\n\n\trx_skb = __skb_dequeue(&list);\n\trx_hdr = (struct rx_packet_hdr *)rx_skb->data;\n\tif (ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&\n\t    ntohs(rx_hdr->eth803_hdr.h_proto) == ETH_P_TDLS) {\n\t\tmwifiex_process_tdls_action_frame(priv, (u8 *)rx_hdr,\n\t\t\t\t\t\t  skb->len);\n\t}\n\nThe parent is not a valid description of that buffer, and may not be\nvalid memory at all. ieee80211_amsdu_to_8023s() ends with\n\n\tif (!reuse_skb)\n\t\tdev_kfree_skb(skb);\n\nand it only sets reuse_skb when the parent is linear, is not a\nhead_frag, and is being consumed as the *last* subframe. So when the\nparent does not qualify for reuse it has already been freed, and the\nread of skb->len is a use-after-free. When it is reused, skb->len is\nthe length of the last subframe, applied to every earlier subframe,\nwhich over-states the buffer whenever an earlier subframe is shorter.\n\nThe callee cannot absorb a wrong length, because it derives its own\nceiling from the value it is given. Each frame type computes\n\n\ties_len = len - sizeof(struct ethhdr) - TDLS_*_FIX_LEN;\n\nand the element walk is then bounded entirely against that ceiling,\n\n\tfor (end = pos + ies_len; pos + 1 < end; pos += 2 + pos[1]) {\n\t\tu8 ie_len = pos[1];\n\n\t\tif (pos + 2 + ie_len > end)\n\t\t\tbreak;\n\nso a too-large len moves end past the end of the subframe and the walk\nreads and copies beyond it. The A-MSDU layout is chosen by the sender,\nwhich makes the difference between the last subframe and a shorter\nearlier one remotely selectable. Reaching this requires TDLS support in\nfirmware and the TDLS ethertype on the subframe.\n\nThe other caller, mwifiex_process_rx_packet(), is correct: it passes a\npointer and a length that describe the same region of the RX buffer.\n\nPass rx_skb->len, the length of the subframe actually being parsed.\n\n## Affected\n\n- `Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < 707664027bb9307f7268eda403af7c4ccd9b8644`\n- `Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < 3b02275833a0d3e6583627995d614fa99bdf364f`\n- `Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < a1f0f7dc7eb15754e6931b433edb7beb754c996a`\n- `Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < 25e5a3fe4f15e30f74eca42cbf3bcc3a3fbeda79`\n- `Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < ece2ebb34247d573142617dfc534a9dc11ba59be`\n- `Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < c9dcfe6b8b71369e1d732e2ff622c3696a2f032c`\n- `Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < 5a21ab03829cb6d2682c127f22e2b9cd63b4393f`\n- `Linux >= 776f742040ca5eb6242c60f29ac73d5752a5b621 < 99a948382af8a225e2d5e54a7052158cd6281cc6`\n- `Linux 4.5`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}