{"id":"CVE-2026-80825","title":"wifi: mt76: mt7925: ensure tx headroom in usb_sdio_tx_prepare_skb","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mt76: mt7925: ensure tx headroom in usb_sdio_tx_prepare_skb\n\nmt7925_usb_sdio_tx_prepare_skb() pushes a TX descriptor and a USB\nheader onto every skb and assumes t…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= c948b5da6bbec742b433138e3e3f9537a85af2e5 < 9a72b180f0575e41471e088e09bddc4b73d6dee2","Linux >= c948b5da6bbec742b433138e3e3f9537a85af2e5 < 22edb6786127271aeba7abd30f152977c605c6a3","Linux >= c948b5da6bbec742b433138e3e3f9537a85af2e5 < 8d481f93588932a95f657671d4e1601b90d130cc","Linux >= c948b5da6bbec742b433138e3e3f9537a85af2e5 < e5e8fc11a7ac578f16079f855b7fffc1649d053c","Linux >= c948b5da6bbec742b433138e3e3f9537a85af2e5 < ef3e34874d2332d0f63e72c2c35ce5c93568c125","Linux 6.7"],"published":"2026-09-04","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:44:17.799Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80825","references":[{"url":"https://git.kernel.org/stable/c/9a72b180f0575e41471e088e09bddc4b73d6dee2"},{"url":"https://git.kernel.org/stable/c/22edb6786127271aeba7abd30f152977c605c6a3"},{"url":"https://git.kernel.org/stable/c/8d481f93588932a95f657671d4e1601b90d130cc"},{"url":"https://git.kernel.org/stable/c/e5e8fc11a7ac578f16079f855b7fffc1649d053c"},{"url":"https://git.kernel.org/stable/c/ef3e34874d2332d0f63e72c2c35ce5c93568c125"}],"tags":["cve.org"],"epss":0.00168,"epssPercentile":0.05664,"ingestedAt":"2026-10-19T09:16:01.503Z","slug":"CVE-2026-80825","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mt76: mt7925: ensure tx headroom in usb_sdio_tx_prepare_skb\n\nmt7925_usb_sdio_tx_prepare_skb() pushes a TX descriptor and a USB\nheader onto every skb and assumes the headroom for them is already\nthere. That holds for locally generated traffic, where mac80211\nreserves hw->extra_tx_headroom, but forwarded frames are sent through\nieee80211_8023_xmit(), which does not reserve it. Bridge a wired\ninterface to an mt7925u AP and the first forwarded frame that arrives\nshort panics the kernel:\n\n skbuff: skb_under_panic: len:415 put:4 tail:0x19b end:0x640 dev:wlan1\n kernel BUG at net/core/skbuff.c:212!\n Call trace:\n  skb_panic+0x58/0x60 (P)\n  skb_push+0x58/0x60\n  mt7925_usb_sdio_tx_prepare_skb+0xf8/0x1b8 [mt7925_common]\n  mt76u_tx_queue_skb+0xa0/0x1f8 [mt76_usb]\n  __mt76_tx_queue_skb+0x54/0xe8 [mt76]\n  mt76_txq_schedule.part.0+0x204/0x478 [mt76]\n  mt76_txq_schedule_all+0x50/0x80 [mt76]\n  mt792x_tx_worker+0x68/0x100 [mt792x_lib]\n  __mt76_worker_fn+0x84/0x150 [mt76]\n\nWhether a given setup hits it depends on how much headroom the ingress\nnetdev leaves in its rx skbs. Reproduced on a Raspberry Pi 5 bridging\nonboard ethernet to a Netgear A9000; originally reported on an MT7986\nrouter running OpenWrt. Nick Morrow's testing on a Pi 4 (bcmgenet),\nwhich leaves more headroom, helped narrow the trigger to the ingress\npath.\n\nThe same bug was fixed on mt7921 by commit 98c4d0abf5c4 (\"mt76:\nmt7921: don't assume adequate headroom for SDIO headers\"), but mt7925\nwas copied from mt7921 without the fix. Add the same guard here.\n\n## Affected\n\n- `Linux >= c948b5da6bbec742b433138e3e3f9537a85af2e5 < 9a72b180f0575e41471e088e09bddc4b73d6dee2`\n- `Linux >= c948b5da6bbec742b433138e3e3f9537a85af2e5 < 22edb6786127271aeba7abd30f152977c605c6a3`\n- `Linux >= c948b5da6bbec742b433138e3e3f9537a85af2e5 < 8d481f93588932a95f657671d4e1601b90d130cc`\n- `Linux >= c948b5da6bbec742b433138e3e3f9537a85af2e5 < e5e8fc11a7ac578f16079f855b7fffc1649d053c`\n- `Linux >= c948b5da6bbec742b433138e3e3f9537a85af2e5 < ef3e34874d2332d0f63e72c2c35ce5c93568c125`\n- `Linux 6.7`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}