{"id":"CVE-2026-80825","state":"PUBLISHED","title":"wifi: mt76: mt7925: ensure tx headroom in usb_sdio_tx_prepare_skb","description":"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 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.","publishedAt":"2026-09-04T15:54:29.224Z","updatedAt":"2026-10-19T08:44:17.799Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c948b5da6bbec742b433138e3e3f9537a85af2e5","status":"affected","lessThan":"9a72b180f0575e41471e088e09bddc4b73d6dee2","versionType":"git"},{"version":"c948b5da6bbec742b433138e3e3f9537a85af2e5","status":"affected","lessThan":"22edb6786127271aeba7abd30f152977c605c6a3","versionType":"git"},{"version":"c948b5da6bbec742b433138e3e3f9537a85af2e5","status":"affected","lessThan":"8d481f93588932a95f657671d4e1601b90d130cc","versionType":"git"},{"version":"c948b5da6bbec742b433138e3e3f9537a85af2e5","status":"affected","lessThan":"e5e8fc11a7ac578f16079f855b7fffc1649d053c","versionType":"git"},{"version":"c948b5da6bbec742b433138e3e3f9537a85af2e5","status":"affected","lessThan":"ef3e34874d2332d0f63e72c2c35ce5c93568c125","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/mediatek/mt76/mt7925/mac.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.7","versionType":"semver"},{"version":"6.12.108","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.49","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.13","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2.3","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/mediatek/mt76/mt7925/mac.c"]}],"references":["https://git.kernel.org/stable/c/9a72b180f0575e41471e088e09bddc4b73d6dee2","https://git.kernel.org/stable/c/22edb6786127271aeba7abd30f152977c605c6a3","https://git.kernel.org/stable/c/8d481f93588932a95f657671d4e1601b90d130cc","https://git.kernel.org/stable/c/e5e8fc11a7ac578f16079f855b7fffc1649d053c","https://git.kernel.org/stable/c/ef3e34874d2332d0f63e72c2c35ce5c93568c125"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/80xxx/CVE-2026-80825.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80825","state":"PUBLISHED","datePublished":"2026-09-04T15:54:29.224Z","dateUpdated":"2026-10-19T08:44:17.799Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-26T14:34:25.795Z"},"containers":{"cna":{"title":"wifi: mt76: mt7925: ensure tx headroom in usb_sdio_tx_prepare_skb","descriptions":[{"lang":"en","value":"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 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c948b5da6bbec742b433138e3e3f9537a85af2e5","status":"affected","lessThan":"9a72b180f0575e41471e088e09bddc4b73d6dee2","versionType":"git"},{"version":"c948b5da6bbec742b433138e3e3f9537a85af2e5","status":"affected","lessThan":"22edb6786127271aeba7abd30f152977c605c6a3","versionType":"git"},{"version":"c948b5da6bbec742b433138e3e3f9537a85af2e5","status":"affected","lessThan":"8d481f93588932a95f657671d4e1601b90d130cc","versionType":"git"},{"version":"c948b5da6bbec742b433138e3e3f9537a85af2e5","status":"affected","lessThan":"e5e8fc11a7ac578f16079f855b7fffc1649d053c","versionType":"git"},{"version":"c948b5da6bbec742b433138e3e3f9537a85af2e5","status":"affected","lessThan":"ef3e34874d2332d0f63e72c2c35ce5c93568c125","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/mediatek/mt76/mt7925/mac.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.7","versionType":"semver"},{"version":"6.12.108","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.49","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.13","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2.3","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/mediatek/mt76/mt7925/mac.c"]}],"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"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:44:17.799Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.12.108"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.18.49"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"7.1.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"7.2.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}