wifi: mt76: mt7925: ensure tx headroom in usb_sdio_tx_prepare_skb
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.12.108, 6.18.49, 7.1.13, 7.2.3
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7925: ensure tx headroom in usb_sdio_tx_prepare_skb mt7925_usb_sdio_tx_prepare_skb() pushes a TX descriptor and a USB header onto every skb and assumes the headroom for them is already there. That holds for locally generated traffic, where mac80211 reserves hw->extra_tx_headroom, but forwarded frames are sent through ieee80211_8023_xmit(), which does not reserve it. Bridge a wired interface to an mt7925u AP and the first forwarded frame that arrives short panics the kernel: skbuff: skb_under_panic: len:415 put:4 tail:0x19b end:0x640 dev:wlan1 kernel BUG at net/core/skbuff.c:212! Call trace: skb_panic+0x58/0x60 (P) skb_push+0x58/0x60 mt7925_usb_sdio_tx_prepare_skb+0xf8/0x1b8 [mt7925_common] mt76u_tx_queue_skb+0xa0/0x1f8 [mt76_usb] __mt76_tx_queue_skb+0x54/0xe8 [mt76] mt76_txq_schedule.part.0+0x204/0x478 [mt76] mt76_txq_schedule_all+0x50/0x80 [mt76] mt792x_tx_worker+0x68/0x100 [mt792x_lib] __mt76_worker_fn+0x84/0x150 [mt76] Whether a given setup hits it depends on how much headroom the ingress netdev leaves in its rx skbs. Reproduced on a Raspberry Pi 5 bridging onboard ethernet to a Netgear A9000; originally reported on an MT7986 router running OpenWrt. Nick Morrow's testing on a Pi 4 (bcmgenet), which leaves more headroom, helped narrow the trigger to the ingress path. The same bug was fixed on mt7921 by commit 98c4d0abf5c4 ("mt76: mt7921: don't assume adequate headroom for SDIO headers"), but mt7925 was copied from mt7921 without the fix. Add the same guard here.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From c948b5da6bbec742b433138e3e3f9537a85af2e5 · fixed in 9a72b180f0575e41471e088e09bddc4b73d6dee2; From c948b5da6bbec742b433138e3e3f9537a85af2e5 · fixed in 22edb6786127271aeba7abd30f152977c605c6a3; From c948b5da6bbec742b433138e3e3f9537a85af2e5 · fixed in 8d481f93588932a95f657671d4e1601b90d130cc; From c948b5da6bbec742b433138e3e3f9537a85af2e5 · fixed in e5e8fc11a7ac578f16079f855b7fffc1649d053c; From c948b5da6bbec742b433138e3e3f9537a85af2e5 · fixed in ef3e34874d2332d0f63e72c2c35ce5c93568c125
- Linux Linux
6.7
- KernelLinux
From 6.7.0 · fixed in 6.12.108; From 6.13.0 · fixed in 6.18.49; From 6.19.0 · fixed in 7.1.13; From 7.2.0 · fixed in 7.2.3