CVE-2022-49328: mt76: fix use-after-free by removing a non-RCU wcid pointer
In the Linux kernel, the following vulnerability has been resolved:
mt76: fix use-after-free by removing a non-RCU wcid pointer
Fixes an issue caught by KASAN about use-after-free in mt76txqschedule by protecting mtxq->wcid with rculock between mt76txqschedule and stainfo[alloc, free].
[18853.876689] ================================================================== [18853.876751] BUG: KASAN: use-after-free in mt76txqschedule+0x204/0xaf8 [mt76] [18853.876773] Read of size 8 at addr ffffffaf989a2138 by task mt76-tx phy0/883 [18853.876786] [18853.876810] CPU: 5 PID: 883 Comm: mt76-tx phy0 Not tainted 5.10.100-fix-510-56778d365941-kasan #5 0b01fbbcf41a530f52043508fec2e31a4215
[18853.876840] Call trace: [18853.876861] dumpbacktrace+0x0/0x3ec [18853.876878] showstack+0x20/0x2c [18853.876899] dumpstack+0x11c/0x1ac [18853.876918] printaddressdescription+0x74/0x514 [18853.876934] kasanreport+0x134/0x174 [18853.876948] asanreportload8noabort+0x44/0x50 [18853.876976] mt76txqschedule+0x204/0xaf8 [mt76 074e03e4640e97fe7405ee1fab547b81c4fa45d2] [18853.877002] mt76txqscheduleall+0x2c/0x48 [mt76 074e03e4640e97fe7405ee1fab547b81c4fa45d2] [18853.877030] mt7921txworker+0xa0/0x1cc [mt7921common f0875ebac9d7b4754e1010549e7db50fbd90a047] [18853.877054] mt76workerfn+0x190/0x22c [mt76 074e03e4640e97fe7405ee1fab547b81c4fa45d2] [18853.877071] kthread+0x2f8/0x3b8 [18853.877087] retfromfork+0x10/0x30 [18853.877098] [18853.877112] Allocated by task 941: [18853.877131] kasansavestack+0x38/0x68 [18853.877147] kasankmalloc+0xd4/0xfc [18853.877163] kasankmalloc+0x10/0x1c [18853.877177] kmalloc+0x264/0x3c4 [18853.877294] stainfoalloc+0x460/0xf88 [mac80211] [18853.877410] ieee80211prepconnection+0x204/0x1ee0 [mac80211] [18853.877523] ieee80211mgdauth+0x6c4/0xa4c [mac80211] [18853.877635] ieee80211auth+0x20/0x2c [mac80211] [18853.877733] rdevauth+0x7c/0x438 [cfg80211] [18853.877826] cfg80211mlmeauth+0x26c/0x390 [cfg80211] [18853.877919] nl80211authenticate+0x6d4/0x904 [cfg80211] [18853.877938] genlrcvmsg+0x748/0x93c [18853.877954] netlinkrcvskb+0x160/0x2a8 [18853.877969] genlrcv+0x3c/0x54 [18853.877985] netlinkunicastkernel+0x104/0x1ec [18853.877999] netlinkunicast+0x178/0x268 [18853.878015] netlinksendmsg+0x3cc/0x5f0 [18853.878030] socksendmsg+0xb4/0xd8 [18853.878043] syssendmsg+0x2f8/0x53c [18853.878058] syssendmsg+0xe8/0x150 [18853.878071] syssendmsg+0xc4/0x1f4 [18853.878087] arm64compatsyssendmsg+0x88/0x9c [18853.878101] el0svccommon+0x1b4/0x390 [18853.878115] doel0svccompat+0x8c/0xdc [18853.878131] el0svccompat+0x10/0x1c [18853.878146] el0synccompathandler+0xa8/0xcc [18853.878161] el0synccompat+0x188/0x1c0 [18853.878171] [18853.878183] Freed by task 10927: [18853.878200] kasansavestack+0x38/0x68 [18853.878215] kasansettrack+0x28/0x3c [18853.878228] kasansetfreeinfo+0x24/0x48 [18853.878244] kasanslabfree+0x11c/0x154 [18853.878259] kasanslabfree+0x14/0x24 [18853.878273] slabfreefreelisthook+0xac/0x1b0 [18853.878287] kfree+0x104/0x390 [18853.878402] stainfofree+0x198/0x210 [mac80211] [18853.878515] stainfodestroypart2+0x230/0x2d4 [mac80211] [18853.878628] stainfoflush+0x300/0x37c [mac80211] [18853.878740] ieee80211setdisassoc+0x2cc/0xa7c [mac80211] [18853.878851] ieee80211mgddeauth+0x4a4/0x10a0 [mac80211] [18853.878962] ieee80211deauth+0x20/0x2c [mac80211] [18853.879057] rdevdeauth+0x7c/0x438 [cfg80211] [18853.879150] cfg80211mlmedeauth+0x274/0x414 [cfg80211] [18853.879243] cfg80211mlmedown+0xe4/0x118 [cfg80211] [18853.879335] cfg80211disconnect+0x218/0x2d8 [cfg80211] [18853.879427] cfg80211leave+0x17c/0x240 [cfg80211] [18853.879519] cfg80211leave+0x3c/0x58 [cfg80211] [18853.879611] wiphysuspend+0xdc/0x200 [cfg80211] [18853.879628] dpmruncallback+0x58/0x408 [18853.879642] devicesuspend+0x4cc/0x864 [18853.879658] asyncsuspend+0x34/0xf4 [18 ---truncated---
Other sources
In the Linux kernel, the following vulnerability has been resolved:
mt76: fix use-after-free by removing a non-RCU wcid pointer
Fixes an issue caught by KASAN about use-after-free in mt76txqschedule by protecting mtxq->wcid with rculock between mt76txqschedule and stainfo[alloc, free].
[18853.876689] ================================================================== [18853.876751] BUG: KASAN: use-after-free in mt76txqschedule+0x204/0xaf8 [mt76] [18853.876773] Read of size 8 at addr ffffffaf989a2138 by task mt76-tx phy0/883 [18853.876786] [18853.876810] CPU: 5 PID: 883 Comm: mt76-tx phy0 Not tainted 5.10.100-fix-510-56778d365941-kasan #5 0b01fbbcf41a530f52043508fec2e31a4215
[18853.876840] Call trace: [18853.876861] dumpbacktrace+0x0/0x3ec [18853.876878] showstack+0x20/0x2c [18853.876899] dumpstack+0x11c/0x1ac [18853.876918] printaddressdescription+0x74/0x514 [18853.876934] kasanreport+0x134/0x174 [18853.876948] asanreportload8noabort+0x44/0x50 [18853.876976] mt76txqschedule+0x204/0xaf8 [mt76 074e03e4640e97fe7405ee1fab547b81c4fa45d2] [18853.877002] mt76txqscheduleall+0x2c/0x48 [mt76 074e03e4640e97fe7405ee1fab547b81c4fa45d2] [18853.877030] mt7921txworker+0xa0/0x1cc [mt7921common f0875ebac9d7b4754e1010549e7db50fbd90a047] [18853.877054] mt76workerfn+0x190/0x22c [mt76 074e03e4640e97fe7405ee1fab547b81c4fa45d2] [18853.877071] kthread+0x2f8/0x3b8 [18853.877087] retfromfork+0x10/0x30 [18853.877098] [18853.877112] Allocated by task 941: [18853.877131] kasansavestack+0x38/0x68 [18853.877147] kasankmalloc+0xd4/0xfc [18853.877163] kasankmalloc+0x10/0x1c [18853.877177] kmalloc+0x264/0x3c4 [18853.877294] stainfoalloc+0x460/0xf88 [mac80211] [18853.877410] ieee80211prepconnection+0x204/0x1ee0 [mac80211] [18853.877523] ieee80211mgdauth+0x6c4/0xa4c [mac80211] [18853.877635] ieee80211auth+0x20/0x2c [mac80211] [18853.877733] rdevauth+0x7c/0x438 [cfg80211] [18853.877826] cfg80211mlmeauth+0x26c/0x390 [cfg80211] [18853.877919] nl80211authenticate+0x6d4/0x904 [cfg80211] [18853.877938] genlrcvmsg+0x748/0x93c [18853.877954] netlinkrcvskb+0x160/0x2a8 [18853.877969] genlrcv+0x3c/0x54 [18853.877985] netlinkunicastkernel+0x104/0x1ec [18853.877999] netlinkunicast+0x178/0x268 [18853.878015] netlinksendmsg+0x3cc/0x5f0 [18853.878030] socksendmsg+0xb4/0xd8 [18853.878043] syssendmsg+0x2f8/0x53c [18853.878058] syssendmsg+0xe8/0x150 [18853.878071] syssendmsg+0xc4/0x1f4 [18853.878087] arm64compatsyssendmsg+0x88/0x9c [18853.878101] el0svccommon+0x1b4/0x390 [18853.878115] doel0svccompat+0x8c/0xdc [18853.878131] el0svccompat+0x10/0x1c [18853.878146] el0synccompathandler+0xa8/0xcc [18853.878161] el0synccompat+0x188/0x1c0 [18853.878171] [18853.878183] Freed by task 10927: [18853.878200] kasansavestack+0x38/0x68 [18853.878215] kasansettrack+0x28/0x3c [18853.878228] kasansetfreeinfo+0x24/0x48 [18853.878244] kasanslabfree+0x11c/0x154 [18853.878259] kasanslabfree+0x14/0x24 [18853.878273] slabfreefreelisthook+0xac/0x1b0 [18853.878287] kfree+0x104/0x390 [18853.878402] stainfofree+0x198/0x210 [mac80211] [18853.878515] stainfodestroypart2+0x230/0x2d4 [mac80211] [18853.878628] stainfoflush+0x300/0x37c [mac80211] [18853.878740] ieee80211setdisassoc+0x2cc/0xa7c [mac80211] [18853.878851] ieee80211mgddeauth+0x4a4/0x10a0 [mac80211] [18853.878962] ieee80211deauth+0x20/0x2c [mac80211] [18853.879057] rdevdeauth+0x7c/0x438 [cfg80211] [18853.879150] cfg80211mlmedeauth+0x274/0x414 [cfg80211] [18853.879243] cfg80211mlmedown+0xe4/0x118 [cfg80211] [18853.879335] cfg80211disconnect+0x218/0x2d8 [cfg80211] [18853.879427] cfg80211leave+0x17c/0x240 [cfg80211] [18853.879519] cfg80211leave+0x3c/0x58 [cfg80211] [18853.879611] wiphysuspend+0xdc/0x200 [cfg80211] [18853.879628] dpmruncallback+0x58/0x408 [18853.879642] devicesuspend+0x4cc/0x864 [18853.879658] asyncsuspend+0x34/0xf4 [18 ---truncated---
— NVD
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Linux kernel mt76to a version that resolves this vulnerability.Fixed in 5.10.100-fix-510-56778d365941-kasan - Configuration
Fix the mt76 use-after-free by protecting mtxq->wcid with rcu_lock between mt76_txq_schedule and mt76_txq_schedule_all, i.e., remove/avoid the non-RCU wcid pointer so that sta_info_{alloc,free} is handled safely.
mt76_txq_schedule (mt76 driver) mtxq->wcid pointer protection = use RCU lock (rcu_lock) / remove non-RCU wcid pointer
Event History
Frequently Asked Questions
What is the severity of CVE-2022-49328?
CVE-2022-49328 has been classified as a medium severity vulnerability due to the potential for use-after-free errors in the Linux kernel.
How do I fix CVE-2022-49328?
To fix CVE-2022-49328, update your Linux kernel to a version that includes the patches addressing the vulnerability.
Which versions of the Linux kernel are affected by CVE-2022-49328?
CVE-2022-49328 affects Linux kernel versions prior to 5.15.58 and versions between 5.16 and 5.17.14.
What type of vulnerability is CVE-2022-49328?
CVE-2022-49328 is a use-after-free vulnerability that can lead to memory corruption in the Linux kernel.
Is there an exploit available for CVE-2022-49328?
As of now, there are no public exploits documented for CVE-2022-49328, but it is advisable to patch the vulnerability immediately.