CVE-2026-64425

Summary

In the Linux kernel, the following vulnerability has been resolved:

io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item

commit 10dc95939817 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work run loop") fixed the obvious case where io_worker_handle_work() took one exit-bit snapshot before draining pending work, but the fix stops one level too early.

io_worker_handle_work() now re-checks IO_WQ_BIT_EXIT in its outer work run loop, yet it still snapshots that bit once before processing a whole dependent linked-work chain. If io_wq_exit_start() sets IO_WQ_BIT_EXIT after the first linked item has started, the remaining linked items can still reuse stale do_kill = false, skip IO_WQ_WORK_CANCEL, and continue running after exit has begun.

Move the check further inside, so it covers linked items too. Note: this is a syzbot special as it loves setting up tons of slow linked work on weird devices like msr that take forever to read, and immediately close the ring. Exit then takes a long time.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux065dd936195a3466b8ebe5f9287400987ee3c063 < 14b7ecad2ec56699325180a744f4b19f046401bbaffected
LinuxLinux27e47500fac23d15b7dc93ff650bc4844d2581bd < d179533c610e1b4c6aa436e3c1fd1b719d2c727caffected
LinuxLinuxd05d99573f81a091547b1778b9a50120f5d6c68a < 6e2f51f3e06773c2ee98ad09738f0908b48f76f9affected
LinuxLinux85eb83694a91c89d9abe615d717c0053c3efa714 < ea61b04e1d7242cb37f5ed2cc91cf21a493f6597affected
LinuxLinux2e8ca1078b14142db2ce51cbd18ff9971560046b < b6f179a653a934736c88d820fe0098c3c2532549affected
LinuxLinuxbdf0bf73006ea8af9327cdb85cfdff4c23a5f966 < 1636d85dc139b07c0449308f2bb5e0c7a2e0da99affected
LinuxLinux10dc959398175736e495f71c771f8641e1ca1907 < ab85765cbe3258b43dc6729af0e6ce3a87a133d8affected
LinuxLinux10dc959398175736e495f71c771f8641e1ca1907 < 29bef9934b2521f787bb15dd1985d4c0d12ae02aaffected
LinuxLinux5.10.253 < 5.10.261affected
LinuxLinux5.15.203 < 5.15.212affected
LinuxLinux6.1.167 < 6.1.178affected
LinuxLinux6.6.122 < 6.6.145affected
LinuxLinux6.12.68 < 6.12.96affected
LinuxLinux6.18.8 < 6.18.39affected
LinuxLinux6.19affected
LinuxLinux0 < 6.19unaffected
LinuxLinux5.10.261 <= 5.10.*unaffected
LinuxLinux5.15.212 <= 5.15.*unaffected
LinuxLinux6.1.178 <= 6.1.*unaffected
LinuxLinux6.6.145 <= 6.6.*unaffected
LinuxLinux6.12.96 <= 6.12.*unaffected
LinuxLinux6.18.39 <= 6.18.*unaffected
LinuxLinux7.1.4 <= 7.1.*unaffected
LinuxLinux7.2-rc1 <= *unaffected

Weaknesses

References