In the Linux kernel, the following vulnerability has been resolved: io_uring: fix shared sqpoll cancellation hangs [ 736.982891] INFO: task iou-sqp-4294:4295 blocked for more than 122 seconds. [ 736.982897] Call Trace: [ 736.982901] schedule+0x68/0xe0 [ 736.982903] io_uring_cancel_sqpoll+0xdb/0x110 [ 736.982908] io_sqpoll_cancel_cb+0x24/0x30 [ 736.982911] io_run_task_work_head+0x28/0x50 [ 736.982913] io_sq_thread+0x4e3/0x720 We call io_uring_cancel_sqpoll() one by one for each ctx either in sq_thread() itself or via task works, and it\'s intended to cancel all requests of a specified context. However the function uses per-task counters to track the number of inflight requests, so it counts more requests than available via currect io_uring ctx and goes to sleep for them to appear (e.g. from IRQ), that will never happen. Cancel a bit more than before, i.e. all ctxs that share sqpoll and continue to use shared counters. Don\'t forget that we should not remove ctx from the list before running that task_work sqpoll-cancel, otherwise the function wouldn\'t be able to find the context and will hang.
Find out more about CVE-2021-46942 from the MITRE-CVE dictionary and NIST NVD
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Product Name | Status | Defect | Fixed | Downloads |
---|---|---|---|---|
Linux | ||||
Wind River Linux LTS 17 | Requires LTSS | -- | -- | -- |
Wind River Linux 8 | Requires LTSS | -- | -- | -- |
Wind River Linux 9 | Requires LTSS | -- | -- | -- |
Wind River Linux 7 | Requires LTSS | -- | -- | -- |
Wind River Linux LTS 21 | Won't Fix | -- | -- | -- |
Wind River Linux LTS 22 | Not Vulnerable | -- | -- | -- |
Wind River Linux LTS 18 | Requires LTSS | -- | -- | -- |
Wind River Linux LTS 19 | Won't Fix | -- | -- | -- |
Wind River Linux CD release | N/A | -- | -- | -- |
Wind River Linux 6 | Requires LTSS | -- | -- | -- |
Wind River Linux LTS 23 | Not Vulnerable | -- | -- | -- |
VxWorks | ||||
VxWorks 7 | Not Vulnerable | -- | -- | -- |
VxWorks 6.9 | Not Vulnerable | -- | -- | -- |
Helix Virtualization Platform Cert Edition | ||||
Helix Virtualization Platform Cert Edition | Not Vulnerable | -- | -- | -- |
Product Name | Status | Defect | Fixed | Downloads |
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