CVE-2026-97619
Received
Received - Intake
Linux kernel io_uring Write Accounting Race Condition
Vulnerability report for CVE-2026-97619, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-25
Last updated on: 2026-09-25
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
io_uring/rw: end write accounting from ->ki_complete
Commit b000145e9907 moved both the fsnotify calls and the write
accounting out of the kiocb completion handler and into the
io_req_rw_complete() task_work. However, only the fsnotify part actually
needed to move as it may sleep. Ending the write accounting is just a
percpu_up_read() on the superblock writers sem.
Deferring it is a problem, because it makes dropping SB_FREEZE_WRITE
protection depend on the ring owner getting to running task_work. But
the task may be blocked in freeze_super(), causing it to never get to
that:
task io-wq worker
--------------------------------------------------------------
io_write()
io_kiocb_start_write() (takes sb_writers, hidden from
lockdep by __sb_writers_release)
write_iter() -> -EIOCBQUEUED
ioctl(FS_IOC_SHUTDOWN)
bdev_freeze()
freeze_super()
percpu_down_write() <- waits for the reader above
io_write()
kiocb_start_write()
percpu_down_read() <- queued
behind the
writer
<bio completes>
io_complete_rw()
queues io_req_rw_complete() <- never runs, task is in D state
End the write from io_complete_rw() instead, and leave only the fsnotify
calls in task_work.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
