CVE-2026-52933 is a vulnerability in Linux Kernel
Published on June 24, 2026
io_uring/poll: fix signed comparison in io_poll_get_ownership()
In the Linux kernel, the following vulnerability has been resolved:
io_uring/poll: fix signed comparison in io_poll_get_ownership()
io_poll_get_ownership() uses a signed comparison to check whether
poll_refs has reached the threshold for the slowpath:
if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS))
atomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG
(BIT(31)) is set in poll_refs, the value becomes negative in
signed arithmetic, so the >= 128 comparison always evaluates to
false and the slowpath is never taken.
Fix this by casting the atomic_read() result to unsigned int
before the comparison, so that the cancel flag is treated as a
large positive value and correctly triggers the slowpath.
Products Associated with CVE-2026-52933
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Affected Versions
Linux:- Version a26a35e9019fd70bf3cf647dcfdae87abc7bacea and below 81bf96b0abbfa4cd47ea32e12596aed3855fb2f3 is affected.
- Version a26a35e9019fd70bf3cf647dcfdae87abc7bacea and below cf522703d4f194991615763697ae25a3f9539763 is affected.
- Version a26a35e9019fd70bf3cf647dcfdae87abc7bacea and below fc47043f3d9af3efa407665b47f8378ec691ba18 is affected.
- Version a26a35e9019fd70bf3cf647dcfdae87abc7bacea and below ea0697129807d718037f618221037aa0660ee3c5 is affected.
- Version a26a35e9019fd70bf3cf647dcfdae87abc7bacea and below c6d191164dc81838d8dbf452a6000f68c558d1ae is affected.
- Version a26a35e9019fd70bf3cf647dcfdae87abc7bacea and below 326941b22806cbf2df1fbfe902b7908b368cce42 is affected.
- Version 4b702b7d11ce1b9d26fc6d7c5a7ef4ac1d455048 is affected.
- Version bc4e6ee16778149811333a969a7a893d4cc110c5 is affected.
- Version 5.15.82 and below 5.16 is affected.
- Version 6.0.11 and below 6.1 is affected.
- Version 6.1 is affected.
- Before 6.1 is unaffected.
- Version 6.1.175, <= 6.1.* is unaffected.
- Version 6.6.140, <= 6.6.* is unaffected.
- Version 6.12.86, <= 6.12.* is unaffected.
- Version 6.18.27, <= 6.18.* is unaffected.
- Version 7.0.4, <= 7.0.* is unaffected.
- Version 7.1, <= * is unaffected.