Description
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.
CVSS breakdown
CVSS 3.1
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected products
- Linux / Linuxa26a35e9019fd70bf3cf647dcfdae87abc7bacea – 81bf96b0abbfa4cd47ea32e12596aed3855fb2f3
- Linux / Linuxa26a35e9019fd70bf3cf647dcfdae87abc7bacea – cf522703d4f194991615763697ae25a3f9539763
- Linux / Linuxa26a35e9019fd70bf3cf647dcfdae87abc7bacea – fc47043f3d9af3efa407665b47f8378ec691ba18
- Linux / Linuxa26a35e9019fd70bf3cf647dcfdae87abc7bacea – ea0697129807d718037f618221037aa0660ee3c5
- Linux / Linuxa26a35e9019fd70bf3cf647dcfdae87abc7bacea – c6d191164dc81838d8dbf452a6000f68c558d1ae
- Linux / Linuxa26a35e9019fd70bf3cf647dcfdae87abc7bacea – 326941b22806cbf2df1fbfe902b7908b368cce42
- Linux / Linux4b702b7d11ce1b9d26fc6d7c5a7ef4ac1d455048 – 4b702b7d11ce1b9d26fc6d7c5a7ef4ac1d455048
- Linux / Linuxbc4e6ee16778149811333a969a7a893d4cc110c5 – bc4e6ee16778149811333a969a7a893d4cc110c5
- Linux / Linux5.15.82 – 5.16
- Linux / Linux6.0.11 – 6.1
- Linux / Linux6.1 – 6.1
- Linux / Linux0 – 6.1
- Linux / Linux6.1.175 – 6.1.*
- Linux / Linux6.6.140 – 6.6.*
- Linux / Linux6.12.86 – 6.12.*
- Linux / Linux6.18.27 – 6.18.*
- Linux / Linux7.0.4 – 7.0.*
- Linux / Linux7.1 – *
References
- MISChttps://git.kernel.org/stable/c/81bf96b0abbfa4cd47ea32e12596aed3855fb2f3
- MISChttps://git.kernel.org/stable/c/cf522703d4f194991615763697ae25a3f9539763
- MISChttps://git.kernel.org/stable/c/fc47043f3d9af3efa407665b47f8378ec691ba18
- MISChttps://git.kernel.org/stable/c/ea0697129807d718037f618221037aa0660ee3c5
- MISChttps://git.kernel.org/stable/c/c6d191164dc81838d8dbf452a6000f68c558d1ae
- MISChttps://git.kernel.org/stable/c/326941b22806cbf2df1fbfe902b7908b368cce42