Vulnerability Details CVE-2026-31484
In the Linux kernel, the following vulnerability has been resolved:
io_uring/fdinfo: fix OOB read in SQE_MIXED wrap check
__io_uring_show_fdinfo() iterates over pending SQEs and, for 128-byte
SQEs on an IORING_SETUP_SQE_MIXED ring, needs to detect when the second
half of the SQE would be past the end of the sq_sqes array. The current
check tests (++sq_head & sq_mask) == 0, but sq_head is only incremented
when a 128-byte SQE is encountered, not on every iteration. The actual
array index is sq_idx = (i + sq_head) & sq_mask, which can be sq_mask
(the last slot) while the wrap check passes.
Fix by checking sq_idx directly. Keep the sq_head increment so the loop
still skips the second half of the 128-byte SQE on the next iteration.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 2.9%
CVSS Severity
CVSS v3 Score 7.1
References
Products affected by CVE-2026-31484
-
cpe:2.3:o:linux:linux_kernel:6.19
-
cpe:2.3:o:linux:linux_kernel:6.19.1
-
cpe:2.3:o:linux:linux_kernel:6.19.10
-
cpe:2.3:o:linux:linux_kernel:6.19.3
-
cpe:2.3:o:linux:linux_kernel:6.19.4
-
cpe:2.3:o:linux:linux_kernel:6.19.6
-
cpe:2.3:o:linux:linux_kernel:6.19.7
-
cpe:2.3:o:linux:linux_kernel:6.19.8
-
cpe:2.3:o:linux:linux_kernel:6.19.9
-
cpe:2.3:o:linux:linux_kernel:7.0