Bug 2555032 (CVE-2026-98631) - CVE-2026-98631 kernel: xsk: Use a 32-bit compare in xsk_map_gen_lookup
Summary: CVE-2026-98631 kernel: xsk: Use a 32-bit compare in xsk_map_gen_lookup
Keywords:
Status: NEW
Alias: CVE-2026-98631
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-10-18 15:40 UTC by OSIDB Bzimport
Modified: 2026-10-21 14:26 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


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Description OSIDB Bzimport 2026-10-18 15:40:26 UTC
In the Linux kernel, the following vulnerability has been resolved:

xsk: Use a 32-bit compare in xsk_map_gen_lookup

xsk_map_gen_lookup() loads a u32 key and compares it with max_entries
using BPF_JMP_IMM. BPF immediates are sign-extended to 64 bits, so a
max_entries value of 0x80000000 or higher becomes a threshold larger
than every zero-extended 32-bit key. An out-of-range index then skips
the bounds check and the generated lookup reads past xsk_map[].

Compare with BPF_JMP32_IMM so the check stays in 32-bit unsigned range.


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