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.
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.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Sun, 18 Oct 2026 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | xsk: Use a 32-bit compare in xsk_map_gen_lookup | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-18T15:19:53.529Z
Reserved: 2026-09-25T10:25:14.361Z
Link: CVE-2026-98631
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-18T16:17:16.180
Modified: 2026-10-18T16:17:16.180
Link: CVE-2026-98631
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.