CVE-2026-80603

Published: September 3, 2026Last modified: September 3, 2026

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read parse_dcc() treats data_end as an inclusive end pointer, but its only caller passes data_limit = ib_ptr + datalen, which points one past the last valid byte. The newline search loop iterates while tmp <= data_end, so when no newline is present, *tmp is read at tmp == data_end, one byte beyond the region filled by skb_header_pointer(). irc_buffer is kmalloc'd as MAX_SEARCH_SIZE + 1 bytes and datalen is capped at MAX_SEARCH_SIZE, so the stray read does not fault. The byte is uninitialized or stale; if it contains an ASCII digit, simple_strtoul will consume it and produce a wrong DCC IP or port in the conntrack expectation. The extra allocation byte is also a fragile guard: if the cap or allocation size changes, this becomes a real out-of-bounds read. Change the loop and its post-loop check to use strict less-than, consistent with the caller's exclusive-end convention. Update the function comment accordingly.

Severity score breakdown

ParameterValue
Base score9.1
Attack VectorNETWORK
Attack complexityLOW
Privileges requiredNONE
User interactionNONE
ScopeUNCHANGED
ConfidentialityHIGH
Integrity impactHIGH
Availability impactNONE
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Status

ProductReleasePackageStatus
Alpaquita Linux23 LTSlinux-ltsFixed (6.1.182-r0)
25 LTSlinux-ltsFixed (6.12.103-r0)
Streamlinux-ltsFixed (6.18.43-r0)

References

ON THIS PAGE