CVE-2026-98573

net: skbuff: fix pull-bound underflow in skb_checksum_setup_ipv6()

State: Published
Severity: Not scored
Published: Oct 18, 2026
Updated: Oct 19, 2026
Reserved: Sep 25, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

net: skbuff: fix pull-bound underflow in skb_checksum_setup_ipv6()

skb_maybe_pull_tail() subtracts skb_headlen(skb) from the unsigned max argument and passes the result to __pskb_pull_tail() as a signed int. The function does not ensure that max is at least skb_headlen(skb).

This can happen while parsing IPv6 extension headers when an skb already has a linear area larger than MAX_IPV6_HDR_LEN. Once the parser needs data beyond the linear area, max - skb_headlen(skb) wraps and is converted to a negative delta. __pskb_pull_tail() then passes that negative length to skb_copy_bits(), where it can become a very large copy length.

Pass the requested length itself as the pull bound at the three extension-header call sites, so the delta can no longer go negative.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before 9c4e432132a97b82edf28fa172c39f743e6bfb26Affected 1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before 718747afa5463d9cc5fd9a09f03b2a492edd9b78Affected 1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before a0ad0473c09d2e947aecac5c82e637ec85924b12Affected 1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before b2da5ed3d8c75e1b729a21b6d3beaed415e263f6Affected 1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before 6c28c31f051dbf49c71ba7ab7bb9bc905fa1d14bAffected 1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before cfa643f2ca36c6f913fe1a2ceb12412ebb0fd962Affected 1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before d7f474226809471dc7877435e9c492cc914df0bfAffected 1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before 3b4e0b0c008a8c1b474730248cd5b873026c74bdAffected
LinuxLinux	3.13Affected before 3.13Not affected 5.10.271 through 5.10.Not affected 5.15.222 through 5.15.Not affected 6.1.189 through 6.1.Not affected 6.6.158 through 6.6.Not affected 6.12.112 through 6.12.Not affected 6.18.55 through 6.18.Not affected 7.2.9 through 7.2.*Not affected 7.3 and laterNot affected

Product

Versions

LinuxLinux

1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before 9c4e432132a97b82edf28fa172c39f743e6bfb26Affected
1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before 718747afa5463d9cc5fd9a09f03b2a492edd9b78Affected
1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before a0ad0473c09d2e947aecac5c82e637ec85924b12Affected
1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before b2da5ed3d8c75e1b729a21b6d3beaed415e263f6Affected
1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before 6c28c31f051dbf49c71ba7ab7bb9bc905fa1d14bAffected
1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before cfa643f2ca36c6f913fe1a2ceb12412ebb0fd962Affected
1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before d7f474226809471dc7877435e9c492cc914df0bfAffected
1431fb31ecbaba1b5718006128f0f2ed0b94e1c3 to before 3b4e0b0c008a8c1b474730248cd5b873026c74bdAffected

LinuxLinux

3.13Affected
before 3.13Not affected
5.10.271 through 5.10.*Not affected
5.15.222 through 5.15.*Not affected
6.1.189 through 6.1.*Not affected
6.6.158 through 6.6.*Not affected
6.12.112 through 6.12.*Not affected
6.18.55 through 6.18.*Not affected
7.2.9 through 7.2.*Not affected
7.3 and laterNot affected

References

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