CVE-2026-74581

net: ipv6: clear suppressed fib6 rule result

State: Published
Severity: 9.8 Critical
Published: Aug 21, 2026
Updated: Oct 16, 2026
Reserved: Aug 15, 2026

Description

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

net: ipv6: clear suppressed fib6 rule result

fib6_rule_suppress() drops a suppressed route with ip6_rt_put_flags(), but leaves res->rt6 pointing at the released rt6_info.

If no later rule supplies a replacement, fib6_rule_lookup() still sees res.rt6 and returns that stale dst to its caller. A suppressing rule can therefore leak a released route back to rt6_lookup(), and the next put hits rcuref_put_slowpath() from dst_release().

Clear res->rt6 when suppressing the route so suppressed lookups fall through to the null dst instead of reusing the released one.

Scores

CVSS	Score	Vector	Source
3.1	9.8 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	209d35ee34e25f9668c404350a1c86d914c54ffa to before 90c57310e266eb94e4a80d6b15a9ca131d2e82cbAffected 8ef8a76a340ebdb2c2eea3f6fb0ebbed09a16383 to before 5d29b286c9de0b309e94b9ed083aa1a2f429434fAffected cdef485217d30382f3bf6448c54b4401648fe3f1 to before 354db6243eca59e9d187ffbf8b7955b044ce84dcAffected cdef485217d30382f3bf6448c54b4401648fe3f1 to before 6d98c70fe0ba8c7708bfd5b2a5174d2086775daaAffected cdef485217d30382f3bf6448c54b4401648fe3f1 to before 9bad152c42b37499162367fe47867411e62fffa3Affected cdef485217d30382f3bf6448c54b4401648fe3f1 to before dc3ab04220667f254f4348572b2a0b3febff89fbAffected cdef485217d30382f3bf6448c54b4401648fe3f1 to before a341c091ca0bfae377747b1b59a3bd8ebe18a937Affected cdef485217d30382f3bf6448c54b4401648fe3f1 to before 6aea62e433fe1b586202a5fee8b5807ce635e1d7Affected ee38eb8cf9a7323884c2b8e0adbbeb2192d31e29Affected 5.10.84 to before 5.10.265Affected 5.15.7 to before 5.15.216Affected 5.4.164 to before 5.5Affected
LinuxLinux	5.16Affected before 5.16Not affected 5.10.265 through 5.10.Not affected 5.15.216 through 5.15.Not affected 6.1.183 through 6.1.Not affected 6.6.151 through 6.6.Not affected 6.12.103 through 6.12.Not affected 6.18.44 through 6.18.Not affected 7.1.8 through 7.1.*Not affected 7.2 and laterNot affected

Product

Versions

LinuxLinux

209d35ee34e25f9668c404350a1c86d914c54ffa to before 90c57310e266eb94e4a80d6b15a9ca131d2e82cbAffected
8ef8a76a340ebdb2c2eea3f6fb0ebbed09a16383 to before 5d29b286c9de0b309e94b9ed083aa1a2f429434fAffected
cdef485217d30382f3bf6448c54b4401648fe3f1 to before 354db6243eca59e9d187ffbf8b7955b044ce84dcAffected
cdef485217d30382f3bf6448c54b4401648fe3f1 to before 6d98c70fe0ba8c7708bfd5b2a5174d2086775daaAffected
cdef485217d30382f3bf6448c54b4401648fe3f1 to before 9bad152c42b37499162367fe47867411e62fffa3Affected
cdef485217d30382f3bf6448c54b4401648fe3f1 to before dc3ab04220667f254f4348572b2a0b3febff89fbAffected
cdef485217d30382f3bf6448c54b4401648fe3f1 to before a341c091ca0bfae377747b1b59a3bd8ebe18a937Affected
cdef485217d30382f3bf6448c54b4401648fe3f1 to before 6aea62e433fe1b586202a5fee8b5807ce635e1d7Affected
ee38eb8cf9a7323884c2b8e0adbbeb2192d31e29Affected
5.10.84 to before 5.10.265Affected
5.15.7 to before 5.15.216Affected
5.4.164 to before 5.5Affected

LinuxLinux

5.16Affected
before 5.16Not affected
5.10.265 through 5.10.*Not affected
5.15.216 through 5.15.*Not affected
6.1.183 through 6.1.*Not affected
6.6.151 through 6.6.*Not affected
6.12.103 through 6.12.*Not affected
6.18.44 through 6.18.*Not affected
7.1.8 through 7.1.*Not affected
7.2 and laterNot affected

References

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