Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: tcp: ipv6: clamp default adverting MSS to avoid GSO_BY_FRAGS (0xFFFF) When MTU is large, ip6_default_advmss() can return IPV6_MAXPLEN (65535). This is interpreted by TCP as mss_clamp, allowing the MSS to reach 65535. However, 0xFFFF is also used as a magic value GSO_BY_FRAGS in the kernel. If a TCP packet with gso_size=0xFFFF is passed to skb_segment(), it will be mistakenly treated as GSO_BY_FRAGS, leading to a NULL pointer dereference because local TCP packets do not use frag_list. Fix this by returning min(IPV6_MAXPLEN, GSO_BY_FRAGS - 1) (65534) from ip6_default_advmss() when MTU is large. Also update the stale comment in ip6_default_advmss() which suggested that IPV6_MAXPLEN is returned to mean "any MSS".
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 3953c46c3ac7eef31a9935427371c6f54a22f1ba before 560b33b434e922ef97f9ff23aa2e909ef7aacd5c; affected 3953c46c3ac7eef31a9935427371c6f54a22f1ba before 21f69ac1879bb970588d5e7c12a96e6542f7c1a7; affected 3953c46c3ac7eef31a9935427371c6f54a22f1ba before c0db3dc2ac323b6c4b76adede3b355a9daa6dea8; affected 3953c46c3ac7eef31a9935427371c6f54a22f1ba before 572fff10819dfc359298d1f774839e76a4d96f93; affected 3953c46c3ac7eef31a9935427371c6f54a22f1ba before 8e6214a530c03e341dc1b0a846c8f2b716b3551a; affected 3953c46c3ac7eef31a9935427371c6f54a22f1ba before d774cdbda6634a78d0f2baf201ee5a8c57f3bc0e; affected 3953c46c3ac7eef31a9935427371c6f54a22f1ba before a210791f33345aa87187f7d7a9f3b9b7f4a28e6d; affected 3953c46c3ac7eef31a9935427371c6f54a22f1ba before 2bf43d0e2e6a27d52a7d624e2d6b9116972e8a22 |
| Linux / Linux | affected 4.8; unaffected 0 before 4.8; unaffected 5.10.261 through 5.10.*; unaffected 5.15.212 through 5.15.*; unaffected 6.1.178 through 6.1.*; unaffected 6.6.145 through 6.6.*; unaffected 6.12.97 through 6.12.*; unaffected 6.18.40 through 6.18.*; unaffected 7.1.5 through 7.1.*; unaffected 7.2 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/560b33b434e922ef97f9ff23aa2e909ef7aacd5c
- https://git.kernel.org/stable/c/21f69ac1879bb970588d5e7c12a96e6542f7c1a7
- https://git.kernel.org/stable/c/c0db3dc2ac323b6c4b76adede3b355a9daa6dea8
- https://git.kernel.org/stable/c/572fff10819dfc359298d1f774839e76a4d96f93
- https://git.kernel.org/stable/c/8e6214a530c03e341dc1b0a846c8f2b716b3551a
- https://git.kernel.org/stable/c/d774cdbda6634a78d0f2baf201ee5a8c57f3bc0e
- https://git.kernel.org/stable/c/a210791f33345aa87187f7d7a9f3b9b7f4a28e6d
- https://git.kernel.org/stable/c/2bf43d0e2e6a27d52a7d624e2d6b9116972e8a22
ADP enrichment
No English description supplied.
No references supplied.