CVE-2024-26752 — l2tp: pass correct message length to ip6_append_data

Description (CNA)

In the Linux kernel, the following vulnerability has been resolved: l2tp: pass correct message length to ip6_append_data l2tp_ip6_sendmsg needs to avoid accounting for the transport header twice when splicing more data into an already partially-occupied skbuff. To manage this, we check whether the skbuff contains data using skb_queue_empty when deciding how much data to append using ip6_append_data. However, the code which performed the calculation was incorrect: ulen = len + skb_queue_empty(&sk->sk_write_queue) ? transhdrlen : 0; ...due to C operator precedence, this ends up setting ulen to transhdrlen for messages with a non-zero length, which results in corrupted packets on the wire. Add parentheses to correct the calculation in line with the original intent.

Affected (CNA)

Vendor / product	Versions
Linux / Linux	affected 559d697c5d072593d22b3e0bd8b8081108aeaf59 before 4c3ce64bc9d36ca9164dd6c77ff144c121011aae; affected 1fc793d68d50dee4782ef2e808913d5dd880bcc6 before c1d3a84a67db910ce28a871273c992c3d7f9efb5; affected 96b2e1090397217839fcd6c9b6d8f5d439e705ed before dcb4d14268595065c85dc5528056713928e17243; affected cd1189956393bf850b2e275e37411855d3bd86bb before 0da15a70395182ee8cb75716baf00dddc0bea38d; affected f6a7182179c0ed788e3755ee2ed18c888ddcc33f before 13cd1daeea848614e585b2c6ecc11ca9c8ab2500; affected 9d4c75800f61e5d75c1659ba201b6c0c7ead3070 before 804bd8650a3a2bf3432375f8c97d5049d845ce56; affected 9d4c75800f61e5d75c1659ba201b6c0c7ead3070 before 83340c66b498e49353530e41542500fc8a4782d6; affected 9d4c75800f61e5d75c1659ba201b6c0c7ead3070 before 359e54a93ab43d32ee1bff3c2f9f10cb9f6b6e79; affected 7626b9fed53092aa2147978070e610ecb61af844; affected fe80658c08e3001c80c5533cd41abfbb0e0e28fd; affected 4.19.296 before 4.19.308; affected 5.4.258 before 5.4.270; affected 5.10.198 before 5.10.211; affected 5.15.135 before 5.15.150; affected 6.1.57 before 6.1.80; affected 4.14.327 before 4.15; affected 6.5.7 before 6.6
Linux / Linux	affected 6.6; unaffected 0 before 6.6; unaffected 4.19.308 through 4.19.; unaffected 5.4.270 through 5.4.; unaffected 5.10.211 through 5.10.; unaffected 5.15.150 through 5.15.; unaffected 6.1.80 through 6.1.; unaffected 6.6.19 through 6.6.; unaffected 6.7.7 through 6.7.; unaffected 6.8 through

Vendor / product

Versions

Linux / Linux

affected 559d697c5d072593d22b3e0bd8b8081108aeaf59 before 4c3ce64bc9d36ca9164dd6c77ff144c121011aae; affected 1fc793d68d50dee4782ef2e808913d5dd880bcc6 before c1d3a84a67db910ce28a871273c992c3d7f9efb5; affected 96b2e1090397217839fcd6c9b6d8f5d439e705ed before dcb4d14268595065c85dc5528056713928e17243; affected cd1189956393bf850b2e275e37411855d3bd86bb before 0da15a70395182ee8cb75716baf00dddc0bea38d; affected f6a7182179c0ed788e3755ee2ed18c888ddcc33f before 13cd1daeea848614e585b2c6ecc11ca9c8ab2500; affected 9d4c75800f61e5d75c1659ba201b6c0c7ead3070 before 804bd8650a3a2bf3432375f8c97d5049d845ce56; affected 9d4c75800f61e5d75c1659ba201b6c0c7ead3070 before 83340c66b498e49353530e41542500fc8a4782d6; affected 9d4c75800f61e5d75c1659ba201b6c0c7ead3070 before 359e54a93ab43d32ee1bff3c2f9f10cb9f6b6e79; affected 7626b9fed53092aa2147978070e610ecb61af844; affected fe80658c08e3001c80c5533cd41abfbb0e0e28fd; affected 4.19.296 before 4.19.308; affected 5.4.258 before 5.4.270; affected 5.10.198 before 5.10.211; affected 5.15.135 before 5.15.150; affected 6.1.57 before 6.1.80; affected 4.14.327 before 4.15; affected 6.5.7 before 6.6

Linux / Linux

affected 6.6; unaffected 0 before 6.6; unaffected 4.19.308 through 4.19.*; unaffected 5.4.270 through 5.4.*; unaffected 5.10.211 through 5.10.*; unaffected 5.15.150 through 5.15.*; unaffected 6.1.80 through 6.1.*; unaffected 6.6.19 through 6.6.*; unaffected 6.7.7 through 6.7.*; unaffected 6.8 through *

CWE

No CWE identifiers supplied.

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.

CVE

No English description supplied.