CVE-2024-26752

Summary

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 Software

VendorProductVersion RangeStatus
LinuxLinux559d697c5d072593d22b3e0bd8b8081108aeaf59 < 4c3ce64bc9d36ca9164dd6c77ff144c121011aaeaffected
LinuxLinux1fc793d68d50dee4782ef2e808913d5dd880bcc6 < c1d3a84a67db910ce28a871273c992c3d7f9efb5affected
LinuxLinux96b2e1090397217839fcd6c9b6d8f5d439e705ed < dcb4d14268595065c85dc5528056713928e17243affected
LinuxLinuxcd1189956393bf850b2e275e37411855d3bd86bb < 0da15a70395182ee8cb75716baf00dddc0bea38daffected
LinuxLinuxf6a7182179c0ed788e3755ee2ed18c888ddcc33f < 13cd1daeea848614e585b2c6ecc11ca9c8ab2500affected
LinuxLinux9d4c75800f61e5d75c1659ba201b6c0c7ead3070 < 804bd8650a3a2bf3432375f8c97d5049d845ce56affected
LinuxLinux9d4c75800f61e5d75c1659ba201b6c0c7ead3070 < 83340c66b498e49353530e41542500fc8a4782d6affected
LinuxLinux9d4c75800f61e5d75c1659ba201b6c0c7ead3070 < 359e54a93ab43d32ee1bff3c2f9f10cb9f6b6e79affected
LinuxLinux7626b9fed53092aa2147978070e610ecb61af844affected
LinuxLinuxfe80658c08e3001c80c5533cd41abfbb0e0e28fdaffected
LinuxLinux4.19.296 < 4.19.308affected
LinuxLinux5.4.258 < 5.4.270affected
LinuxLinux5.10.198 < 5.10.211affected
LinuxLinux5.15.135 < 5.15.150affected
LinuxLinux6.1.57 < 6.1.80affected
LinuxLinux4.14.327 < 4.15affected
LinuxLinux6.5.7 < 6.6affected
LinuxLinux6.6affected
LinuxLinux0 < 6.6unaffected
LinuxLinux4.19.308 <= 4.19.*unaffected
LinuxLinux5.4.270 <= 5.4.*unaffected
LinuxLinux5.10.211 <= 5.10.*unaffected
LinuxLinux5.15.150 <= 5.15.*unaffected
LinuxLinux6.1.80 <= 6.1.*unaffected
LinuxLinux6.6.19 <= 6.6.*unaffected
LinuxLinux6.7.7 <= 6.7.*unaffected
LinuxLinux6.8 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

CVE Program Container

Additional References

References