CVE-2026-74704

Summary

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

net/sched: sch_cake: drop WARN_ON(1) for malformed packets in ACK filter

The sch_cake ACK filter parses packets to find the TCP header and filter duplicated ACKs if the flow is backlogged. The parsing code contains a WARN_ON(1) which can be triggered by a malformed IP header in certain cases. Depending on the system configuration, this leads either to either spamming dmesg with warnings, or a panic if panic_on_warn is set.

The code already correctly skips the offending packet in the branch that triggers the warning, so the WARN_ON itself doesn't really serve any purpose. So just drop it altogether to avoid the inconvenient side effects.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux8b7138814f29933898ecd31dfc83e35a30ee69f5 < c1693b7844a6c06d31a565e5a494948034dfd235affected
LinuxLinux8b7138814f29933898ecd31dfc83e35a30ee69f5 < a4b52612004a5639c4bfc30ba93ba414b8326e2aaffected
LinuxLinux8b7138814f29933898ecd31dfc83e35a30ee69f5 < ae1b2f8e21a41e7c7e75511bea0c4ccc59ec1bd3affected
LinuxLinux8b7138814f29933898ecd31dfc83e35a30ee69f5 < 0c4882bff34558d8d53fb04c3e96da5c327c7dc8affected
LinuxLinux8b7138814f29933898ecd31dfc83e35a30ee69f5 < 2504a76e5c0694e14e15562730e1339f2d9f9458affected
LinuxLinux8b7138814f29933898ecd31dfc83e35a30ee69f5 < cd2f1d9fe8a507c2dc86ad326fe221f121c47734affected
LinuxLinux8b7138814f29933898ecd31dfc83e35a30ee69f5 < a1ae353d8355407c1bea971d1c1af5e7f242bb7daffected
LinuxLinux8b7138814f29933898ecd31dfc83e35a30ee69f5 < 2a33516f9ef59ad11844d4fc152f889449b5daf3affected
LinuxLinux4.19affected
LinuxLinux0 < 4.19unaffected
LinuxLinux5.10.265 <= 5.10.*unaffected
LinuxLinux5.15.216 <= 5.15.*unaffected
LinuxLinux6.1.183 <= 6.1.*unaffected
LinuxLinux6.6.152 <= 6.6.*unaffected
LinuxLinux6.12.104 <= 6.12.*unaffected
LinuxLinux6.18.45 <= 6.18.*unaffected
LinuxLinux7.1.9 <= 7.1.*unaffected
LinuxLinux7.2 <= *unaffected

Weaknesses

References