CVE-2022-49325

Summary

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

tcp: add accessors to read/set tp->snd_cwnd

We had various bugs over the years with code breaking the assumption that tp->snd_cwnd is greater than zero.

Lately, syzbot reported the WARN_ON_ONCE(!tp->prior_cwnd) added in commit 8b8a321ff72c ("tcp: fix zero cwnd in tcp_cwnd_reduction") can trigger, and without a repro we would have to spend considerable time finding the bug.

Instead of complaining too late, we want to catch where and when tp->snd_cwnd is set to an illegal value.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux5d424d5a674f782d0659a3b66d951f412901faee < 3308676ec525901bf1656014003c443a60730a04affected
LinuxLinux5d424d5a674f782d0659a3b66d951f412901faee < 5aba0ad44fb4a7fb78c5076c313456de199a3c29affected
LinuxLinux5d424d5a674f782d0659a3b66d951f412901faee < 41e191fe72282e193a7744e2fc1786b23156c9e4affected
LinuxLinux5d424d5a674f782d0659a3b66d951f412901faee < 40570375356c874b1578e05c1dcc3ff7c1322dbeaffected
LinuxLinux2.6.17affected
LinuxLinux0 < 2.6.17unaffected
LinuxLinux5.15.47 <= 5.15.*unaffected
LinuxLinux5.17.15 <= 5.17.*unaffected
LinuxLinux5.18.4 <= 5.18.*unaffected
LinuxLinux5.19 <= *unaffected

Weaknesses

References