High · published February 26, 2025
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.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | < 5.15.47 | 5.15.47 |
| linux/linux_kernel | ≥ 5.16, < 5.17.15 | 5.17.15 |
| linux/linux_kernel | ≥ 5.18, < 5.18.4 | 5.18.4 |