Re: [PATCH] bpf: Fix UAF via mismatching bpf_prog/attachment RCU flavors

From: patchwork-bot+netdevbpf
Date: Tue Dec 10 2024 - 13:30:26 EST


Hello:

This patch was applied to bpf/bpf.git (master)
by Andrii Nakryiko <andrii@xxxxxxxxxx>:

On Tue, 10 Dec 2024 17:32:13 +0100 you wrote:
> Uprobes always use bpf_prog_run_array_uprobe() under tasks-trace-RCU
> protection. But it is possible to attach a non-sleepable BPF program to a
> uprobe, and non-sleepable BPF programs are freed via normal RCU (see
> __bpf_prog_put_noref()). This leads to UAF of the bpf_prog because a normal
> RCU grace period does not imply a tasks-trace-RCU grace period.
>
> Fix it by explicitly waiting for a tasks-trace-RCU grace period after
> removing the attachment of a bpf_prog to a perf_event.
>
> [...]

Here is the summary with links:
- bpf: Fix UAF via mismatching bpf_prog/attachment RCU flavors
https://git.kernel.org/bpf/bpf/c/ef1b808e3b7c

You are awesome, thank you!
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