From 50b617ba788e5c27dfc6efc90556cdcc9509028d Mon Sep 17 00:00:00 2001 From: Hui Peng Date: Sat, 19 Sep 2026 11:25:23 +0000 Subject: [PATCH] io_uring/bpf_filter: mark source as COW when cloning filters io_bpf_filter_clone() shares the filter table between source and destination and marks the destination as needing a copy before it can be modified, but leaves the source as is. Registering another filter on the source then modifies the shared table in place, and the change shows up in everything that cloned it. Mark the source as COW as well. Fixes: ed82f35b926b ("io_uring: allow registration of per-task restrictions") Assisted-by: LLM Signed-off-by: Hui Peng Link: https://patch.msgid.link/20260919112523.3872581-1-benquike@gmail.com [axboe: edited patch and commit message] Signed-off-by: Jens Axboe --- io_uring/bpf_filter.c | 1 + 1 file changed, 1 insertion(+) diff --git a/io_uring/bpf_filter.c b/io_uring/bpf_filter.c index c0037632b7af..4a21511c4811 100644 --- a/io_uring/bpf_filter.c +++ b/io_uring/bpf_filter.c @@ -253,6 +253,7 @@ void io_bpf_filter_clone(struct io_restriction *dst, struct io_restriction *src) * If the src filter is going away, just ignore it. */ if (refcount_inc_not_zero(&src->bpf_filters->refs)) { + src->bpf_filters_cow = true; dst->bpf_filters = src->bpf_filters; dst->bpf_filters_cow = true; }