From 1b6b3bad09517a10adaae7b2ec92e7a6fb3c25fa Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Tue, 25 Feb 2025 22:59:22 +0900 Subject: [PATCH] bpf, test_run: Fix LIVE_FRAME frame update after a page has been recycled MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit BugLink: https://bugs.launchpad.net/bugs/2099996 [ Upstream commit c40dd8c4732551605712985bc5b7045094c6458d ] The test_run code detects whether a page has been modified and re-initialises the xdp_frame structure if it has, using xdp_update_frame_from_buff(). However, xdp_update_frame_from_buff() doesn't touch frame->mem, so that wasn't correctly re-initialised, which led to the pages from page_pool not being returned correctly. Syzbot noticed this as a memory leak. Fix this by also copying the frame->mem structure when re-initialising the frame, like we do on initialisation of a new page from page_pool. Fixes: e5995bc7e2ba ("bpf, test_run: fix crashes due to XDP frame overwriting/corruption") Fixes: b530e9e1063e ("bpf: Add "live packet" mode for XDP in BPF_PROG_RUN") Reported-by: syzbot+d121e098da06af416d23@syzkaller.appspotmail.com Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Daniel Borkmann Tested-by: syzbot+d121e098da06af416d23@syzkaller.appspotmail.com Reviewed-by: Alexander Lobakin Acked-by: Stanislav Fomichev Link: https://lore.kernel.org/bpf/20241030-test-run-mem-fix-v1-1-41e88e8cae43@redhat.com Signed-off-by: Sasha Levin Signed-off-by: Koichiro Den Signed-off-by: Stefan Bader --- net/bpf/test_run.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 2c6d53ae4280..ca397f454eec 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -244,6 +244,7 @@ static void reset_ctx(struct xdp_page_head *head) head->ctx.data_meta = head->orig_ctx.data_meta; head->ctx.data_end = head->orig_ctx.data_end; xdp_update_frame_from_buff(&head->ctx, head->frame); + head->frame->mem = head->orig_ctx.rxq->mem; } static int xdp_recv_frames(struct xdp_frame **frames, int nframes,