From bc674a04c47cc23ad7e12893cad6226ea8f7a8ec Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Wed, 19 Feb 2025 10:08:01 +0000 Subject: [PATCH] io_uring/zcrx: recheck ifq on shutdown io_ring_exit_work() checks ifq before shutting it down and guarantees that the pointer is stable, but instead of relying on rather complicated synchronisation recheck the ifq pointer inside. Reported-by: Kees Bakker Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/905e55c47235ab26377a735294f939f31d00ae53.1739934175.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- io_uring/zcrx.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c index 026efb8dd3814..a9eaab3fccf21 100644 --- a/io_uring/zcrx.c +++ b/io_uring/zcrx.c @@ -489,9 +489,9 @@ void io_shutdown_zcrx_ifqs(struct io_ring_ctx *ctx) { lockdep_assert_held(&ctx->uring_lock); - if (ctx->ifq) - io_zcrx_scrub(ctx->ifq); - + if (!ctx->ifq) + return; + io_zcrx_scrub(ctx->ifq); io_close_queue(ctx->ifq); } -- 2.39.5