This is a note to let you know that I've just added the patch titled io_uring: clean rings on NO_MMAP alloc fail to the 6.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: io_uring-clean-rings-on-no_mmap-alloc-fail.patch and it can be found in the queue-6.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c5c1020214aec6127b91ecfe4a505bc98720abe4 Author: Pavel Begunkov <asml.silence@xxxxxxxxx> Date: Tue Mar 12 14:56:27 2024 +0000 io_uring: clean rings on NO_MMAP alloc fail [ Upstream commit cef59d1ea7170ec753182302645a0191c8aa3382 ] We make a few cancellation judgements based on ctx->rings, so let's zero it afer deallocation for IORING_SETUP_NO_MMAP just like it's done with the mmap case. Likely, it's not a real problem, but zeroing is safer and better tested. Cc: stable@xxxxxxxxxxxxxxx Fixes: 03d89a2de25bbc ("io_uring: support for user allocated memory for rings/sqes") Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx> Link: https://lore.kernel.org/r/9ff6cdf91429b8a51699c210e1f6af6ea3f8bdcf.1710255382.git.asml.silence@xxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 9f938874c5e13..adf944bb5a2fe 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -2776,14 +2776,15 @@ static void io_rings_free(struct io_ring_ctx *ctx) if (!(ctx->flags & IORING_SETUP_NO_MMAP)) { io_mem_free(ctx->rings); io_mem_free(ctx->sq_sqes); - ctx->rings = NULL; - ctx->sq_sqes = NULL; } else { io_pages_free(&ctx->ring_pages, ctx->n_ring_pages); ctx->n_ring_pages = 0; io_pages_free(&ctx->sqe_pages, ctx->n_sqe_pages); ctx->n_sqe_pages = 0; } + + ctx->rings = NULL; + ctx->sq_sqes = NULL; } void *io_mem_alloc(size_t size)