From 7e6621b99d20f26f7355a7f266bebd6f5ce88693 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 5 Dec 2023 07:02:13 -0700 Subject: io_uring/kbuf: check for buffer list readiness after NULL check [ Upstream commit 9865346b7e8374b57f1c3ccacdc77846c6352ff4 ] Move the buffer list 'is_ready' check below the validity check for the buffer list for a given group. Fixes: 5cf4f52e6d8a ("io_uring: free io_buffer_list entries via RCU") Reported-by: Dan Carpenter Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- io_uring/kbuf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'io_uring') diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index 12eec4778c5b..e8516f3bbbaa 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -743,6 +743,8 @@ void *io_pbuf_get_address(struct io_ring_ctx *ctx, unsigned long bgid) bl = __io_buffer_get_list(ctx, smp_load_acquire(&ctx->io_bl), bgid); + if (!bl || !bl->is_mmap) + return NULL; /* * Ensure the list is fully setup. Only strictly needed for RCU lookup * via mmap, and in that case only for the array indexed groups. For @@ -750,8 +752,6 @@ void *io_pbuf_get_address(struct io_ring_ctx *ctx, unsigned long bgid) */ if (!smp_load_acquire(&bl->is_ready)) return NULL; - if (!bl || !bl->is_mmap) - return NULL; return bl->buf_ring; } -- cgit v1.2.3