From: Jens Axboe <axboe@kernel.dk> stable inclusion from stable-v6.6.7 commit 7e6621b99d20f26f7355a7f266bebd6f5ce88693 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8SSQ4 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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 <dan.carpenter@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- io_uring/kbuf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) 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; } -- 2.20.1