io_uring/kbuf: check for buffer list readiness after NULL check

Move the buffer list 'is_ready' check below the validity check for
the buffer list for a given group.

Fixes: 5cf4f52e6d ("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>
This commit is contained in:
Jens Axboe 2023-12-05 07:02:13 -07:00
parent e53f7b54b1
commit 9865346b7e

View File

@ -756,6 +756,8 @@ 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
@ -763,8 +765,6 @@ 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;
}