io_uring/kbuf: Fix an NULL vs IS_ERR() bug in io_alloc_pbuf_ring()

[ Upstream commit e53f7b54b1fdecae897f25002ff0cff04faab228 ]

The io_mem_alloc() function returns error pointers, not NULL.  Update
the check accordingly.

Fixes: b10b73c102a2 ("io_uring/kbuf: recycle freed mapped buffer ring entries")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/5ed268d3-a997-4f64-bd71-47faa92101ab@moroto.mountain
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c
index 012f622..12eec47 100644 (file)
--- a/io_uring/kbuf.c
+++ b/io_uring/kbuf.c
@@ -623,8 +623,8 @@ static int io_alloc_pbuf_ring(struct io_ring_ctx *ctx,
        ibf = io_lookup_buf_free_entry(ctx, ring_size);
        if (!ibf) {
                ptr = io_mem_alloc(ring_size);
-               if (!ptr)
-                       return -ENOMEM;
+               if (IS_ERR(ptr))
+                       return PTR_ERR(ptr);
 
                /* Allocate and store deferred free entry */
                ibf = kmalloc(sizeof(*ibf), GFP_KERNEL_ACCOUNT);