io_uring: fix invalid error check after malloc

Now we allocate io_mapped_ubuf instead of bvec, so we clearly have to
check its address after allocation.

Fixes: 41edf1a5ec967 ("io_uring: keep table of pointers to ubufs")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d28eb1bc4384284f69dbce35b9f70c115ff6176f.1619392565.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index eef3733..b65a253 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8265,7 +8265,7 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
                goto done;
 
        imu = kvmalloc(struct_size(imu, bvec, nr_pages), GFP_KERNEL);
-       if (!imu->bvec)
+       if (!imu)
                goto done;
 
        ret = 0;