io_uring: fix free of unallocated buffer list

in the error path of io_register_pbuf_ring, only free bl if it was
allocated.

Reported-by: Dipanjan Das <mail.dipanjan.das@gmail.com>
Fixes: c7fb19428d ("io_uring: add support for ring mapped supplied buffers")
Signed-off-by: Dylan Yudaken <dylany@fb.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/all/CANX2M5bXKw1NaHdHNVqssUUaBCs8aBpmzRNVEYEvV0n44P7ioA@mail.gmail.com/
Link: https://lore.kernel.org/all/CANX2M5YiZBXU3L6iwnaLs-HHJXRvrxM8mhPDiMDF9Y9sAvOHUA@mail.gmail.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Dylan Yudaken 2022-07-21 04:01:15 -07:00 committed by Jens Axboe
parent d785a773be
commit ec8516f3b7

View file

@ -12931,7 +12931,7 @@ static int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg)
{
struct io_uring_buf_ring *br;
struct io_uring_buf_reg reg;
struct io_buffer_list *bl;
struct io_buffer_list *bl, *free_bl = NULL;
struct page **pages;
int nr_pages;
@ -12963,7 +12963,7 @@ static int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg)
if (bl->buf_nr_pages || !list_empty(&bl->buf_list))
return -EEXIST;
} else {
bl = kzalloc(sizeof(*bl), GFP_KERNEL);
free_bl = bl = kzalloc(sizeof(*bl), GFP_KERNEL);
if (!bl)
return -ENOMEM;
}
@ -12972,7 +12972,7 @@ static int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg)
struct_size(br, bufs, reg.ring_entries),
&nr_pages);
if (IS_ERR(pages)) {
kfree(bl);
kfree(free_bl);
return PTR_ERR(pages);
}