Commit 442ae406 authored by Jens Axboe's avatar Jens Axboe
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io_uring/kbuf: fix memory leak if io_buffer_add_list fails 



io_register_pbuf_ring() ignores the return value of io_buffer_add_list(),
which can fail if xa_store() returns an error (e.g., -ENOMEM). When this
happens, the function returns 0 (success) to the caller, but the
io_buffer_list structure is neither added to the xarray nor freed.

In practice this requires failure injection to hit, hence not a real
issue. But it should get fixed up none the less.

Fixes: c7fb1942 ("io_uring: add support for ring mapped supplied buffers")
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ccd18ce2

io_uring/kbuf.c

+3 −2
Original line number Diff line number Diff line
@@ -669,7 +669,8 @@ int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg) 
	bl->buf_ring = br;

	if (reg.flags & IOU_PBUF_RING_INC)

		bl->flags |= IOBL_INC;

	io_buffer_add_list(ctx, bl, reg.bgid);

	ret = io_buffer_add_list(ctx, bl, reg.bgid);

	if (!ret)

		return 0;

fail:

	io_free_region(ctx->user, &bl->region);