Re: [PATCH][next][V2] io_uring: Fix incorrect sizeof operator for copy_from_user call
From: Pavel Begunkov <asml.silence@gmail.com>
Date: 2021-06-15 13:36:13
Also in:
kernel-janitors, lkml
On 6/15/21 2:00 PM, Colin King wrote:
From: Colin Ian King <redacted>
Static analysis is warning that the sizeof being used is should be
of *data->tags[i] and not data->tags[i]. Although these are the same
size on 64 bit systems it is not a portable assumption to assume
this is true for all cases. Fix this by using a temporary pointer
tag_slot to make the code a clearer.
Addresses-Coverity: ("Sizeof not portable")
Fixes: d878c81610e1 ("io_uring: hide rsrc tag copy into generic helpers")
Signed-off-by: Colin Ian King <redacted>Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
quoted hunk ↗ jump to hunk
--- V2: Use temp variable tag_slot, this makes code clearer as suggested by Pavel Begunkov. --- fs/io_uring.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)diff --git a/fs/io_uring.c b/fs/io_uring.c index d665c9419ad3..7538d0878ff5 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c@@ -7230,8 +7230,10 @@ static int io_rsrc_data_alloc(struct io_ring_ctx *ctx, rsrc_put_fn *do_put, if (utags) { ret = -EFAULT; for (i = 0; i < nr; i++) { - if (copy_from_user(io_get_tag_slot(data, i), &utags[i], - sizeof(data->tags[i]))) + u64 *tag_slot = io_get_tag_slot(data, i); + + if (copy_from_user(tag_slot, &utags[i], + sizeof(*tag_slot))) goto fail; } }
-- Pavel Begunkov