diff options
| author | Pavel Begunkov <asml.silence@gmail.com> | 2021-03-19 10:21:19 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-03-30 14:32:06 +0200 |
| commit | dcf2dfc1614d64bc3366bdeeb302f32bc2050c4a (patch) | |
| tree | e3883f89890eb35cbb69446645f2135ebd47ea8f /fs/io_uring.c | |
| parent | efb334c4e5ffd98d1de9d0ede16703ced913ad71 (diff) | |
io_uring: fix provide_buffers sign extension
[ Upstream commit d81269fecb8ce16eb07efafc9ff5520b2a31c486 ]
io_provide_buffers_prep()'s "p->len * p->nbufs" to sign extension
problems. Not a huge problem as it's only used for access_ok() and
increases the checked length, but better to keep typing right.
Reported-by: Colin Ian King <colin.king@canonical.com>
Fixes: efe68c1ca8f49 ("io_uring: validate the full range of provided buffers for access")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/562376a39509e260d8532186a06226e56eb1f594.1616149233.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/io_uring.c')
| -rw-r--r-- | fs/io_uring.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 06e9c2181995..dde290eb7dd0 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3996,6 +3996,7 @@ static int io_remove_buffers(struct io_kiocb *req, bool force_nonblock, static int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { + unsigned long size; struct io_provide_buf *p = &req->pbuf; u64 tmp; @@ -4009,7 +4010,8 @@ static int io_provide_buffers_prep(struct io_kiocb *req, p->addr = READ_ONCE(sqe->addr); p->len = READ_ONCE(sqe->len); - if (!access_ok(u64_to_user_ptr(p->addr), (p->len * p->nbufs))) + size = (unsigned long)p->len * p->nbufs; + if (!access_ok(u64_to_user_ptr(p->addr), size)) return -EFAULT; p->bgid = READ_ONCE(sqe->buf_group); |