From: Pavel Begunkov <asml.silence@gmail.com> mainline inclusion from mainline-v5.12-rc5 commit d81269fecb8ce16eb07efafc9ff5520b2a31c486 category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27 CVE: NA --------------------------- 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/562376a39509e260d8532186a06226e56eb1f594.161614923... Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: yangerkun <yangerkun@huawei.com> Reviewed-by: zhangyi (F) <yi.zhang@huawei.com> Signed-off-by: Cheng Jian <cj.chengjian@huawei.com> --- fs/io_uring.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 509ccdacab70..be440687fdb9 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3159,6 +3159,7 @@ 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; @@ -3172,7 +3173,8 @@ 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); -- 2.25.1