From: Pavel Begunkov Date: Wed, 24 Mar 2021 22:59:01 +0000 (+0000) Subject: io_uring: reg buffer overflow checks hardening X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=50e96989d736b8e5623059815247be01ca6713c1;p=linux.git io_uring: reg buffer overflow checks hardening We are safe with overflows in io_sqe_buffer_register() because it will just yield alloc failure, but it's nicer to check explicitly. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/2b0625551be3d97b80a5fd21c8cd79dc1c91f0b5.1616624589.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- diff --git a/fs/io_uring.c b/fs/io_uring.c index 852f9e908904b..2be6f3f9578fe 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8404,6 +8404,8 @@ static int io_buffers_map_alloc(struct io_ring_ctx *ctx, unsigned int nr_args) static int io_buffer_validate(struct iovec *iov) { + unsigned long tmp, acct_len = iov->iov_len + (PAGE_SIZE - 1); + /* * Don't impose further limits on the size and buffer * constraints here, we'll -EINVAL later when IO is @@ -8416,6 +8418,9 @@ static int io_buffer_validate(struct iovec *iov) if (iov->iov_len > SZ_1G) return -EFAULT; + if (check_add_overflow((unsigned long)iov->iov_base, acct_len, &tmp)) + return -EOVERFLOW; + return 0; }