| From | Sasha Levin <> | Subject | [PATCH AUTOSEL 5.18 55/93] iov_iter_get_pages{,_alloc}(): cap the maxsize with MAX_RW_COUNT | Date | Thu, 11 Aug 2022 11:41:49 -0400 |
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From: Al Viro <viro@zeniv.linux.org.uk>
[ Upstream commit 7392ed1734c319150b5ddec3f192a6405728e8d0 ]
All callers can and should handle iov_iter_get_pages() returning fewer pages than requested. All in-kernel ones do. And it makes the arithmetical overflow analysis much simpler...
Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org> --- lib/iov_iter.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 0b64695ab632..ea588628828b 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1520,6 +1520,8 @@ ssize_t iov_iter_get_pages(struct iov_iter *i, maxsize = i->count; if (!maxsize) return 0; + if (maxsize > MAX_RW_COUNT) + maxsize = MAX_RW_COUNT; if (likely(iter_is_iovec(i))) { unsigned int gup_flags = 0; @@ -1640,6 +1642,8 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, maxsize = i->count; if (!maxsize) return 0; + if (maxsize > MAX_RW_COUNT) + maxsize = MAX_RW_COUNT; if (likely(iter_is_iovec(i))) { unsigned int gup_flags = 0; -- 2.35.1
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