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authorLinus Torvalds <torvalds@linux-foundation.org>2017-05-09 09:01:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-05-09 09:01:21 -0700
commit339fbf6796f8e74544091adbf511286768eaf93e (patch)
tree12840783d0eb70d1a7ecd13c3a7fab5b69b0a2b6
parent8ee74a91ac304ad2e9e794eb96ed76f0634dec40 (diff)
parent5b47d59af68a8735e4637bacedcb4baf6f47c73f (diff)
Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fix from Al Viro: "Braino fix for iov_iter_revert() misuse" * 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fix braino in generic_file_read_iter()
-rw-r--r--lib/iov_iter.c2
-rw-r--r--mm/filemap.c2
2 files changed, 3 insertions, 1 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index ae82d9cea553..f835964c9485 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -790,6 +790,8 @@ void iov_iter_revert(struct iov_iter *i, size_t unroll)
{
if (!unroll)
return;
+ if (WARN_ON(unroll > MAX_RW_COUNT))
+ return;
i->count += unroll;
if (unlikely(i->type & ITER_PIPE)) {
struct pipe_inode_info *pipe = i->pipe;
diff --git a/mm/filemap.c b/mm/filemap.c
index b7b973b47d8d..6f1be573a5e6 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2050,7 +2050,7 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
iocb->ki_pos += retval;
count -= retval;
}
- iov_iter_revert(iter, iov_iter_count(iter) - count);
+ iov_iter_revert(iter, count - iov_iter_count(iter));
/*
* Btrfs can have a short DIO read if we encounter