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| author | David Howells <dhowells@redhat.com> | 2023-02-27 13:04:54 +0000 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2023-03-01 18:18:25 -0600 |
| commit | 4c0421fa6df136ff869a078594b4b7b7637e566a (patch) | |
| tree | c9bf0849cee10a480fad111f25726deb6a8e7655 /fs | |
| parent | 0268792f77d2e4ba8e056173bdf2f9af9963be76 (diff) | |
| download | lwn-4c0421fa6df136ff869a078594b4b7b7637e566a.tar.gz lwn-4c0421fa6df136ff869a078594b4b7b7637e566a.zip | |
iov: Fix netfs_extract_user_to_sg()
Fix the loop check in netfs_extract_user_to_sg() for extraction from
user-backed iterators to do the body if npages > 0, not if npages < 0
(which it can never be).
This isn't currently used by cifs, which only ever extracts data from BVEC,
KVEC and XARRAY iterators at this level, user-backed iterators having being
decanted into BVEC iterators at a higher level to accommodate the work
being done in a kernel thread.
Found by smatch:
fs/netfs/iterator.c:139 netfs_extract_user_to_sg() warn: unsigned 'npages' is never less than zero.
Fixes: 018584697533 ("netfs: Add a function to extract an iterator into a scatterlist")
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202302261115.P3TQi1ZO-lkp@intel.com/
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/Y/yYnAhoAYDBKixX@kili
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: linux-cachefs@redhat.com
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/netfs/iterator.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/netfs/iterator.c b/fs/netfs/iterator.c index f00d43b8ac0a..e9a45dea748a 100644 --- a/fs/netfs/iterator.c +++ b/fs/netfs/iterator.c @@ -134,7 +134,7 @@ static ssize_t netfs_extract_user_to_sg(struct iov_iter *iter, npages = DIV_ROUND_UP(off + len, PAGE_SIZE); sg_max -= npages; - for (; npages < 0; npages--) { + for (; npages > 0; npages--) { struct page *page = *pages; size_t seg = min_t(size_t, PAGE_SIZE - off, len); |