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@xxxxxxxxx> Reported-by: Dan Carpenter <error27@xxxxxxxxx> Signed-off-by: David Howells <dhowells@xxxxxxxxxx> cc: Steve French <sfrench@xxxxxxxxx> cc: Jeff Layton <jlayton@xxxxxxxxxx> cc: linux-cifs@xxxxxxxxxxxxxxx cc: linux-cachefs@xxxxxxxxxx Link: https://lore.kernel.org/oe-kbuild-all/202302261115.P3TQi1ZO-lkp@xxxxxxxxx/ --- fs/netfs/iterator.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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); -- Linux-cachefs mailing list Linux-cachefs@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/linux-cachefs