[PATCH 1/5] fs: ext4: initialize fsdata in pagecache_write()

[Alexander Potapenko]

When aops->write_begin() does not initialize fsdata, KMSAN reports
an error passing the latter to aops->write_end().

Fix this by unconditionally initializing fsdata.

Cc: Eric Biggers <ebiggers@xxxxxxxxxx>
Fixes: c93d8f885809 ("ext4: add basic fs-verity support")
Reported-by: syzbot+9767be679ef5016b6082@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
---
 fs/ext4/verity.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c
index 3c640bd7ecaeb..30e3b65798b50 100644
--- a/fs/ext4/verity.c
+++ b/fs/ext4/verity.c
@@ -79,7 +79,7 @@ static int pagecache_write(struct inode *inode, const void *buf, size_t count,
 		size_t n = min_t(size_t, count,
 				 PAGE_SIZE - offset_in_page(pos));
 		struct page *page;
-		void *fsdata;
+		void *fsdata = NULL;
 		int res;
 
 		res = aops->write_begin(NULL, mapping, pos, n, &page, &fsdata);
-- 
2.38.1.584.g0f3c55d4c2-goog