From: Alexander Potapenko <glider@xxxxxxxxxx> commit 956510c0c7439e90b8103aaeaf4da92878c622f0 upstream. 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> Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx> Link: https://lore.kernel.org/r/20221121112134.407362-1-glider@xxxxxxxxxx Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Cc: stable@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ext4/verity.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/ext4/verity.c +++ b/fs/ext4/verity.c @@ -76,7 +76,7 @@ static int pagecache_write(struct inode 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 = pagecache_write_begin(NULL, inode->i_mapping, pos, n, 0,