From: Alexander Potapenko Date: Mon, 21 Nov 2022 11:21:30 +0000 (+0100) Subject: fs: ext4: initialize fsdata in pagecache_write() X-Git-Tag: v6.0.18~44 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=48e3e1c2f6994c8ba2061e10dd880934fc74d61c;p=thirdparty%2Fkernel%2Fstable.git fs: ext4: initialize fsdata in pagecache_write() 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 Fixes: c93d8f885809 ("ext4: add basic fs-verity support") Reported-by: syzbot+9767be679ef5016b6082@syzkaller.appspotmail.com Signed-off-by: Alexander Potapenko Reviewed-by: Eric Biggers Link: https://lore.kernel.org/r/20221121112134.407362-1-glider@google.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c index 94442c690ca7d..47a132170f306 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);