This is a note to let you know that I've just added the patch titled
fs: ext4: initialize fsdata in pagecache_write()
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fs-ext4-initialize-fsdata-in-pagecache_write.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3311e1aa8f8765434003bbf646bd4ddd16c9ead1
Author: Alexander Potapenko <glider@xxxxxxxxxx>
Date: Mon Nov 21 12:21:30 2022 +0100
fs: ext4: initialize fsdata in pagecache_write()
[ Upstream commit 956510c0c7439e90b8103aaeaf4da92878c622f0 ]
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: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c
index 0c67b7060eb4..9879ea046e5a 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 = pagecache_write_begin(NULL, inode->i_mapping, pos, n, 0,
