This is a note to let you know that I've just added the patch titled
udf: fix uninit-value use in udf_get_fileshortad
to the 5.15-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:
udf-fix-uninit-value-use-in-udf_get_fileshortad.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f2eccfb3f6c6aaeb2ea75bc46d998cd75d1429cb
Author: Gianfranco Trad <gianf.trad@xxxxxxxxx>
Date: Wed Sep 25 09:46:15 2024 +0200
udf: fix uninit-value use in udf_get_fileshortad
[ Upstream commit 264db9d666ad9a35075cc9ed9ec09d021580fbb1 ]
Check for overflow when computing alen in udf_current_aext to mitigate
later uninit-value use in udf_get_fileshortad KMSAN bug[1].
After applying the patch reproducer did not trigger any issue[2].
[1] https://syzkaller.appspot.com/bug?extid=8901c4560b7ab5c2f9df
[2] https://syzkaller.appspot.com/x/log.txt?x=10242227980000
Reported-by: syzbot+8901c4560b7ab5c2f9df@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=8901c4560b7ab5c2f9df
Tested-by: syzbot+8901c4560b7ab5c2f9df@xxxxxxxxxxxxxxxxxxxxxxxxx
Suggested-by: Jan Kara <jack@xxxxxxxx>
Signed-off-by: Gianfranco Trad <gianf.trad@xxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Link: https://patch.msgid.link/20240925074613.8475-3-gianf.trad@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 443d747bcec2e..81bd01ea89eb6 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -2112,12 +2112,15 @@ int udf_current_aext(struct inode *inode, struct extent_position *epos,
alen = udf_file_entry_alloc_offset(inode) +
iinfo->i_lenAlloc;
} else {
+ struct allocExtDesc *header =
+ (struct allocExtDesc *)epos->bh->b_data;
+
if (!epos->offset)
epos->offset = sizeof(struct allocExtDesc);
ptr = epos->bh->b_data + epos->offset;
- alen = sizeof(struct allocExtDesc) +
- le32_to_cpu(((struct allocExtDesc *)epos->bh->b_data)->
- lengthAllocDescs);
+ if (check_add_overflow(sizeof(struct allocExtDesc),
+ le32_to_cpu(header->lengthAllocDescs), &alen))
+ return -1;
}
switch (iinfo->i_alloc_type) {
