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| author | Gianfranco Trad <gianf.trad@gmail.com> | 2024-09-25 09:46:15 +0200 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2024-10-02 14:32:37 +0200 |
| commit | 264db9d666ad9a35075cc9ed9ec09d021580fbb1 (patch) | |
| tree | 8964eb4c10163f39f92e9f56260ad28731fbf956 /fs/udf | |
| parent | c226964ec786f3797ed389a16392ce4357697d24 (diff) | |
| download | lwn-264db9d666ad9a35075cc9ed9ec09d021580fbb1.tar.gz lwn-264db9d666ad9a35075cc9ed9ec09d021580fbb1.zip | |
udf: fix uninit-value use in udf_get_fileshortad
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@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=8901c4560b7ab5c2f9df
Tested-by: syzbot+8901c4560b7ab5c2f9df@syzkaller.appspotmail.com
Suggested-by: Jan Kara <jack@suse.com>
Signed-off-by: Gianfranco Trad <gianf.trad@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20240925074613.8475-3-gianf.trad@gmail.com
Diffstat (limited to 'fs/udf')
| -rw-r--r-- | fs/udf/inode.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/fs/udf/inode.c b/fs/udf/inode.c index 75c8cccfebd4..70c907fe8af9 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -2255,12 +2255,15 @@ 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) { |