Re: [syzbot] [exfat?] KMSAN: uninit-value in vfat_rename2

[OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>]

syzbot <syzbot+ef0d7bc412553291aa86@syzkaller.appspotmail.com> writes:

> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    e7ed34365879 Merge tag 'mailbox-v6.12' of git://git.kernel..
> git tree:       upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=11b54ea9980000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=92da5062b0d65389
> dashboard link: https://syzkaller.appspot.com/bug?extid=ef0d7bc412553291aa86
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14b7ed07980000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=101dfd9f980000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/66cc3d8c5c10/disk-e7ed3436.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/c7769a88b445/vmlinux-e7ed3436.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/c1fe4c6ee436/bzImage-e7ed3436.xz
> mounted in repro #1: https://storage.googleapis.com/syzbot-assets/2ab98c65fd49/mount_0.gz
> mounted in repro #2: https://storage.googleapis.com/syzbot-assets/7ffc0eb73060/mount_5.gz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+ef0d7bc412553291aa86@syzkaller.appspotmail.com

The patch fixes this bug. Please apply.
Thanks.


From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Subject: [PATCH] fat: Fix uninitialized variable
Date: Fri, 04 Oct 2024 15:03:49 +0900

Reported-by: syzbot+ef0d7bc412553291aa86@syzkaller.appspotmail.com
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
---
 fs/fat/namei_vfat.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index 6423e1d..15bf32c 100644
--- a/fs/fat/namei_vfat.c	2024-10-04 14:51:50.473038530 +0900
+++ b/fs/fat/namei_vfat.c	2024-10-04 14:56:53.108618655 +0900
@@ -1037,7 +1037,7 @@ error_inode:
 	if (corrupt < 0) {
 		fat_fs_error(new_dir->i_sb,
 			     "%s: Filesystem corrupted (i_pos %lld)",
-			     __func__, sinfo.i_pos);
+			     __func__, new_i_pos);
 	}
 	goto out;
 }
_

-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>