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Date: Sat, 02 Mar 2024 15:34:21 -0800
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Subject: Re: [syzbot] [hfs?] KMSAN: uninit-value in hfs_cat_keycmp (2)
From: syzbot <syzbot+04486d87f6240a004c85@syzkaller.appspotmail.com>
To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, 
	syzkaller-bugs@googlegroups.com
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syzbot has found a reproducer for the following issue on:

HEAD commit:    5ad3cb0ed525 Merge tag 'for-v6.8-rc2' of git://git.kernel...
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=14fa7b8c180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=80c7a82a572c0de3
dashboard link: https://syzkaller.appspot.com/bug?extid=04486d87f6240a004c85
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=116f5a6a180000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16cb9306180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a148235ac5b1/disk-5ad3cb0e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4b06f4d02ad6/vmlinux-5ad3cb0e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7fff06beed25/bzImage-5ad3cb0e.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/0c762eef88b9/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+04486d87f6240a004c85@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 64
hfs: filesystem is marked locked, mounting read-only.
=====================================================
BUG: KMSAN: uninit-value in hfs_cat_keycmp+0x154/0x210 fs/hfs/catalog.c:178
 hfs_cat_keycmp+0x154/0x210 fs/hfs/catalog.c:178
 __hfs_brec_find+0x250/0x820 fs/hfs/bfind.c:75
 hfs_brec_find+0x436/0x970 fs/hfs/bfind.c:138
 hfs_brec_read+0x3f/0x1a0 fs/hfs/bfind.c:165
 hfs_cat_find_brec+0xe6/0x400 fs/hfs/catalog.c:194
 hfs_fill_super+0x1f27/0x23c0 fs/hfs/super.c:419
 mount_bdev+0x38f/0x510 fs/super.c:1658
 hfs_mount+0x4d/0x60 fs/hfs/super.c:456
 legacy_get_tree+0x110/0x290 fs/fs_context.c:662
 vfs_get_tree+0xa5/0x560 fs/super.c:1779
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352
 path_mount+0x73d/0x1f20 fs/namespace.c:3679
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x725/0x810 fs/namespace.c:3875
 __x64_sys_mount+0xe4/0x140 fs/namespace.c:3875
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:3819 [inline]
 slab_alloc_node mm/slub.c:3860 [inline]
 __do_kmalloc_node mm/slub.c:3980 [inline]
 __kmalloc+0x919/0xf80 mm/slub.c:3994
 kmalloc include/linux/slab.h:594 [inline]
 hfs_find_init+0x91/0x250 fs/hfs/bfind.c:21
 hfs_fill_super+0x1eb9/0x23c0 fs/hfs/super.c:416
 mount_bdev+0x38f/0x510 fs/super.c:1658
 hfs_mount+0x4d/0x60 fs/hfs/super.c:456
 legacy_get_tree+0x110/0x290 fs/fs_context.c:662
 vfs_get_tree+0xa5/0x560 fs/super.c:1779
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352
 path_mount+0x73d/0x1f20 fs/namespace.c:3679
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x725/0x810 fs/namespace.c:3875
 __x64_sys_mount+0xe4/0x140 fs/namespace.c:3875
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

CPU: 1 PID: 5019 Comm: syz-executor380 Not tainted 6.8.0-rc6-syzkaller-00238-g5ad3cb0ed525 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
=====================================================


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#syz test: git://repo/address.git branch-or-commit-hash
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