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Date:   Fri, 25 Nov 2022 01:56:33 -0800
Message-ID: <0000000000005ad04005ee48897f@google.com>
Subject: [syzbot] KMSAN: uninit-value in hfs_revalidate_dentry
From:   syzbot <syzbot+3ae6be33a50b5aae4dab@syzkaller.appspotmail.com>
To:     glider@google.com, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
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Hello,

syzbot found the following issue on:

HEAD commit:    a472f15b3d1e kmsan: allow using __msan_instrument_asm_stor..
git tree:       https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=1206a7fd880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1429f86b132e6d40
dashboard link: https://syzkaller.appspot.com/bug?extid=3ae6be33a50b5aae4dab
compiler:       clang version 15.0.0 (https://github.com/llvm/llvm-project.git 610139d2d9ce6746b3c617fb3e2f7886272d26ff), GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: i386

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a8bf743ab4c3/disk-a472f15b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7248eae68bc7/vmlinux-a472f15b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0e33e55592a5/bzImage-a472f15b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3ae6be33a50b5aae4dab@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 64
=====================================================
BUG: KMSAN: uninit-value in hfs_revalidate_dentry+0x17f/0x3e0 fs/hfs/sysdep.c:30
 hfs_revalidate_dentry+0x17f/0x3e0 fs/hfs/sysdep.c:30
 d_revalidate fs/namei.c:856 [inline]
 lookup_open fs/namei.c:3345 [inline]
 open_last_lookups fs/namei.c:3481 [inline]
 path_openat+0x115a/0x5600 fs/namei.c:3710
 do_filp_open+0x249/0x660 fs/namei.c:3740
 do_sys_openat2+0x1f0/0x910 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_compat_sys_openat fs/open.c:1386 [inline]
 __se_compat_sys_openat fs/open.c:1384 [inline]
 __ia32_compat_sys_openat+0x2a7/0x330 fs/open.c:1384
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

Uninit was created at:
 __alloc_pages+0x9f1/0xe80 mm/page_alloc.c:5578
 alloc_pages+0xaae/0xd80 mm/mempolicy.c:2285
 alloc_slab_page mm/slub.c:1794 [inline]
 allocate_slab+0x1b5/0x1010 mm/slub.c:1939
 new_slab mm/slub.c:1992 [inline]
 ___slab_alloc+0x10c3/0x2d60 mm/slub.c:3180
 __slab_alloc mm/slub.c:3279 [inline]
 slab_alloc_node mm/slub.c:3364 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc_lru+0x6f3/0xb30 mm/slub.c:3429
 alloc_inode_sb include/linux/fs.h:3117 [inline]
 hfs_alloc_inode+0x56/0xc0 fs/hfs/super.c:165
 alloc_inode+0x83/0x440 fs/inode.c:259
 iget_locked+0x2a1/0xe20 fs/inode.c:1286
 hfs_btree_open+0x162/0x1ab0 fs/hfs/btree.c:38
 hfs_mdb_get+0x207d/0x29b0 fs/hfs/mdb.c:199
 hfs_fill_super+0x1d13/0x2400 fs/hfs/super.c:406
 mount_bdev+0x508/0x840 fs/super.c:1401
 hfs_mount+0x49/0x60 fs/hfs/super.c:456
 legacy_get_tree+0x10c/0x280 fs/fs_context.c:610
 vfs_get_tree+0xa1/0x500 fs/super.c:1531
 do_new_mount+0x694/0x1580 fs/namespace.c:3040
 path_mount+0x71a/0x1eb0 fs/namespace.c:3370
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount+0x734/0x840 fs/namespace.c:3568
 __ia32_sys_mount+0xdf/0x140 fs/namespace.c:3568
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

CPU: 0 PID: 4234 Comm: syz-executor.0 Not tainted 6.1.0-rc6-syzkaller-63555-ga472f15b3d1e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
=====================================================


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