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Date:   Mon, 28 Nov 2022 02:04:38 -0800
Message-ID: <000000000000d60fa905ee84ff8d@google.com>
Subject: [syzbot] KMSAN: uninit-value in hfsplus_attr_bin_cmp_key
From:   syzbot <syzbot+c6d8e1bffb0970780d5c@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=14886381880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1429f86b132e6d40
dashboard link: https://syzkaller.appspot.com/bug?extid=c6d8e1bffb0970780d5c
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+c6d8e1bffb0970780d5c@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in hfsplus_attr_bin_cmp_key+0xed/0x180 fs/hfsplus/attributes.c:42
 hfsplus_attr_bin_cmp_key+0xed/0x180 fs/hfsplus/attributes.c:42
 hfs_find_rec_by_key+0xac/0x240 fs/hfsplus/bfind.c:100
 __hfsplus_brec_find+0x27a/0x7d0 fs/hfsplus/bfind.c:135
 hfsplus_brec_find+0x46a/0x9d0 fs/hfsplus/bfind.c:195
 hfsplus_find_attr+0x308/0x380
 __hfsplus_getxattr+0x380/0xe50 fs/hfsplus/xattr.c:522
 hfsplus_getxattr+0x11f/0x1d0 fs/hfsplus/xattr.c:590
 hfsplus_security_getxattr+0x4f/0x60 fs/hfsplus/xattr_security.c:20
 __vfs_getxattr+0x699/0x6f0 fs/xattr.c:407
 cap_inode_need_killpriv+0x52/0xb0 security/commoncap.c:301
 security_inode_need_killpriv+0x8f/0x140 security/security.c:1422
 dentry_needs_remove_privs+0x1b4/0x3f0 fs/inode.c:1995
 do_truncate+0x11f/0x2d0 fs/open.c:57
 handle_truncate fs/namei.c:3216 [inline]
 do_open fs/namei.c:3561 [inline]
 path_openat+0x4cf7/0x5600 fs/namei.c:3713
 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_sys_creat fs/open.c:1402 [inline]
 __se_sys_creat fs/open.c:1396 [inline]
 __ia32_sys_creat+0xed/0x160 fs/open.c:1396
 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:
 slab_post_alloc_hook mm/slab.h:742 [inline]
 slab_alloc_node mm/slub.c:3398 [inline]
 __kmem_cache_alloc_node+0x6ee/0xc90 mm/slub.c:3437
 __do_kmalloc_node mm/slab_common.c:954 [inline]
 __kmalloc+0x11d/0x3c0 mm/slab_common.c:968
 kmalloc include/linux/slab.h:558 [inline]
 hfsplus_find_init+0x8d/0x250 fs/hfsplus/bfind.c:21
 __hfsplus_getxattr+0x2d1/0xe50 fs/hfsplus/xattr.c:516
 hfsplus_getxattr+0x11f/0x1d0 fs/hfsplus/xattr.c:590
 hfsplus_security_getxattr+0x4f/0x60 fs/hfsplus/xattr_security.c:20
 __vfs_getxattr+0x699/0x6f0 fs/xattr.c:407
 cap_inode_need_killpriv+0x52/0xb0 security/commoncap.c:301
 security_inode_need_killpriv+0x8f/0x140 security/security.c:1422
 dentry_needs_remove_privs+0x1b4/0x3f0 fs/inode.c:1995
 do_truncate+0x11f/0x2d0 fs/open.c:57
 handle_truncate fs/namei.c:3216 [inline]
 do_open fs/namei.c:3561 [inline]
 path_openat+0x4cf7/0x5600 fs/namei.c:3713
 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_sys_creat fs/open.c:1402 [inline]
 __se_sys_creat fs/open.c:1396 [inline]
 __ia32_sys_creat+0xed/0x160 fs/open.c:1396
 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: 3846 Comm: syz-executor.3 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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