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Date: Sun, 03 Mar 2024 07:51:14 -0800
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Subject: Re: [syzbot] [hfs?] 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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syzbot has found a reproducer for the following issue on:

HEAD commit:    04b8076df253 Merge tag 'firewire-fixes-6.8-rc7' of git://g..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=175aa96a180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=80c7a82a572c0de3
dashboard link: https://syzkaller.appspot.com/bug?extid=c6d8e1bffb0970780d5c
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=173516ee180000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12fd7bba180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a4610b1ff2a7/disk-04b8076d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/991e9d902d39/vmlinux-04b8076d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a5b8e8e98121/bzImage-04b8076d.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/111a30273774/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c6d8e1bffb0970780d5c@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 1024
=====================================================
BUG: KMSAN: uninit-value in hfsplus_attr_bin_cmp_key+0xf1/0x190 fs/hfsplus/attributes.c:42
 hfsplus_attr_bin_cmp_key+0xf1/0x190 fs/hfsplus/attributes.c:42
 hfs_find_rec_by_key+0xb0/0x240 fs/hfsplus/bfind.c:100
 __hfsplus_brec_find+0x26b/0x7b0 fs/hfsplus/bfind.c:135
 hfsplus_brec_find+0x445/0x970 fs/hfsplus/bfind.c:195
 hfsplus_find_attr+0x30c/0x390
 hfsplus_attr_exists+0x1c6/0x260 fs/hfsplus/attributes.c:182
 __hfsplus_setxattr+0x510/0x3580 fs/hfsplus/xattr.c:336
 hfsplus_setxattr+0x129/0x1e0 fs/hfsplus/xattr.c:434
 hfsplus_trusted_setxattr+0x55/0x70 fs/hfsplus/xattr_trusted.c:30
 __vfs_setxattr+0x7aa/0x8b0 fs/xattr.c:201
 __vfs_setxattr_noperm+0x24f/0xa30 fs/xattr.c:235
 __vfs_setxattr_locked+0x441/0x480 fs/xattr.c:296
 vfs_setxattr+0x294/0x650 fs/xattr.c:322
 do_setxattr fs/xattr.c:630 [inline]
 setxattr+0x45f/0x540 fs/xattr.c:653
 path_setxattr+0x1f5/0x3c0 fs/xattr.c:672
 __do_sys_setxattr fs/xattr.c:688 [inline]
 __se_sys_setxattr fs/xattr.c:684 [inline]
 __x64_sys_setxattr+0xf7/0x180 fs/xattr.c:684
 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]
 hfsplus_find_init+0x91/0x250 fs/hfsplus/bfind.c:21
 hfsplus_attr_exists+0xde/0x260 fs/hfsplus/attributes.c:178
 __hfsplus_setxattr+0x510/0x3580 fs/hfsplus/xattr.c:336
 hfsplus_setxattr+0x129/0x1e0 fs/hfsplus/xattr.c:434
 hfsplus_trusted_setxattr+0x55/0x70 fs/hfsplus/xattr_trusted.c:30
 __vfs_setxattr+0x7aa/0x8b0 fs/xattr.c:201
 __vfs_setxattr_noperm+0x24f/0xa30 fs/xattr.c:235
 __vfs_setxattr_locked+0x441/0x480 fs/xattr.c:296
 vfs_setxattr+0x294/0x650 fs/xattr.c:322
 do_setxattr fs/xattr.c:630 [inline]
 setxattr+0x45f/0x540 fs/xattr.c:653
 path_setxattr+0x1f5/0x3c0 fs/xattr.c:672
 __do_sys_setxattr fs/xattr.c:688 [inline]
 __se_sys_setxattr fs/xattr.c:684 [inline]
 __x64_sys_setxattr+0xf7/0x180 fs/xattr.c:684
 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: 0 PID: 5013 Comm: syz-executor247 Not tainted 6.8.0-rc6-syzkaller-00250-g04b8076df253 #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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