syzbot


KASAN: use-after-free Read in ntfs_collate_names

Status: upstream: reported C repro on 2023/02/26 10:39
Reported-by: syzbot+028a20987560ec9a96dd@syzkaller.appspotmail.com
First crash: 673d, last: 673d

Sample crash report:
IPv6: ADDRCONF(NETDEV_CHANGE): macvtap0: link becomes ready
batman_adv: batadv0: Interface activated: batadv_slave_1
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
ntfs: volume version 3.1.
==================================================================
BUG: KASAN: use-after-free in ntfs_collate_names+0x329/0x380 fs/ntfs/unistr.c:110
Read of size 2 at addr ffff888090a7c92f by task syz-executor120/8112

CPU: 0 PID: 8112 Comm: syz-executor120 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load2_noabort+0x88/0x90 mm/kasan/report.c:431
 ntfs_collate_names+0x329/0x380 fs/ntfs/unistr.c:110
 ntfs_attr_find+0x7e5/0xb10 fs/ntfs/attrib.c:633
 ntfs_attr_lookup+0x1020/0x1f90 fs/ntfs/attrib.c:1203
 ntfs_read_locked_inode+0x1cbf/0x56e0 fs/ntfs/inode.c:793
 ntfs_iget+0x12d/0x180 fs/ntfs/inode.c:190
 load_system_files fs/ntfs/super.c:1988 [inline]
 ntfs_fill_super+0x5851/0x7e10 fs/ntfs/super.c:2908
 mount_bdev+0x2fc/0x3b0 fs/super.c:1158
 mount_fs+0xa3/0x310 fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2492 [inline]
 do_mount+0x115c/0x2f50 fs/namespace.c:2822
 ksys_mount+0xcf/0x130 fs/namespace.c:3038
 __do_sys_mount fs/namespace.c:3052 [inline]
 __se_sys_mount fs/namespace.c:3049 [inline]
 __x64_sys_mount+0xba/0x150 fs/namespace.c:3049
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f434928c49a
Code: 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 08 01 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe11c0ae68 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f434928c49a
RDX: 0000000020000040 RSI: 000000002001ee80 RDI: 00007ffe11c0ae80
RBP: 00007ffe11c0ae80 R08: 00007ffe11c0aec0 R09: 000000000001ee5a
R10: 0000000000a00c9a R11: 0000000000000286 R12: 0000000000000004
R13: 00005555559e12b8 R14: 0000000000a00c9a R15: 00007ffe11c0aec0

The buggy address belongs to the page:
page:ffffea0002429f00 count:0 mapcount:0 mapping:0000000000000000 index:0x1
flags: 0xfff00000000000()
raw: 00fff00000000000 ffffea000242cc08 ffffea000242d5c8 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888090a7c800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888090a7c880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888090a7c900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                  ^
 ffff888090a7c980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888090a7ca00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/02/26 10:58 linux-4.19.y 3f8a27f9e27b ee50e71c .config console log report syz C [disk image] [vmlinux] [mounted in repro] ci2-linux-4-19 KASAN: use-after-free Read in ntfs_collate_names
2023/02/26 10:38 linux-4.19.y 3f8a27f9e27b ee50e71c .config console log report info [disk image] [vmlinux] ci2-linux-4-19 KASAN: use-after-free Read in ntfs_collate_names
* Struck through repros no longer work on HEAD.