KASAN: slab-out-of-bounds Read in ntfs_attr_find

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: cbfa1702 Linux 4.14.198
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=121fa8ad900000
kernel config: https://syzkaller.appspot.com/x/.config?x=3990958d85b55e59
dashboard link: https://syzkaller.appspot.com/bug?extid=bc53b9b58b7531ec0268
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16395cd3900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14d5d23d900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bc53b9...@syzkaller.appspotmail.com

audit: type=1400 audit(1600863089.241:8): avc: denied { execmem } for pid=6376 comm="syz-executor065" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1
IPVS: ftp: loaded support on port[0] = 21
ntfs: (device loop0): is_boot_sector_ntfs(): Invalid end of sector marker.
==================================================================
BUG: KASAN: slab-out-of-bounds in ntfs_attr_find+0x8df/0xa10 fs/ntfs/attrib.c:613
Read of size 4 at addr ffff8880971a2480 by task syz-executor065/6377

CPU: 0 PID: 6377 Comm: syz-executor065 Not tainted 4.14.198-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x1b2/0x283 lib/dump_stack.c:58
print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351
kasan_report mm/kasan/report.c:409 [inline]
__asan_report_load_n_noabort+0x6b/0x80 mm/kasan/report.c:440
ntfs_attr_find+0x8df/0xa10 fs/ntfs/attrib.c:613
ntfs_attr_lookup+0xeca/0x1f30 fs/ntfs/attrib.c:1203
ntfs_read_inode_mount+0x6b4/0x1fb0 fs/ntfs/inode.c:1867
ntfs_fill_super+0x9a6/0x7170 fs/ntfs/super.c:2871
mount_bdev+0x2b3/0x360 fs/super.c:1134
mount_fs+0x92/0x2a0 fs/super.c:1237
vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
vfs_kern_mount fs/namespace.c:1036 [inline]
do_new_mount fs/namespace.c:2549 [inline]
do_mount+0xe53/0x2a00 fs/namespace.c:2879
SYSC_mount fs/namespace.c:3095 [inline]
SyS_mount+0xa8/0x120 fs/namespace.c:3072
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x447cda
RSP: 002b:00007fff14bcd6b8 EFLAGS: 00000287 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fff14bcd710 RCX: 0000000000447cda
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fff14bcd6d0
RBP: 0000000000000004 R08: 00007fff14bcd710 R09: 00007fff14bcd700
R10: 0000000000000000 R11: 0000000000000287 R12: 0000000000000003
R13: 00007fff14bcd6d0 R14: 0000000000000000 R15: 0000000020000780

Allocated by task 6370:
save_stack mm/kasan/kasan.c:447 [inline]
set_track mm/kasan/kasan.c:459 [inline]
kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
kmem_cache_alloc+0x124/0x3c0 mm/slab.c:3552
getname_flags+0xc8/0x550 fs/namei.c:138
do_sys_open+0x1ce/0x410 fs/open.c:1075
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb

Freed by task 6370:
save_stack mm/kasan/kasan.c:447 [inline]
set_track mm/kasan/kasan.c:459 [inline]
kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
__cache_free mm/slab.c:3496 [inline]
kmem_cache_free+0x7c/0x2b0 mm/slab.c:3758
putname+0xcd/0x110 fs/namei.c:259
do_sys_open+0x203/0x410 fs/open.c:1090
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb

The buggy address belongs to the object at ffff8880971a2cc0
which belongs to the cache names_cache of size 4096
The buggy address is located 2112 bytes to the left of
4096-byte region [ffff8880971a2cc0, ffff8880971a3cc0)
The buggy address belongs to the page:
page:ffffea00025c6880 count:1 mapcount:0 mapping:ffff8880971a2cc0 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffff8880971a2cc0 0000000000000000 0000000100000001
raw: ffffea00025c3320 ffffea00025c2120 ffff8880aa58ccc0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff8880971a2380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880971a2400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880971a2480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff8880971a2500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880971a2580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
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syzbot can test patches for this issue, for details see:
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[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 10ad6cfd Linux 4.19.148
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=10d99dd3900000
kernel config: https://syzkaller.appspot.com/x/.config?x=ef9a7978d84ee42b
dashboard link: https://syzkaller.appspot.com/bug?extid=c77e7a332f782109bef2

compiler: gcc (GCC) 10.1.0-syz 20200507

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by: syzbot+c77e7a...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-out-of-bounds in ntfs_attr_find+0xa42/0xb70 fs/ntfs/attrib.c:613
Read of size 4 at addr ffff8880a897843f by task syz-executor.1/676

CPU: 0 PID: 676 Comm: syz-executor.1 Not tainted 4.19.148-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:

__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x22c/0x33e lib/dump_stack.c:118
print_address_description.cold+0x56/0x25c mm/kasan/report.c:256
kasan_report_error.cold+0x66/0xb9 mm/kasan/report.c:354
kasan_report mm/kasan/report.c:412 [inline]
__asan_report_load_n_noabort+0x8b/0xa0 mm/kasan/report.c:443
ntfs_attr_find+0xa42/0xb70 fs/ntfs/attrib.c:613
ntfs_attr_lookup+0x1087/0x2060 fs/ntfs/attrib.c:1203
ntfs_read_inode_mount+0x7e4/0x23b0 fs/ntfs/inode.c:1858
ntfs_fill_super+0x1761/0x89d2 fs/ntfs/super.c:2871
mount_bdev+0x2fc/0x3b0 fs/super.c:1158
mount_fs+0xa3/0x318 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:2469 [inline]
do_mount+0x51c/0x2f10 fs/namespace.c:2799
ksys_mount+0xcf/0x130 fs/namespace.c:3015
__do_sys_mount fs/namespace.c:3029 [inline]
__se_sys_mount fs/namespace.c:3026 [inline]
__x64_sys_mount+0xba/0x150 fs/namespace.c:3026
do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x460bca
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 dd 87 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 ba 87 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007fea3b068a88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fea3b068b20 RCX: 0000000000460bca
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fea3b068ae0
RBP: 00007fea3b068ae0 R08: 00007fea3b068b20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020086e00

Allocated by task 447:
kmem_cache_alloc+0x126/0x4a0 mm/slab.c:3559
getname_flags+0xce/0x590 fs/namei.c:140
getname fs/namei.c:211 [inline]
user_path_create fs/namei.c:3696 [inline]
do_symlinkat+0xce/0x2c0 fs/namei.c:4149
do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 447:
__cache_free mm/slab.c:3503 [inline]
kmem_cache_free+0x7f/0x2b0 mm/slab.c:3765
putname+0xe1/0x130 fs/namei.c:261
filename_create+0x22e/0x490 fs/namei.c:3661
user_path_create fs/namei.c:3696 [inline]
do_symlinkat+0xe1/0x2c0 fs/namei.c:4149
do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880a8978a80

which belongs to the cache names_cache of size 4096

The buggy address is located 1601 bytes to the left of
4096-byte region [ffff8880a8978a80, ffff8880a8979a80)

The buggy address belongs to the page:

page:ffffea0002a25e00 count:1 mapcount:0 mapping:ffff88821bc44b00 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffffea000253d108 ffffea00010b6b08 ffff88821bc44b00
raw: 0000000000000000 ffff8880a8978a80 0000000100000001 0000000000000000

page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff8880a8978300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880a8978380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a8978400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff8880a8978480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880a8978500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
__ntfs_error: 105 callbacks suppressed
ntfs: (device loop4): load_system_files(): Failed to load $Bitmap.
(syz-executor.5,686,1):ocfs2_parse_options:1513 ERROR: Invalid heartbeat mount options
(syz-executor.5,686,1):ocfs2_fill_super:1225 ERROR: status = -22
ntfs: (device loop4): ntfs_fill_super(): Failed to load system files.
ntfs: (device loop0): load_system_files(): Failed to load $Bitmap.
ntfs: (device loop0): ntfs_fill_super(): Failed to load system files.
(syz-executor.5,686,1):ocfs2_parse_options:1513 ERROR: Invalid heartbeat mount options
(syz-executor.5,686,1):ocfs2_fill_super:1225 ERROR: status = -22
ntfs: (device loop2): parse_ntfs_boot_sector(): Cannot handle 64-bit clusters. Sorry.
ntfs: (device loop2): ntfs_fill_super(): Unsupported NTFS filesystem.
ntfs: (device loop3): parse_ntfs_boot_sector(): Cannot handle 64-bit clusters. Sorry.
ntfs: (device loop3): ntfs_fill_super(): Unsupported NTFS filesystem.

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: b09c3451 Linux 4.19.149
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13afcdeb900000
kernel config: https://syzkaller.appspot.com/x/.config?x=d7c6dfb55644e8fd

dashboard link: https://syzkaller.appspot.com/bug?extid=c77e7a332f782109bef2
compiler: gcc (GCC) 10.1.0-syz 20200507

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1011ebdb900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1078aab7900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c77e7a...@syzkaller.appspotmail.com

audit: type=1400 audit(1601770290.364:8): avc: denied { execmem } for pid=6471 comm="syz-executor353" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1

ntfs: (device loop0): is_boot_sector_ntfs(): Invalid end of sector marker.

==================================================================
BUG: KASAN: slab-out-of-bounds in ntfs_attr_find+0xa42/0xb70 fs/ntfs/attrib.c:613

Read of size 4 at addr ffff8880a539403f by task syz-executor353/6471

CPU: 0 PID: 6471 Comm: syz-executor353 Not tainted 4.19.149-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x22c/0x33e lib/dump_stack.c:118
print_address_description.cold+0x56/0x25c mm/kasan/report.c:256
kasan_report_error.cold+0x66/0xb9 mm/kasan/report.c:354
kasan_report mm/kasan/report.c:412 [inline]
__asan_report_load_n_noabort+0x8b/0xa0 mm/kasan/report.c:443
ntfs_attr_find+0xa42/0xb70 fs/ntfs/attrib.c:613
ntfs_attr_lookup+0x1087/0x2060 fs/ntfs/attrib.c:1203
ntfs_read_inode_mount+0x7e4/0x23b0 fs/ntfs/inode.c:1858
ntfs_fill_super+0x1761/0x89d2 fs/ntfs/super.c:2871
mount_bdev+0x2fc/0x3b0 fs/super.c:1158
mount_fs+0xa3/0x318 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:2469 [inline]
do_mount+0x51c/0x2f10 fs/namespace.c:2799
ksys_mount+0xcf/0x130 fs/namespace.c:3015
__do_sys_mount fs/namespace.c:3029 [inline]
__se_sys_mount fs/namespace.c:3026 [inline]
__x64_sys_mount+0xba/0x150 fs/namespace.c:3026
do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

RIP: 0033:0x44c1fa
Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 fd ad fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 da ad fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007ffc1695edb8 EFLAGS: 00000287 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffc1695ee10 RCX: 000000000044c1fa
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffc1695edd0
RBP: 00007ffc1695edd0 R08: 00007ffc1695ee10 R09: 00007ffc00000015
R10: 0000000000000000 R11: 0000000000000287 R12: 000000000000025d
R13: 0000000000000004 R14: 0000000000000003 R15: 0000000000000003

Allocated by task 6471:
kmem_cache_alloc_trace+0x12f/0x4b0 mm/slab.c:3625
kmalloc include/linux/slab.h:515 [inline]
copy_mount_options+0x59/0x370 fs/namespace.c:2678
ksys_mount+0x9b/0x130 fs/namespace.c:3010

__do_sys_mount fs/namespace.c:3029 [inline]
__se_sys_mount fs/namespace.c:3026 [inline]
__x64_sys_mount+0xba/0x150 fs/namespace.c:3026
do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8880a5394e40
which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 3585 bytes to the left of
4096-byte region [ffff8880a5394e40, ffff8880a5395e40)

The buggy address belongs to the page:

page:ffffea000294e500 count:1 mapcount:0 mapping:ffff88812c3f6dc0 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffffea0002935608 ffffea0002920408 ffff88812c3f6dc0
raw: 0000000000000000 ffff8880a5394e40 0000000100000001 0000000000000000

page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff8880a5393f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff8880a5393f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880a5394000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff8880a5394080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880a5394100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

[syzbot]

syzbot suspects this issue was fixed by commit:

commit d2918cca649f7457018f2c94176a8302e7a9f311
Author: Rustam Kovhaev <rkov...@gmail.com>
Date: Tue Oct 13 23:48:17 2020 +0000

ntfs: add check for mft record size in superblock

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=127c99e1500000
start commit: cbfa1702 Linux 4.14.198
git tree: linux-4.14.y

kernel config: https://syzkaller.appspot.com/x/.config?x=3990958d85b55e59
dashboard link: https://syzkaller.appspot.com/bug?extid=bc53b9b58b7531ec0268

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=128a270c500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11bbe3f0500000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: ntfs: add check for mft record size in superblock

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[syzbot]

syzbot suspects this issue was fixed by commit:

commit dff5d774119537355b01e5b503d9468228d65044

Author: Rustam Kovhaev <rkov...@gmail.com>
Date: Tue Oct 13 23:48:17 2020 +0000

ntfs: add check for mft record size in superblock

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15864d83500000
start commit: ad326970 Linux 4.19.152
git tree: linux-4.19.y
kernel config: https://syzkaller.appspot.com/x/.config?x=19e1d59b1459bb9a
dashboard link: https://syzkaller.appspot.com/bug?extid=c77e7a332f782109bef2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15591930500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1461b1cf900000