KASAN: use-after-free Read in should_fail

Status: closed as dup on 2018/05/04 13:17
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+7f7b8d424eb621469f0a@syzkaller.appspotmail.com
First crash: 3015d, last: 3013d
▶ ▼ Duplicate of
Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported
KASAN: use-after-free Read in fuse_kill_sb_blk fuse 19 4 3000d 3019d
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
KASAN: use-after-free Read in should_fail 1 (2) 2018/05/04 13:17

Sample crash report:
R10: 0000000000000000 R11: 0000000000000206 R12: ffffffffffffffff
R13: 0000000000000003 R14: 0000000000001380 R15: 00007fff62b2dd98
CPU: 1 PID: 4530 Comm: syz-executor216 Not tainted 4.17.0-rc3+ #35
==================================================================
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
BUG: KASAN: use-after-free in __lock_acquire+0x3888/0x5140 kernel/locking/lockdep.c:3310
Read of size 8 at addr ffff8801d8bc2bc8 by task syz-executor216/4528
Call Trace:

 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 fail_dump lib/fault-inject.c:51 [inline]
 should_fail.cold.4+0xa/0x1a lib/fault-inject.c:149
 __should_failslab+0x124/0x180 mm/failslab.c:32
 should_failslab+0x9/0x14 mm/slab_common.c:1522
 slab_pre_alloc_hook mm/slab.h:423 [inline]
 slab_alloc mm/slab.c:3378 [inline]
 kmem_cache_alloc+0x2af/0x760 mm/slab.c:3552
 __fuse_request_alloc+0x27/0xf0 fs/fuse/dev.c:58
 fuse_request_alloc+0x18/0x20 fs/fuse/dev.c:86
 fuse_fill_super+0x124e/0x1e20 fs/fuse/inode.c:1137
 mount_nodev+0x6b/0x110 fs/super.c:1210
 fuse_mount+0x2c/0x40 fs/fuse/inode.c:1192
 mount_fs+0xae/0x328 fs/super.c:1267
 vfs_kern_mount.part.34+0xd4/0x4d0 fs/namespace.c:1037
 vfs_kern_mount fs/namespace.c:1027 [inline]
 do_new_mount fs/namespace.c:2518 [inline]
 do_mount+0x564/0x3070 fs/namespace.c:2848
 ksys_mount+0x12d/0x140 fs/namespace.c:3064
 __do_sys_mount fs/namespace.c:3078 [inline]
 __se_sys_mount fs/namespace.c:3075 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3075
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x442689
RSP: 002b:00007fff62b2dc48 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442689
RDX: 00000000004a451e RSI: 0000000020000180 RDI: 00000000004ba505
RBP: 00007fff62b2e500 R08: 00007fff62b2e500 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: ffffffffffffffff
R13: 0000000000000003 R14: 0000000000001380 R15: 00007fff62b2dd98
CPU: 0 PID: 4528 Comm: syz-executor216 Not tainted 4.17.0-rc3+ #35
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+0x1b9/0x294 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 __lock_acquire+0x3888/0x5140 kernel/locking/lockdep.c:3310
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 down_write+0x87/0x120 kernel/locking/rwsem.c:70
 fuse_kill_sb_anon+0x50/0xb0 fs/fuse/inode.c:1200
 deactivate_locked_super+0x97/0x100 fs/super.c:316
 mount_nodev+0xfa/0x110 fs/super.c:1212
 fuse_mount+0x2c/0x40 fs/fuse/inode.c:1192
 mount_fs+0xae/0x328 fs/super.c:1267
 vfs_kern_mount.part.34+0xd4/0x4d0 fs/namespace.c:1037
 vfs_kern_mount fs/namespace.c:1027 [inline]
 do_new_mount fs/namespace.c:2518 [inline]
 do_mount+0x564/0x3070 fs/namespace.c:2848
 ksys_mount+0x12d/0x140 fs/namespace.c:3064
 __do_sys_mount fs/namespace.c:3078 [inline]
 __se_sys_mount fs/namespace.c:3075 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3075
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x442689
RSP: 002b:00007fff62b2dc48 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442689
RDX: 00000000004a451e RSI: 0000000020000180 RDI: 00000000004ba505
RBP: 00007fff62b2e500 R08: 00007fff62b2e500 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: ffffffffffffffff
R13: 0000000000000003 R14: 0000000000001380 R15: 00007fff62b2dd98

CPU: 1 PID: 4532 Comm: syz-executor216 Not tainted 4.17.0-rc3+ #35
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Allocated by task 4528:
Call Trace:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620
 kmalloc include/linux/slab.h:512 [inline]
 fuse_fill_super+0xc92/0x1e20 fs/fuse/inode.c:1096
 mount_nodev+0x6b/0x110 fs/super.c:1210
 fuse_mount+0x2c/0x40 fs/fuse/inode.c:1192
 mount_fs+0xae/0x328 fs/super.c:1267
 fail_dump lib/fault-inject.c:51 [inline]
 should_fail.cold.4+0xa/0x1a lib/fault-inject.c:149
 vfs_kern_mount.part.34+0xd4/0x4d0 fs/namespace.c:1037
 vfs_kern_mount fs/namespace.c:1027 [inline]
 do_new_mount fs/namespace.c:2518 [inline]
 do_mount+0x564/0x3070 fs/namespace.c:2848
 ksys_mount+0x12d/0x140 fs/namespace.c:3064
 __do_sys_mount fs/namespace.c:3078 [inline]
 __se_sys_mount fs/namespace.c:3075 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3075
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 4525:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xd9/0x260 mm/slab.c:3813
 __rcu_reclaim kernel/rcu/rcu.h:173 [inline]
 rcu_do_batch kernel/rcu/tree.c:2675 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2930 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2897 [inline]
 rcu_process_callbacks+0xa69/0x15f0 kernel/rcu/tree.c:2914
 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285

The buggy address belongs to the object at ffff8801d8bc2900
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 712 bytes inside of
 1024-byte region [ffff8801d8bc2900, ffff8801d8bc2d00)
 __should_failslab+0x124/0x180 mm/failslab.c:32
The buggy address belongs to the page:
page:ffffea000762f080 count:1 mapcount:0 mapping:ffff8801d8bc2000 index:0x0
 should_failslab+0x9/0x14 mm/slab_common.c:1522
 compound_mapcount: 0
 slab_pre_alloc_hook mm/slab.h:423 [inline]
 slab_alloc mm/slab.c:3378 [inline]
 __do_kmalloc mm/slab.c:3716 [inline]
 __kmalloc_track_caller+0x2c4/0x760 mm/slab.c:3733
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff8801d8bc2000 0000000000000000 0000000100000007
raw: ffffea000762d0a0 ffffea000741b120 ffff8801da800ac0 0000000000000000
page dumped because: kasan: bad access detected

 kstrdup+0x39/0x70 mm/util.c:56
Memory state around the buggy address:
 ffff8801d8bc2a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 fs_set_subtype fs/namespace.c:2443 [inline]
 do_new_mount fs/namespace.c:2521 [inline]
 do_mount+0x25e7/0x3070 fs/namespace.c:2848
 ffff8801d8bc2b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801d8bc2b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff8801d8bc2c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d8bc2c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/05/06 06:45 upstream ee946c36be21 78b251cb .config console log report syz C ci-upstream-kasan-gce-root
2018/05/04 11:18 upstream 150426981426 9ce14f4b .config console log report syz C ci-upstream-kasan-gce-root
* Struck through repros no longer work on HEAD.