syzbot


KASAN: use-after-free Read in corrupted

Status: fixed on 2018/07/09 18:05
Reported-by: syzbot+3417712847e7219a60ee@syzkaller.appspotmail.com
Fix commit: 543b8f8662fe fuse: don't keep dead fuse_conn at fuse_fill_super().
First crash: 1671d, last: 1668d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 KASAN: use-after-free Read in corrupted syz error 1 283d 754d 0/1 upstream: reported syz repro on 2020/11/15 10:58
android-414 KASAN: use-after-free Read in corrupted C 2 1222d 1223d 0/1 public: reported C repro on 2019/08/03 12:36
upstream KASAN: use-after-free Read in corrupted (3) syz done 1 1262d 1262d 13/24 fixed on 2019/08/27 17:15
upstream KASAN: use-after-free Read in corrupted (2) syz 1 1324d 1324d 0/24 closed as invalid on 2019/04/25 11:05
upstream KASAN: use-after-free Read in corrupted (4) C done error 9 155d 849d 0/24 upstream: reported C repro on 2020/08/11 12:47

Sample crash report:
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
CPU: 0 PID: 4564 Comm: syz-executor214 Not tainted 4.17.0-rc4+ #44
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Call Trace:
BUG: KASAN: use-after-free in __lock_acquire+0x3888/0x5140 kernel/locking/lockdep.c:3310
Read of size 8 at addr ffff8801d8d69088 by task syz-executor214/4551
 __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
 __d_alloc+0xc0/0xd30 fs/dcache.c:1638
 d_alloc_anon fs/dcache.c:1742 [inline]
 d_make_root+0x42/0x90 fs/dcache.c:1934
 fuse_fill_super+0x120e/0x1e20 fs/fuse/inode.c:1131
 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: 0033:0x447cb9
RSP: 002b:00007f7a75bca918 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000447cb9
RDX: 00000000004b08d6 RSI: 0000000020000340 RDI: 00000000004c7485
RBP: 000000000000a001 R08: 00007f7a75bca930 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
CPU: 1 PID: 4551 Comm: syz-executor214 Not tainted 4.17.0-rc4+ #44
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
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
 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
 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: 0033:0x447cb9
RSP: 002b:00007f7a75bca918 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000447cb9
RDX: 00000000004b08d6 RSI: 0000000020000340 RDI: 00000000004c7485
RBP: 000000000000a001 R08: 00007f7a75bca930 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

CPU: 0 PID: 4580 Comm: syz-executor214 Not tainted 4.17.0-rc4+ #44
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Allocated by task 4551:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
Call Trace:
 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
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 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
 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
 fail_dump lib/fault-inject.c:51 [inline]
 should_fail.cold.4+0xa/0x1a lib/fault-inject.c:149
 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 8:
 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 ffff8801d8d68dc0
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 712 bytes inside of
 1024-byte region [ffff8801d8d68dc0, ffff8801d8d691c0)
The buggy address belongs to the page:
page:ffffea0007635a00 count:1 mapcount:0 mapping:ffff8801d8d68040 index:0x0
 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
 __should_failslab+0x124/0x180 mm/failslab.c:32
raw: 02fffc0000008100 ffff8801d8d68040 0000000000000000 0000000100000007
 should_failslab+0x9/0x14 mm/slab_common.c:1522
raw: ffffea00076407a0 ffffea00076335a0 ffff8801da800ac0 0000000000000000
 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
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d8d68f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d8d69000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801d8d69080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 __d_alloc+0xc0/0xd30 fs/dcache.c:1638
                      ^
 ffff8801d8d69100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d8d69180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2018/05/13 06:51 upstream 427fbe89261d e726f42b .config log report syz C
ci-upstream-kasan-gce-root 2018/05/16 00:19 upstream eeba2dfa6a0d 68ce85f1 .config log report syz
* Struck through repros no longer work on HEAD.