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WARNING: held lock freed in nr_release

Status: fixed on 2019/08/27 17:15
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+a34e5f3d0300163f0c87@syzkaller.appspotmail.com
Fix commit: 4638faac0327 netrom: hold sock when setting skb->destructor
First crash: 1910d, last: 1888d
Cause bisection: introduced by (bisect log) :
commit c8c8218ec5af5d2598381883acbefbf604e56b5e
Author: Cong Wang <xiyou.wangcong@gmail.com>
Date: Thu Jun 27 21:30:58 2019 +0000

  netrom: fix a memory leak in nr_rx_frame()

Crash: WARNING: held lock freed in nr_release (log)
Repro: syz .config
  
▶ ▼ Discussions (9)
Title Replies (including bot) Last reply
[PATCH 4.9 000/223] 4.9.187-stable review 231 (231) 2019/08/28 03:02
[PATCH 4.4 000/158] 4.4.187-stable review 166 (166) 2019/08/03 15:57
[PATCH 4.14 000/293] 4.14.135-stable review 302 (302) 2019/07/31 09:35
[PATCH 5.2 00/66] 5.2.4-stable review 78 (78) 2019/07/29 15:12
[PATCH 5.1 00/62] 5.1.21-stable review 68 (68) 2019/07/29 09:02
[PATCH 4.19 00/50] 4.19.62-stable review 56 (56) 2019/07/29 09:02
[Patch net] netrom: hold sock when setting skb->destructor 2 (2) 2019/07/24 22:49
Reminder: 13 open syzbot bugs in "net/netrom" subsystem 2 (2) 2019/07/24 17:02
WARNING: held lock freed in nr_release 0 (2) 2019/07/17 10:05
▶ ▼ Last patch testing requests (2)
Created Duration User Patch Repo Result
2019/07/22 19:17 20m xiyou.wangcong@gmail.com https://github.com/congwang/linux.git netrom OK
2019/07/18 18:06 11m xiyou.wangcong@gmail.com https://github.com/congwang/linux.git netrom report log

Sample crash report:
=========================
WARNING: held lock freed!
5.2.0+ #35 Not tainted
-------------------------
syz-executor619/8354 is freeing memory ffff88809309a140-ffff88809309a93f, with a lock still held there!
00000000bd3d25ac (sk_lock-AF_NETROM){+.+.}, at: lock_sock /./include/net/sock.h:1522 [inline]
00000000bd3d25ac (sk_lock-AF_NETROM){+.+.}, at: nr_release+0xfe/0x390 /net/netrom/af_netrom.c:522
2 locks held by syz-executor619/8354:
 #0: 0000000044454227 (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_lock /./include/linux/fs.h:778 [inline]
 #0: 0000000044454227 (&sb->s_type->i_mutex_key#11){+.+.}, at: __sock_release /net/socket.c:585 [inline]
 #0: 0000000044454227 (&sb->s_type->i_mutex_key#11){+.+.}, at: sock_close+0x9e/0x260 /net/socket.c:1264
 #1: 00000000bd3d25ac (sk_lock-AF_NETROM){+.+.}, at: lock_sock /./include/net/sock.h:1522 [inline]
 #1: 00000000bd3d25ac (sk_lock-AF_NETROM){+.+.}, at: nr_release+0xfe/0x390 /net/netrom/af_netrom.c:522

stack backtrace:
CPU: 0 PID: 8354 Comm: syz-executor619 Not tainted 5.2.0+ #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+0x1d8/0x2f8 /lib/dump_stack.c:113
 print_freed_lock_bug /kernel/locking/lockdep.c:5185 [inline]
 debug_check_no_locks_freed+0x813/0x990 /kernel/locking/lockdep.c:5218
 kfree+0xfb/0x200 /mm/slab.c:3753
 sk_prot_free /net/core/sock.c:1640 [inline]
 __sk_destruct+0x567/0x660 /net/core/sock.c:1726
 sk_destruct /net/core/sock.c:1734 [inline]
 __sk_free+0x317/0x3e0 /net/core/sock.c:1745
 sk_free+0x2a/0x40 /net/core/sock.c:1756
 sock_put /./include/net/sock.h:1725 [inline]
 nr_destroy_socket+0x3e3/0x460 /net/netrom/af_netrom.c:288
 nr_release+0x191/0x390 /net/netrom/af_netrom.c:530
 __sock_release /net/socket.c:586 [inline]
 sock_close+0xe1/0x260 /net/socket.c:1264
 __fput+0x2e4/0x740 /fs/file_table.c:280
 ____fput+0x15/0x20 /fs/file_table.c:313
 task_work_run+0x17e/0x1b0 /kernel/task_work.c:113
 exit_task_work /./include/linux/task_work.h:22 [inline]
 do_exit+0x64c/0x2310 /kernel/exit.c:877
 do_group_exit+0x15c/0x2b0 /kernel/exit.c:981
 get_signal+0x51c/0x1dd0 /kernel/signal.c:2728
 do_signal+0x7b/0x720 /arch/x86/kernel/signal.c:815
 exit_to_usermode_loop /arch/x86/entry/common.c:159 [inline]
 prepare_exit_to_usermode+0x303/0x580 /arch/x86/entry/common.c:194
 syscall_return_slowpath+0x113/0x4a0 /arch/x86/entry/common.c:274
 do_syscall_64+0x126/0x140 /arch/x86/entry/common.c:299
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x444839
Code: Bad RIP value.
RSP: 002b:00007ffdd7374068 EFLAGS: 00000246 ORIG_RAX: 000000000000002b
RAX: 0000000000000003 RBX: 0000000000000004 RCX: 0000000000444839
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 0000000000000003 R08: 0000000000000004 R09: 0000000000000004
R10: 0000000000000004 R11: 0000000000000246 R12: 0000555556c17914
R13: 0000000000000013 R14: 0000000000000000 R15: 0000000000000000
==================================================================
BUG: KASAN: use-after-free in debug_spin_lock_before /kernel/locking/spinlock_debug.c:83 [inline]
BUG: KASAN: use-after-free in do_raw_spin_lock+0x295/0x3a0 /kernel/locking/spinlock_debug.c:112
Read of size 4 at addr ffff88809309a1cc by task syz-executor619/8354

CPU: 0 PID: 8354 Comm: syz-executor619 Not tainted 5.2.0+ #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+0x1d8/0x2f8 /lib/dump_stack.c:113
 print_address_description+0x75/0x5b0 /mm/kasan/report.c:351
 __kasan_report+0x14b/0x1c0 /mm/kasan/report.c:482
 kasan_report+0x26/0x50 /mm/kasan/common.c:612
 __asan_report_load4_noabort+0x14/0x20 /mm/kasan/generic_report.c:131
 debug_spin_lock_before /kernel/locking/spinlock_debug.c:83 [inline]
 do_raw_spin_lock+0x295/0x3a0 /kernel/locking/spinlock_debug.c:112
 __raw_spin_lock_bh /./include/linux/spinlock_api_smp.h:136 [inline]
 _raw_spin_lock_bh+0x40/0x50 /kernel/locking/spinlock.c:175
 spin_lock_bh /./include/linux/spinlock.h:343 [inline]
 release_sock+0x30/0x1d0 /net/core/sock.c:2932
 nr_release+0x1b9/0x390 /net/netrom/af_netrom.c:553
 __sock_release /net/socket.c:586 [inline]
 sock_close+0xe1/0x260 /net/socket.c:1264
 __fput+0x2e4/0x740 /fs/file_table.c:280
 ____fput+0x15/0x20 /fs/file_table.c:313
 task_work_run+0x17e/0x1b0 /kernel/task_work.c:113
 exit_task_work /./include/linux/task_work.h:22 [inline]
 do_exit+0x64c/0x2310 /kernel/exit.c:877
 do_group_exit+0x15c/0x2b0 /kernel/exit.c:981
 get_signal+0x51c/0x1dd0 /kernel/signal.c:2728
 do_signal+0x7b/0x720 /arch/x86/kernel/signal.c:815
 exit_to_usermode_loop /arch/x86/entry/common.c:159 [inline]
 prepare_exit_to_usermode+0x303/0x580 /arch/x86/entry/common.c:194
 syscall_return_slowpath+0x113/0x4a0 /arch/x86/entry/common.c:274
 do_syscall_64+0x126/0x140 /arch/x86/entry/common.c:299
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x444839
Code: Bad RIP value.
RSP: 002b:00007ffdd7374068 EFLAGS: 00000246 ORIG_RAX: 000000000000002b
RAX: 0000000000000003 RBX: 0000000000000004 RCX: 0000000000444839
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 0000000000000003 R08: 0000000000000004 R09: 0000000000000004
R10: 0000000000000004 R11: 0000000000000246 R12: 0000555556c17914
R13: 0000000000000013 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 8363:
 save_stack /mm/kasan/common.c:69 [inline]
 set_track /mm/kasan/common.c:77 [inline]
 __kasan_kmalloc+0x11c/0x1b0 /mm/kasan/common.c:487
 kasan_kmalloc+0x9/0x10 /mm/kasan/common.c:501
 __do_kmalloc /mm/slab.c:3655 [inline]
 __kmalloc+0x254/0x340 /mm/slab.c:3664
 kmalloc /./include/linux/slab.h:557 [inline]
 sk_prot_alloc+0xb0/0x290 /net/core/sock.c:1603
 sk_alloc+0x38/0x950 /net/core/sock.c:1657
 nr_make_new /net/netrom/af_netrom.c:476 [inline]
 nr_rx_frame+0xabc/0x1e40 /net/netrom/af_netrom.c:959
 nr_loopback_timer+0x6a/0x140 /net/netrom/nr_loopback.c:59
 call_timer_fn+0xec/0x200 /kernel/time/timer.c:1322
 expire_timers /kernel/time/timer.c:1366 [inline]
 __run_timers+0x7cd/0x9c0 /kernel/time/timer.c:1685
 run_timer_softirq+0x4a/0x90 /kernel/time/timer.c:1698
 __do_softirq+0x333/0x7c4 /./arch/x86/include/asm/paravirt.h:777

Freed by task 8354:
 save_stack /mm/kasan/common.c:69 [inline]
 set_track /mm/kasan/common.c:77 [inline]
 __kasan_slab_free+0x12a/0x1e0 /mm/kasan/common.c:449
 kasan_slab_free+0xe/0x10 /mm/kasan/common.c:457
 __cache_free /mm/slab.c:3425 [inline]
 kfree+0x115/0x200 /mm/slab.c:3756
 sk_prot_free /net/core/sock.c:1640 [inline]
 __sk_destruct+0x567/0x660 /net/core/sock.c:1726
 sk_destruct /net/core/sock.c:1734 [inline]
 __sk_free+0x317/0x3e0 /net/core/sock.c:1745
 sk_free+0x2a/0x40 /net/core/sock.c:1756
 sock_put /./include/net/sock.h:1725 [inline]
 nr_destroy_socket+0x3e3/0x460 /net/netrom/af_netrom.c:288
 nr_release+0x191/0x390 /net/netrom/af_netrom.c:530
 __sock_release /net/socket.c:586 [inline]
 sock_close+0xe1/0x260 /net/socket.c:1264
 __fput+0x2e4/0x740 /fs/file_table.c:280
 ____fput+0x15/0x20 /fs/file_table.c:313
 task_work_run+0x17e/0x1b0 /kernel/task_work.c:113
 exit_task_work /./include/linux/task_work.h:22 [inline]
 do_exit+0x64c/0x2310 /kernel/exit.c:877
 do_group_exit+0x15c/0x2b0 /kernel/exit.c:981
 get_signal+0x51c/0x1dd0 /kernel/signal.c:2728
 do_signal+0x7b/0x720 /arch/x86/kernel/signal.c:815
 exit_to_usermode_loop /arch/x86/entry/common.c:159 [inline]
 prepare_exit_to_usermode+0x303/0x580 /arch/x86/entry/common.c:194
 syscall_return_slowpath+0x113/0x4a0 /arch/x86/entry/common.c:274
 do_syscall_64+0x126/0x140 /arch/x86/entry/common.c:299
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88809309a140
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 140 bytes inside of
 2048-byte region [ffff88809309a140, ffff88809309a940)
The buggy address belongs to the page:
page:ffffea00024c2680 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea000262ce08 ffffea000229e408 ffff8880aa400e00
raw: 0000000000000000 ffff88809309a140 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809309a080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809309a100: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff88809309a180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff88809309a200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809309a280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (344):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/07/20 02:37 upstream 3bfe1fc46794 1656845f .config console log report syz C ci-upstream-kasan-gce-smack-root
2019/07/17 08:37 upstream 3eb514866f20 0d10349c .config console log report syz C ci-upstream-kasan-gce-root
2019/07/17 07:50 upstream 3eb514866f20 0d10349c .config console log report syz C ci-upstream-kasan-gce-selinux-root
2019/07/17 07:14 net-old a5b647007e9d 0d10349c .config console log report syz C ci-upstream-net-this-kasan-gce
2019/07/25 03:16 linux-next 9e6dfe8045f8 32329ceb .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2019/07/17 09:11 upstream 3eb514866f20 0d10349c .config console log report syz ci-upstream-kasan-gce-selinux-root
2019/07/17 08:33 upstream 3eb514866f20 0d10349c .config console log report syz ci-upstream-kasan-gce-smack-root
2019/07/17 05:58 net-old a5b647007e9d 0d10349c .config console log report syz ci-upstream-net-this-kasan-gce
2019/07/17 11:08 net-next-old 192f0f8e9db7 0d10349c .config console log report syz ci-upstream-net-kasan-gce
2019/07/17 08:28 linux-next e40115c06b1d 0d10349c .config console log report syz ci-upstream-linux-next-kasan-gce-root
2019/07/17 07:08 linux-next e40115c06b1d 0d10349c .config console log report syz ci-upstream-linux-next-kasan-gce-root
2019/07/24 08:10 upstream c6dd78fcb8ee de453f34 .config console log report ci-upstream-kasan-gce-selinux-root
2019/07/20 14:20 upstream abdfd52a295f 1656845f .config console log report ci-upstream-kasan-gce-root
2019/08/07 01:53 net-old 107e47cc80ec c6f01e54 .config console log report ci-upstream-net-this-kasan-gce
2019/08/06 15:54 net-old 107e47cc80ec c6f01e54 .config console log report ci-upstream-net-this-kasan-gce
2019/08/05 23:46 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/05 20:56 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/05 19:45 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/05 18:04 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/05 10:37 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/05 01:05 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/04 23:00 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/04 21:18 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/04 15:34 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/04 11:14 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/04 07:28 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/04 03:42 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/04 02:34 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/03 17:13 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/03 08:15 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/03 03:25 net-old 107e47cc80ec 6affd8e8 .config console log report ci-upstream-net-this-kasan-gce
2019/08/02 18:06 net-old 107e47cc80ec 835dffe7 .config console log report ci-upstream-net-this-kasan-gce
2019/08/07 04:26 net-next-old 31cc088a4f5d c6f01e54 .config console log report ci-upstream-net-kasan-gce
2019/08/06 23:52 net-next-old 31cc088a4f5d c6f01e54 .config console log report ci-upstream-net-kasan-gce
2019/08/06 17:13 net-next-old 31cc088a4f5d c6f01e54 .config console log report ci-upstream-net-kasan-gce
2019/08/06 12:13 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/06 08:29 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/06 06:54 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/06 04:42 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/06 03:09 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/06 01:06 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/05 22:04 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/05 16:46 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/05 14:10 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/05 09:30 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/05 07:00 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/04 17:25 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/04 14:28 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/04 09:52 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/04 07:18 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/03 22:37 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/03 20:57 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/03 13:15 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/03 09:37 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/03 06:41 net-next-old 31cc088a4f5d 6affd8e8 .config console log report ci-upstream-net-kasan-gce
2019/08/02 16:25 net-next-old 31cc088a4f5d 835dffe7 .config console log report ci-upstream-net-kasan-gce
2019/07/17 02:21 net-next-old 192f0f8e9db7 0d10349c .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.