=========================
WARNING: held lock freed!
4.15.0-rc7+ #190 Not tainted
-------------------------
syz-executor6/8067 is freeing memory 000000000c4b9c27-000000009d207436, with a lock still held there!
 (sk_lock-AF_INET6){+.+.}, at: [<000000006486a5b5>] lock_sock include/net/sock.h:1463 [inline]
 (sk_lock-AF_INET6){+.+.}, at: [<000000006486a5b5>] sctp_wait_for_sndbuf+0x509/0x8d0 net/sctp/socket.c:8161
1 lock held by syz-executor6/8067:
 #0:  (sk_lock-AF_INET6){+.+.}, at: [<000000006486a5b5>] lock_sock include/net/sock.h:1463 [inline]
 #0:  (sk_lock-AF_INET6){+.+.}, at: [<000000006486a5b5>] sctp_wait_for_sndbuf+0x509/0x8d0 net/sctp/socket.c:8161

stack backtrace:
CPU: 1 PID: 8067 Comm: syz-executor6 Not tainted 4.15.0-rc7+ #190
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+0x194/0x257 lib/dump_stack.c:53
 print_freed_lock_bug kernel/locking/lockdep.c:4379 [inline]
 debug_check_no_locks_freed+0x32f/0x3c0 kernel/locking/lockdep.c:4412
 kmem_cache_free+0x68/0x2a0 mm/slab.c:3743
 sk_prot_free net/core/sock.c:1506 [inline]
 __sk_destruct+0x622/0x910 net/core/sock.c:1590
 sk_destruct+0x47/0x80 net/core/sock.c:1598
 __sk_free+0xf1/0x2b0 net/core/sock.c:1609
 sk_free+0x2a/0x40 net/core/sock.c:1620
 sock_put include/net/sock.h:1658 [inline]
 sctp_association_destroy net/sctp/associola.c:424 [inline]
 sctp_association_put+0x14c/0x2f0 net/sctp/associola.c:883
 sctp_wait_for_sndbuf+0x673/0x8d0 net/sctp/socket.c:8172
 sctp_sendmsg+0x28f7/0x33f0 net/sctp/socket.c:1991
 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:640
 SYSC_sendto+0x361/0x5c0 net/socket.c:1721
 SyS_sendto+0x40/0x50 net/socket.c:1689
 entry_SYSCALL_64_fastpath+0x23/0x9a
RIP: 0033:0x452df9
RSP: 002b:00007fcf1ed35c58 EFLAGS: 00000212 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000000000071c010 RCX: 0000000000452df9
RDX: 0000000000000001 RSI: 000000002010bf14 RDI: 0000000000000013
RBP: 0000000000000576 R08: 00000000204d9000 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f63b0
R13: 00000000ffffffff R14: 00007fcf1ed366d4 R15: 0000000000000004
==================================================================
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+0x1e0/0x220 kernel/locking/spinlock_debug.c:112
Read of size 4 at addr ffff8801d05a008c by task syz-executor6/8067

CPU: 1 PID: 8067 Comm: syz-executor6 Not tainted 4.15.0-rc7+ #190
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+0x194/0x257 lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429
 debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
 do_raw_spin_lock+0x1e0/0x220 kernel/locking/spinlock_debug.c:112
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
 _raw_spin_lock_bh+0x39/0x40 kernel/locking/spinlock.c:168
 spin_lock_bh include/linux/spinlock.h:315 [inline]
 release_sock+0x74/0x2a0 net/core/sock.c:2787
 sctp_sendmsg+0x2993/0x33f0 net/sctp/socket.c:2088
 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:640
 SYSC_sendto+0x361/0x5c0 net/socket.c:1721
 SyS_sendto+0x40/0x50 net/socket.c:1689
 entry_SYSCALL_64_fastpath+0x23/0x9a
RIP: 0033:0x452df9
RSP: 002b:00007fcf1ed35c58 EFLAGS: 00000212 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000000000071c010 RCX: 0000000000452df9
RDX: 0000000000000001 RSI: 000000002010bf14 RDI: 0000000000000013
RBP: 0000000000000576 R08: 00000000204d9000 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f63b0
R13: 00000000ffffffff R14: 00007fcf1ed366d4 R15: 0000000000000004

Allocated by task 8069:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3544
 sk_prot_alloc+0x65/0x2a0 net/core/sock.c:1465
 sk_alloc+0x105/0x1440 net/core/sock.c:1525
 sctp_v6_create_accept_sk+0x15a/0x9b0 net/sctp/ipv6.c:667
 sctp_accept+0x5c4/0x970 net/sctp/socket.c:4395
 inet_accept+0x12c/0x930 net/ipv4/af_inet.c:699
 SYSC_accept4+0x38d/0x870 net/socket.c:1545
 SyS_accept4+0x2c/0x40 net/socket.c:1496
 entry_SYSCALL_64_fastpath+0x23/0x9a

Freed by task 8067:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3488 [inline]
 kmem_cache_free+0x83/0x2a0 mm/slab.c:3746
 sk_prot_free net/core/sock.c:1506 [inline]
 __sk_destruct+0x622/0x910 net/core/sock.c:1590
 sk_destruct+0x47/0x80 net/core/sock.c:1598
 __sk_free+0xf1/0x2b0 net/core/sock.c:1609
 sk_free+0x2a/0x40 net/core/sock.c:1620
 sock_put include/net/sock.h:1658 [inline]
 sctp_association_destroy net/sctp/associola.c:424 [inline]
 sctp_association_put+0x14c/0x2f0 net/sctp/associola.c:883
 sctp_wait_for_sndbuf+0x673/0x8d0 net/sctp/socket.c:8172
 sctp_sendmsg+0x28f7/0x33f0 net/sctp/socket.c:1991
 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:640
 SYSC_sendto+0x361/0x5c0 net/socket.c:1721
 SyS_sendto+0x40/0x50 net/socket.c:1689
 entry_SYSCALL_64_fastpath+0x23/0x9a

The buggy address belongs to the object at ffff8801d05a0000
 which belongs to the cache SCTPv6 of size 1888
The buggy address is located 140 bytes inside of
 1888-byte region [ffff8801d05a0000, ffff8801d05a0760)
The buggy address belongs to the page:
page:ffffea0007416800 count:1 mapcount:0 mapping:ffff8801d05a0000 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d05a0000 0000000000000000 0000000100000002
raw: ffffea00070a3b60 ffff8801d2c91d48 ffff8801d2c89380 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d059ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801d05a0000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801d05a0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff8801d05a0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d05a0180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================