syzbot

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BUG: KASAN: use-after-free in __lock_acquire+0x34ac/0x49c0 kernel/locking/lockdep.c:3290
Read of size 8 at addr ffff88808fe57720 by task syz-executor.1/11303

CPU: 0 PID: 11303 Comm: syz-executor.1 Not tainted 4.19.80 #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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 __lock_acquire+0x34ac/0x49c0 kernel/locking/lockdep.c:3290
 lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3903
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x33/0x50 kernel/locking/spinlock.c:168
 spin_lock_bh include/linux/spinlock.h:334 [inline]
 __lock_sock+0x16d/0x290 net/core/sock.c:2316
 lock_sock_nested+0xfe/0x120 net/core/sock.c:2840
 lock_sock include/net/sock.h:1501 [inline]
 sctp_sock_dump+0x122/0xb20 net/sctp/diag.c:325
 sctp_for_each_transport+0x2b4/0x350 net/sctp/socket.c:5078
 sctp_diag_dump+0x33e/0x450 net/sctp/diag.c:528
 __inet_diag_dump+0x9e/0x130 net/ipv4/inet_diag.c:1059
 inet_diag_dump+0x9b/0x110 net/ipv4/inet_diag.c:1075
 netlink_dump+0x427/0xbb0 net/netlink/af_netlink.c:2233
 __netlink_dump_start+0x508/0x700 net/netlink/af_netlink.c:2329
 netlink_dump_start include/linux/netlink.h:213 [inline]
 inet_diag_handler_cmd+0x262/0x320 net/ipv4/inet_diag.c:1180
 __sock_diag_cmd net/core/sock_diag.c:232 [inline]
 sock_diag_rcv_msg+0x319/0x410 net/core/sock_diag.c:263
 netlink_rcv_skb+0x17d/0x460 net/netlink/af_netlink.c:2454
 sock_diag_rcv+0x2b/0x40 net/core/sock_diag.c:274
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x537/0x720 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1908
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:632
 sock_write_iter+0x27c/0x3e0 net/socket.c:901
 call_write_iter include/linux/fs.h:1820 [inline]
 do_iter_readv_writev+0x558/0x830 fs/read_write.c:681
 do_iter_write fs/read_write.c:960 [inline]
 do_iter_write+0x184/0x5f0 fs/read_write.c:941
 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1005
 do_writev+0x15e/0x370 fs/read_write.c:1040
 __do_sys_writev fs/read_write.c:1113 [inline]
 __se_sys_writev fs/read_write.c:1110 [inline]
 __x64_sys_writev+0x75/0xb0 fs/read_write.c:1110
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459f39
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f713fe7ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459f39
RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 000000000075c118 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f713fe7b6d4
R13: 00000000004c76b0 R14: 00000000004e28d8 R15: 00000000ffffffff

Allocated by task 11281:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc mm/kasan/kasan.c:553 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531
 kasan_slab_alloc+0xf/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x700 mm/slab.c:3559
 sk_prot_alloc+0x67/0x2e0 net/core/sock.c:1460
 sk_alloc+0x39/0xf70 net/core/sock.c:1520
 inet6_create net/ipv6/af_inet6.c:183 [inline]
 inet6_create+0x360/0xf70 net/ipv6/af_inet6.c:110
 __sock_create+0x3d8/0x730 net/socket.c:1276
 sock_create net/socket.c:1316 [inline]
 __sys_socket+0x103/0x220 net/socket.c:1346
 __do_sys_socket net/socket.c:1355 [inline]
 __se_sys_socket net/socket.c:1353 [inline]
 __x64_sys_socket+0x73/0xb0 net/socket.c:1353
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 11280:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3503 [inline]
 kmem_cache_free+0x86/0x260 mm/slab.c:3765
 sk_prot_free net/core/sock.c:1501 [inline]
 __sk_destruct+0x479/0x680 net/core/sock.c:1583
 sk_destruct+0xc8/0x100 net/core/sock.c:1598
 __sk_free+0xce/0x300 net/core/sock.c:1609
 sk_free+0x42/0x50 net/core/sock.c:1620
 sock_put include/net/sock.h:1702 [inline]
 sctp_close+0x70f/0x860 net/sctp/socket.c:1587
 inet_release+0xff/0x1e0 net/ipv4/af_inet.c:428
 inet6_release+0x53/0x80 net/ipv6/af_inet6.c:472
 __sock_release+0xce/0x2a0 net/socket.c:579
 sock_close+0x1b/0x30 net/socket.c:1140
 __fput+0x2dd/0x8b0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:167
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88808fe57680
 which belongs to the cache SCTPv6(61:syz1) of size 1928
The buggy address is located 160 bytes inside of
 1928-byte region [ffff88808fe57680, ffff88808fe57e08)
The buggy address belongs to the page:
page:ffffea00023f9580 count:1 mapcount:0 mapping:ffff888095e59040 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000008100(slab|head)
raw: 01fffc0000008100 ffffea00023ca288 ffffea0002000288 ffff888095e59040
raw: 0000000000000000 ffff88808fe56600 0000000100000003 ffff88809836e7c0
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff88809836e7c0

Memory state around the buggy address:
 ffff88808fe57600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808fe57680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88808fe57700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff88808fe57780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808fe57800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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