audit: type=1326 audit(1521624067.102:21): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=7057 comm="syz-executor3" exe="/root/syz-executor3" sig=9 arch=c000003e syscall=202 compat=0 ip=0x453e69 code=0x0
======================================================
[ INFO: possible circular locking dependency detected ]
4.4.120-gd63fdf6 #28 Not tainted
-------------------------------------------------------
syz-executor6/7062 is trying to acquire lock:
 (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<ffffffff81463361>] shmem_file_llseek+0xf1/0x240 mm/shmem.c:1816

but task is already holding lock:
 (ashmem_mutex){+.+.+.}, at: [<ffffffff82c62016>] ashmem_llseek+0x56/0x1f0 drivers/staging/android/ashmem.c:330

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

 (ashmem_mutex){+.+.+.}:
       [<ffffffff8123d7ce>] lock_acquire+0x15e/0x460 kernel/locking/lockdep.c:3592
       [<ffffffff8376a39b>] __mutex_lock_common kernel/locking/mutex.c:521 [inline]
       [<ffffffff8376a39b>] mutex_lock_nested+0xbb/0x850 kernel/locking/mutex.c:621
       [<ffffffff82c61463>] ashmem_mmap+0x53/0x400 drivers/staging/android/ashmem.c:366
       [<ffffffff814b0e4f>] mmap_region+0x94f/0x1250 mm/mmap.c:1664
       [<ffffffff814b1c4d>] do_mmap+0x4fd/0x9d0 mm/mmap.c:1441
       [<ffffffff814700ce>] do_mmap_pgoff include/linux/mm.h:1915 [inline]
       [<ffffffff814700ce>] vm_mmap_pgoff+0x16e/0x1c0 mm/util.c:296
       [<ffffffff814afe1f>] SYSC_mmap_pgoff mm/mmap.c:1491 [inline]
       [<ffffffff814afe1f>] SyS_mmap_pgoff+0x33f/0x560 mm/mmap.c:1449
       [<ffffffff8101beb6>] SYSC_mmap arch/x86/kernel/sys_x86_64.c:95 [inline]
       [<ffffffff8101beb6>] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:86
       [<ffffffff8377395f>] entry_SYSCALL_64_fastpath+0x1c/0x98

       [<ffffffff8123d7ce>] lock_acquire+0x15e/0x460 kernel/locking/lockdep.c:3592
       [<ffffffff814956ea>] __might_fault+0x14a/0x1d0 mm/memory.c:3810
       [<ffffffff8155ab22>] copy_to_user arch/x86/include/asm/uaccess.h:760 [inline]
       [<ffffffff8155ab22>] filldir+0x162/0x2d0 fs/readdir.c:180
       [<ffffffff8159820e>] dir_emit_dot include/linux/fs.h:3070 [inline]
       [<ffffffff8159820e>] dir_emit_dots include/linux/fs.h:3081 [inline]
       [<ffffffff8159820e>] dcache_readdir+0x11e/0x7b0 fs/libfs.c:150
       [<ffffffff8155a768>] iterate_dir+0x1c8/0x420 fs/readdir.c:42
       [<ffffffff8155b45a>] SYSC_getdents fs/readdir.c:215 [inline]
       [<ffffffff8155b45a>] SyS_getdents+0x14a/0x270 fs/readdir.c:196
       [<ffffffff8377395f>] entry_SYSCALL_64_fastpath+0x1c/0x98

       [<ffffffff8123ab2f>] check_prev_add kernel/locking/lockdep.c:1853 [inline]
       [<ffffffff8123ab2f>] check_prevs_add kernel/locking/lockdep.c:1958 [inline]
       [<ffffffff8123ab2f>] validate_chain kernel/locking/lockdep.c:2144 [inline]
       [<ffffffff8123ab2f>] __lock_acquire+0x371f/0x4b50 kernel/locking/lockdep.c:3213
       [<ffffffff8123d7ce>] lock_acquire+0x15e/0x460 kernel/locking/lockdep.c:3592
       [<ffffffff8376a39b>] __mutex_lock_common kernel/locking/mutex.c:521 [inline]
       [<ffffffff8376a39b>] mutex_lock_nested+0xbb/0x850 kernel/locking/mutex.c:621
       [<ffffffff81463361>] shmem_file_llseek+0xf1/0x240 mm/shmem.c:1816
       [<ffffffff8151c762>] vfs_llseek+0xa2/0xd0 fs/read_write.c:260
       [<ffffffff82c620a7>] ashmem_llseek+0xe7/0x1f0 drivers/staging/android/ashmem.c:342
       [<ffffffff8151e56b>] vfs_llseek fs/read_write.c:260 [inline]
       [<ffffffff8151e56b>] SYSC_lseek fs/read_write.c:285 [inline]
       [<ffffffff8151e56b>] SyS_lseek+0xeb/0x170 fs/read_write.c:276
       [<ffffffff8377395f>] entry_SYSCALL_64_fastpath+0x1c/0x98

other info that might help us debug this:

Chain exists of:
 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(ashmem_mutex);
                               lock(&mm->mmap_sem);
                               lock(ashmem_mutex);
  lock(&sb->s_type->i_mutex_key#10);

 *** DEADLOCK ***

1 lock held by syz-executor6/7062:
 #0:  (ashmem_mutex){+.+.+.}, at: [<ffffffff82c62016>] ashmem_llseek+0x56/0x1f0 drivers/staging/android/ashmem.c:330

stack backtrace:
CPU: 0 PID: 7062 Comm: syz-executor6 Not tainted 4.4.120-gd63fdf6 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 779e800ee5c531fa ffff8801d67bfad8 ffffffff81d0408d
 ffffffff8519fe60 ffffffff851a9b50 ffffffff851be610 ffff8801d4f2d0f8
 ffff8801d4f2c800 ffff8801d67bfb20 ffffffff81233ba1 ffff8801d4f2d0f8
Call Trace:
 [<ffffffff81d0408d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0408d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81233ba1>] print_circular_bug+0x271/0x310 kernel/locking/lockdep.c:1226
 [<ffffffff8123ab2f>] check_prev_add kernel/locking/lockdep.c:1853 [inline]
 [<ffffffff8123ab2f>] check_prevs_add kernel/locking/lockdep.c:1958 [inline]
 [<ffffffff8123ab2f>] validate_chain kernel/locking/lockdep.c:2144 [inline]
 [<ffffffff8123ab2f>] __lock_acquire+0x371f/0x4b50 kernel/locking/lockdep.c:3213
 [<ffffffff8123d7ce>] lock_acquire+0x15e/0x460 kernel/locking/lockdep.c:3592
 [<ffffffff8376a39b>] __mutex_lock_common kernel/locking/mutex.c:521 [inline]
 [<ffffffff8376a39b>] mutex_lock_nested+0xbb/0x850 kernel/locking/mutex.c:621
 [<ffffffff81463361>] shmem_file_llseek+0xf1/0x240 mm/shmem.c:1816
 [<ffffffff8151c762>] vfs_llseek+0xa2/0xd0 fs/read_write.c:260
 [<ffffffff82c620a7>] ashmem_llseek+0xe7/0x1f0 drivers/staging/android/ashmem.c:342
 [<ffffffff8151e56b>] vfs_llseek fs/read_write.c:260 [inline]
 [<ffffffff8151e56b>] SYSC_lseek fs/read_write.c:285 [inline]
 [<ffffffff8151e56b>] SyS_lseek+0xeb/0x170 fs/read_write.c:276
 [<ffffffff8377395f>] entry_SYSCALL_64_fastpath+0x1c/0x98
binder: 7103:7108 got new transaction with bad transaction stack, transaction 21 has target 7103:0
binder: 7103:7108 transaction failed 29201/-71, size 0-0 line 3032
binder: BINDER_SET_CONTEXT_MGR already set
binder_alloc: binder_alloc_mmap_handler: 7125 20000000-20400000 already mapped failed -16
binder: 7103:7120 ioctl 40046207 0 returned -16
binder: 7103:7120 got transaction to invalid handle
binder: 7103:7120 transaction failed 29201/-22, size 0-0 line 3005
binder_alloc: 7103: binder_alloc_buf, no vma
binder: 7103:7108 transaction failed 29189/-3, size 40-8 line 3128
binder: undelivered TRANSACTION_ERROR: 29189
binder: undelivered TRANSACTION_ERROR: 29201
binder: release 7103:7108 transaction 21 out, still active
binder: unexpected work type, 4, not freed
binder: undelivered TRANSACTION_COMPLETE
binder: undelivered TRANSACTION_ERROR: 29201
binder: send failed reply for transaction 21, target dead
binder: 7197:7201 BC_CLEAR_DEATH_NOTIFICATION death notification cookie mismatch 00000000000000cb != 0000000000000000
binder: BINDER_SET_CONTEXT_MGR already set
binder: 7197:7215 ioctl 40046207 0 returned -16
binder: 7197:7215 BC_CLEAR_DEATH_NOTIFICATION death notification cookie mismatch 00000000000000cb != 0000000000000000
FAULT_FLAG_ALLOW_RETRY missing 30
CPU: 0 PID: 7456 Comm: syz-executor3 Not tainted 4.4.120-gd63fdf6 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 3e797ad5b3cab92b ffff8800a8b6f970 ffffffff81d0408d
 ffff8800b491ac00 1ffff1001516df3b ffff8800a8b6faf8 0000000000000000
 0000000000000000 ffff8800a8b6fb20 ffffffff81607305 ffffffff81237410
Call Trace:
 [<ffffffff81d0408d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0408d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81607305>] handle_userfault+0x715/0xf50 fs/userfaultfd.c:316
 [<ffffffff814a2d88>] do_anonymous_page mm/memory.c:2731 [inline]
 [<ffffffff814a2d88>] handle_pte_fault mm/memory.c:3295 [inline]
 [<ffffffff814a2d88>] __handle_mm_fault mm/memory.c:3426 [inline]
 [<ffffffff814a2d88>] handle_mm_fault+0x2938/0x3190 mm/memory.c:3455
 [<ffffffff810dc6cb>] __do_page_fault+0x35b/0xa00 arch/x86/mm/fault.c:1245
 [<ffffffff810dcd97>] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1308
 [<ffffffff83774d88>] page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1033
 [<ffffffff8377395f>] entry_SYSCALL_64_fastpath+0x1c/0x98
audit: type=1400 audit(1521624069.222:23): avc:  denied  { read } for  pid=7483 comm="syz-executor1" path="socket:[17249]" dev="sockfs" ino=17249 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1
IPv4: Oversized IP packet from 127.0.0.1
binder: 7485:7498 BC_REQUEST_DEATH_NOTIFICATION invalid ref 0
audit: type=1400 audit(1521624069.722:24): avc:  denied  { setopt } for  pid=7623 comm="syz-executor3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1
IPVS: Creating netns size=2552 id=9
pktgen: kernel_thread() failed for cpu 0
pktgen: Cannot create thread for cpu 0 (-4)
pktgen: kernel_thread() failed for cpu 1
pktgen: Cannot create thread for cpu 1 (-4)
pktgen: Initialization failed for all threads
keychord: invalid keycode count 0
keychord: invalid keycode count 0
IPv4: Oversized IP packet from 127.0.0.1
BUG: using __this_cpu_read() in preemptible [00000000] code: syz-executor4/7866
caller is __this_cpu_preempt_check+0x1c/0x20 lib/smp_processor_id.c:62
CPU: 1 PID: 7866 Comm: syz-executor4 Not tainted 4.4.120-gd63fdf6 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 ff699a92283eecff ffff8801d2527480 ffffffff81d0408d
 0000000000000001 ffffffff839fe5a0 ffffffff83d0be20 ffff8801d4fcb000
 0000000000000003 ffff8801d25274c0 ffffffff81d63fe4 ffff8801d25274d8
Call Trace:
 [<ffffffff81d0408d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0408d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81d63fe4>] check_preemption_disabled+0x1d4/0x200 lib/smp_processor_id.c:46
 [<ffffffff81d6404c>] __this_cpu_preempt_check+0x1c/0x20 lib/smp_processor_id.c:62
 [<ffffffff832e2f08>] ipcomp_alloc_tfms net/xfrm/xfrm_ipcomp.c:286 [inline]
 [<ffffffff832e2f08>] ipcomp_init_state+0x188/0x980 net/xfrm/xfrm_ipcomp.c:363
 [<ffffffff8324ac70>] ipcomp4_init_state+0xb0/0x7d0 net/ipv4/ipcomp.c:137
 [<ffffffff832c1817>] __xfrm_init_state+0x3e7/0xb30 net/xfrm/xfrm_state.c:2058
 [<ffffffff832e06f6>] xfrm_state_construct net/xfrm/xfrm_user.c:590 [inline]
 [<ffffffff832e06f6>] xfrm_add_sa+0x1916/0x2e40 net/xfrm/xfrm_user.c:636
 [<ffffffff832d0bfc>] xfrm_user_rcv_msg+0x41c/0x6b0 net/xfrm/xfrm_user.c:2549
 [<ffffffff82f8b56e>] netlink_rcv_skb+0x13e/0x370 net/netlink/af_netlink.c:2349
 [<ffffffff832cd12f>] xfrm_netlink_rcv+0x6f/0x90 net/xfrm/xfrm_user.c:2557
 [<ffffffff82f8a0f2>] netlink_unicast_kernel net/netlink/af_netlink.c:1267 [inline]
 [<ffffffff82f8a0f2>] netlink_unicast+0x522/0x760 net/netlink/af_netlink.c:1293
 [<ffffffff82f8ac18>] netlink_sendmsg+0x8e8/0xc50 net/netlink/af_netlink.c:1847
 [<ffffffff82deba6a>] sock_sendmsg_nosec net/socket.c:625 [inline]
 [<ffffffff82deba6a>] sock_sendmsg+0xca/0x110 net/socket.c:635
 [<ffffffff82ded641>] ___sys_sendmsg+0x6c1/0x7c0 net/socket.c:1962
 [<ffffffff82def693>] __sys_sendmsg+0xd3/0x190 net/socket.c:1996
 [<ffffffff82def77d>] SYSC_sendmsg net/socket.c:2007 [inline]
 [<ffffffff82def77d>] SyS_sendmsg+0x2d/0x50 net/socket.c:2003
 [<ffffffff8377395f>] entry_SYSCALL_64_fastpath+0x1c/0x98
netlink: 2 bytes leftover after parsing attributes in process `syz-executor6'.
netlink: 2 bytes leftover after parsing attributes in process `syz-executor6'.
capability: warning: `syz-executor5' uses deprecated v2 capabilities in a way that may be insecure
netlink: 2 bytes leftover after parsing attributes in process `syz-executor6'.
netlink: 2 bytes leftover after parsing attributes in process `syz-executor6'.
audit: type=1400 audit(1521624071.632:25): avc:  denied  { dyntransition } for  pid=7960 comm="syz-executor7" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0,c1 tclass=process permissive=1
binder: send failed reply for transaction 31 to 7968:7975
binder: 7968:7975 BC_INCREFS_DONE node 34 has no pending increfs request
netlink: 2 bytes leftover after parsing attributes in process `syz-executor6'.
binder: 7968:7992 ioctl 80000001 20000000 returned -22
netlink: 2 bytes leftover after parsing attributes in process `syz-executor6'.
binder: BINDER_SET_CONTEXT_MGR already set
binder: 7968:7975 ioctl 40046207 0 returned -16
binder_alloc: binder_alloc_mmap_handler: 7968 20000000-20002000 already mapped failed -16
binder_alloc: 7968: binder_alloc_buf, no vma
keychord: invalid keycode count 0
binder: 7968:8007 transaction failed 29189/-3, size 40-8 line 3128
keychord: invalid keycode count 0
binder: BINDER_SET_CONTEXT_MGR already set
binder: 7968:7975 ioctl 40046207 0 returned -16
binder: 7968:7992 BC_INCREFS_DONE u0000000000000000 no match
netlink: 2 bytes leftover after parsing attributes in process `syz-executor6'.
binder: undelivered TRANSACTION_ERROR: 29189
netlink: 2 bytes leftover after parsing attributes in process `syz-executor6'.
netlink: 2 bytes leftover after parsing attributes in process `syz-executor6'.
netlink: 2 bytes leftover after parsing attributes in process `syz-executor6'.
binder: release 8170:8173 transaction 37 out, still active
binder: 8170:8183 got reply transaction with no transaction stack
binder: undelivered TRANSACTION_COMPLETE
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=257 sclass=netlink_route_socket
binder: 8170:8173 unknown command -1581709053
binder: 8170:8173 ioctl c0306201 20000140 returned -22
binder: BINDER_SET_CONTEXT_MGR already set
binder: 8170:8173 ioctl 40046207 0 returned -16
binder_alloc: 8170: binder_alloc_buf, no vma
binder: 8170:8183 transaction failed 29201/-71, size 56-32 line 2921
binder: 8170:8193 transaction failed 29189/-3, size 0-0 line 3128
binder: 8170:8183 unknown command -1581709053
binder: 8170:8173 got reply transaction with no transaction stack
binder: 8170:8173 transaction failed 29201/-71, size 56-32 line 2921
binder: 8170:8183 ioctl c0306201 20000140 returned -22
binder: undelivered TRANSACTION_ERROR: 29189
binder: send failed reply for transaction 37, target dead
BUG: using __this_cpu_add() in preemptible [00000000] code: syz-executor7/8207
caller is __this_cpu_preempt_check+0x1c/0x20 lib/smp_processor_id.c:62
CPU: 1 PID: 8207 Comm: syz-executor7 Not tainted 4.4.120-gd63fdf6 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 4164e5f59ca29cdc ffff8800b576f638 ffffffff81d0408d
 0000000000000001 ffffffff839fe5a0 ffffffff83cefc20 ffff8800b5fc6000
 0000000000000003 ffff8800b576f678 ffffffff81d63fe4 ffff8800bb9d5988
Call Trace:
 [<ffffffff81d0408d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0408d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81d63fe4>] check_preemption_disabled+0x1d4/0x200 lib/smp_processor_id.c:46
 [<ffffffff81d6404c>] __this_cpu_preempt_check+0x1c/0x20 lib/smp_processor_id.c:62
 [<ffffffff8312b439>] tcp_try_coalesce+0x249/0x4d0 net/ipv4/tcp_input.c:4278
 [<ffffffff831335b7>] tcp_queue_rcv+0x127/0x720 net/ipv4/tcp_input.c:4485
 [<ffffffff8314ae8b>] tcp_send_rcvq+0x39b/0x450 net/ipv4/tcp_input.c:4531
 [<ffffffff831220ef>] tcp_sendmsg+0x1e8f/0x2b10 net/ipv4/tcp.c:1134
 [<ffffffff831d7d4c>] inet_sendmsg+0x2bc/0x4c0 net/ipv4/af_inet.c:755
 [<ffffffff82deba6a>] sock_sendmsg_nosec net/socket.c:625 [inline]
 [<ffffffff82deba6a>] sock_sendmsg+0xca/0x110 net/socket.c:635
 [<ffffffff82debcd6>] sock_write_iter+0x226/0x3b0 net/socket.c:834
 [<ffffffff8151e0b8>] do_iter_readv_writev+0x138/0x1e0 fs/read_write.c:664
 [<ffffffff8151f852>] do_readv_writev+0x2d2/0x6e0 fs/read_write.c:808
 [<ffffffff8151fd8b>] vfs_writev+0x7b/0xb0 fs/read_write.c:847
 [<ffffffff81522249>] SYSC_writev fs/read_write.c:880 [inline]
 [<ffffffff81522249>] SyS_writev+0xd9/0x240 fs/read_write.c:872
 [<ffffffff8377395f>] entry_SYSCALL_64_fastpath+0x1c/0x98
audit: type=1400 audit(1521624073.132:26): avc:  denied  { getopt } for  pid=8291 comm="syz-executor3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1
binder: 8466:8469 ioctl c0306201 20007000 returned -14
binder_alloc: binder_alloc_mmap_handler: 8466 20000000-20002000 already mapped failed -16
binder: 8466:8469 ioctl c0306201 20007000 returned -14
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=26463 sclass=netlink_route_socket
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=26463 sclass=netlink_route_socket
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=61440 sclass=netlink_route_socket
audit: type=1400 audit(1521624074.582:27): avc:  denied  { setattr } for  pid=8584 comm="syz-executor3" name="NETLINK" dev="sockfs" ino=19640 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=61440 sclass=netlink_route_socket
audit: type=1400 audit(1521624074.732:28): avc:  denied  { lock } for  pid=8600 comm="syz-executor7" path="socket:[19670]" dev="sockfs" ino=19670 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1
BUG: using __this_cpu_read() in preemptible [00000000] code: syz-executor2/8770
caller is __this_cpu_preempt_check+0x1c/0x20 lib/smp_processor_id.c:62
CPU: 1 PID: 8770 Comm: syz-executor2 Not tainted 4.4.120-gd63fdf6 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 c486f509ccc6ecef ffff8801c87076b8 ffffffff81d0408d
 0000000000000001 ffffffff839fe5a0 ffffffff83d0be20 ffff8801c2138000
 0000000000000003 ffff8801c87076f8 ffffffff81d63fe4 ffff8801c8707710
Call Trace:
 [<ffffffff81d0408d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0408d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81d63fe4>] check_preemption_disabled+0x1d4/0x200 lib/smp_processor_id.c:46
 [<ffffffff81d6404c>] __this_cpu_preempt_check+0x1c/0x20 lib/smp_processor_id.c:62
 [<ffffffff832e2f08>] ipcomp_alloc_tfms net/xfrm/xfrm_ipcomp.c:286 [inline]
 [<ffffffff832e2f08>] ipcomp_init_state+0x188/0x980 net/xfrm/xfrm_ipcomp.c:363
 [<ffffffff833eb945>] ipcomp6_init_state+0xb5/0x820 net/ipv6/ipcomp6.c:165
 [<ffffffff832c1817>] __xfrm_init_state+0x3e7/0xb30 net/xfrm/xfrm_state.c:2058
 [<ffffffff832c1f7a>] xfrm_init_state+0x1a/0x20 net/xfrm/xfrm_state.c:2084
 [<ffffffff8344681b>] pfkey_msg2xfrm_state net/key/af_key.c:1289 [inline]
 [<ffffffff8344681b>] pfkey_add+0x1fbb/0x3490 net/key/af_key.c:1506
 [<ffffffff8344a45b>] pfkey_process+0x68b/0x750 net/key/af_key.c:2834
 [<ffffffff8344bcb9>] pfkey_sendmsg+0x3a9/0x760 net/key/af_key.c:3678
 [<ffffffff82deba6a>] sock_sendmsg_nosec net/socket.c:625 [inline]
 [<ffffffff82deba6a>] sock_sendmsg+0xca/0x110 net/socket.c:635
 [<ffffffff82ded641>] ___sys_sendmsg+0x6c1/0x7c0 net/socket.c:1962
 [<ffffffff82def693>] __sys_sendmsg+0xd3/0x190 net/socket.c:1996
 [<ffffffff82def77d>] SYSC_sendmsg net/socket.c:2007 [inline]
 [<ffffffff82def77d>] SyS_sendmsg+0x2d/0x50 net/socket.c:2003
 [<ffffffff8377395f>] entry_SYSCALL_64_fastpath+0x1c/0x98
BUG: using __this_cpu_read() in preemptible [00000000] code: syz-executor2/8816
caller is __this_cpu_preempt_check+0x1c/0x20 lib/smp_processor_id.c:62
CPU: 1 PID: 8816 Comm: syz-executor2 Not tainted 4.4.120-gd63fdf6 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 ff41055393df6584 ffff8801d95b76b8 ffffffff81d0408d
 0000000000000001 ffffffff839fe5a0 ffffffff83d0be20 ffff8800adc14800
 0000000000000003 ffff8801d95b76f8 ffffffff81d63fe4 ffff8801d95b7710
Call Trace:
 [<ffffffff81d0408d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0408d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81d63fe4>] check_preemption_disabled+0x1d4/0x200 lib/smp_processor_id.c:46
 [<ffffffff81d6404c>] __this_cpu_preempt_check+0x1c/0x20 lib/smp_processor_id.c:62
 [<ffffffff832e2f08>] ipcomp_alloc_tfms net/xfrm/xfrm_ipcomp.c:286 [inline]
 [<ffffffff832e2f08>] ipcomp_init_state+0x188/0x980 net/xfrm/xfrm_ipcomp.c:363
 [<ffffffff833eb945>] ipcomp6_init_state+0xb5/0x820 net/ipv6/ipcomp6.c:165
 [<ffffffff832c1817>] __xfrm_init_state+0x3e7/0xb30 net/xfrm/xfrm_state.c:2058
 [<ffffffff832c1f7a>] xfrm_init_state+0x1a/0x20 net/xfrm/xfrm_state.c:2084
 [<ffffffff8344681b>] pfkey_msg2xfrm_state net/key/af_key.c:1289 [inline]
 [<ffffffff8344681b>] pfkey_add+0x1fbb/0x3490 net/key/af_key.c:1506
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=32079 sclass=netlink_route_socket
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=32079 sclass=netlink_route_socket
 [<ffffffff8344a45b>] pfkey_process+0x68b/0x750 net/key/af_key.c:2834
 [<ffffffff8344bcb9>] pfkey_sendmsg+0x3a9/0x760 net/key/af_key.c:3678
 [<ffffffff82deba6a>] sock_sendmsg_nosec net/socket.c:625 [inline]
 [<ffffffff82deba6a>] sock_sendmsg+0xca/0x110 net/socket.c:635
 [<ffffffff82ded641>] ___sys_sendmsg+0x6c1/0x7c0 net/socket.c:1962
 [<ffffffff82def693>] __sys_sendmsg+0xd3/0x190 net/socket.c:1996
 [<ffffffff82def77d>] SYSC_sendmsg net/socket.c:2007 [inline]
 [<ffffffff82def77d>] SyS_sendmsg+0x2d/0x50 net/socket.c:2003
 [<ffffffff8377395f>] entry_SYSCALL_64_fastpath+0x1c/0x98
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=13379 sclass=netlink_route_socket
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=13379 sclass=netlink_route_socket
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=58131 sclass=netlink_route_socket
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=58131 sclass=netlink_route_socket
nla_parse: 103 callbacks suppressed
netlink: 2 bytes leftover after parsing attributes in process `syz-executor6'.
netlink: 2 bytes leftover after parsing attributes in process `syz-executor0'.
netlink: 2 bytes leftover after parsing attributes in process `syz-executor0'.
audit: type=1400 audit(1521624076.662:29): avc:  denied  { bind } for  pid=9182 comm="syz-executor2" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1
netlink: 2 bytes leftover after parsing attributes in process `syz-executor1'.
netlink: 2 bytes leftover after parsing attributes in process `syz-executor6'.
netlink: 2 bytes leftover after parsing attributes in process `syz-executor1'.
audit: type=1400 audit(1521624076.752:30): avc:  denied  { bind } for  pid=9182 comm="syz-executor2" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1
audit: type=1400 audit(1521624076.862:31): avc:  denied  { setattr } for  pid=9228 comm="syz-executor7" path="/proc/622/attr/current" dev="proc" ino=21112 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=file permissive=1
audit: type=1400 audit(1521624076.912:32): avc:  denied  { setattr } for  pid=9228 comm="syz-executor7" path="/proc/622/attr/current" dev="proc" ino=21112 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=file permissive=1
netlink: 2 bytes leftover after parsing attributes in process `syz-executor6'.