======================================================
[ INFO: possible circular locking dependency detected ]
4.4.174+ #4 Not tainted
-------------------------------------------------------
syz-executor.1/5414 is trying to acquire lock:
 (rtnl_mutex){+.+.+.}, at: [<ffffffff8226e537>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70

but task is already holding lock:
 (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff825fd4aa>] lock_sock include/net/sock.h:1497 [inline]
 (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff825fd4aa>] do_ipv6_setsockopt.isra.0+0x28a/0x30c0 net/ipv6/ipv6_sockglue.c:166

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

       [<ffffffff81205f6e>] lock_acquire+0x15e/0x450 kernel/locking/lockdep.c:3592
       [<ffffffff821e4f06>] lock_sock_nested+0xc6/0x120 net/core/sock.c:2463
       [<ffffffff823d7370>] lock_sock include/net/sock.h:1497 [inline]
       [<ffffffff823d7370>] do_ip_setsockopt.isra.0+0x100/0x33a0 net/ipv4/ip_sockglue.c:625
       [<ffffffff823da64b>] ip_setsockopt+0x3b/0xa0 net/ipv4/ip_sockglue.c:1218
       [<ffffffff824803be>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2162
       [<ffffffff82600384>] ipv6_setsockopt+0xa4/0x140 net/ipv6/ipv6_sockglue.c:899
       [<ffffffff823f782a>] tcp_setsockopt net/ipv4/tcp.c:2643 [inline]
       [<ffffffff823f782a>] tcp_setsockopt+0x8a/0xe0 net/ipv4/tcp.c:2637
       [<ffffffff821def2a>] sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2663
       [<ffffffff821dcb59>] SYSC_setsockopt net/socket.c:1780 [inline]
       [<ffffffff821dcb59>] SyS_setsockopt+0x159/0x240 net/socket.c:1759
       [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a

       [<ffffffff81202d86>] check_prev_add kernel/locking/lockdep.c:1853 [inline]
       [<ffffffff81202d86>] check_prevs_add kernel/locking/lockdep.c:1958 [inline]
       [<ffffffff81202d86>] validate_chain kernel/locking/lockdep.c:2144 [inline]
       [<ffffffff81202d86>] __lock_acquire+0x37d6/0x4f50 kernel/locking/lockdep.c:3213
       [<ffffffff81205f6e>] lock_acquire+0x15e/0x450 kernel/locking/lockdep.c:3592
       [<ffffffff8270c191>] __mutex_lock_common kernel/locking/mutex.c:521 [inline]
       [<ffffffff8270c191>] mutex_lock_nested+0xc1/0xb80 kernel/locking/mutex.c:621
       [<ffffffff8226e537>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
       [<ffffffff826369ee>] ipv6_sock_mc_close+0x10e/0x350 net/ipv6/mcast.c:288
       [<ffffffff825fedf1>] do_ipv6_setsockopt.isra.0+0x1bd1/0x30c0 net/ipv6/ipv6_sockglue.c:202
       [<ffffffff826003ba>] ipv6_setsockopt+0xda/0x140 net/ipv6/ipv6_sockglue.c:904
       [<ffffffff82614abe>] udpv6_setsockopt+0x4e/0x90 net/ipv6/udp.c:1436
       [<ffffffff821def2a>] sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2663
       [<ffffffff821dcb59>] SYSC_setsockopt net/socket.c:1780 [inline]
       [<ffffffff821dcb59>] SyS_setsockopt+0x159/0x240 net/socket.c:1759
       [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sk_lock-AF_INET6);
                               lock(rtnl_mutex);
                               lock(sk_lock-AF_INET6);
  lock(rtnl_mutex);

 *** DEADLOCK ***

1 lock held by syz-executor.1/5414:
 #0:  (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff825fd4aa>] lock_sock include/net/sock.h:1497 [inline]
 #0:  (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff825fd4aa>] do_ipv6_setsockopt.isra.0+0x28a/0x30c0 net/ipv6/ipv6_sockglue.c:166

stack backtrace:
CPU: 1 PID: 5414 Comm: syz-executor.1 Not tainted 4.4.174+ #4
 0000000000000000 2974928c970e59b0 ffff8800a6d775c0 ffffffff81aad1a1
 ffffffff84057a80 ffff8801d3832f80 ffffffff83a8dd00 ffffffff83acc910
 ffffffff83a8dd00 ffff8800a6d77610 ffffffff813abcda ffff8800a6d776f0
Call Trace:
 [<ffffffff81aad1a1>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81aad1a1>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<ffffffff813abcda>] print_circular_bug.cold+0x2f7/0x44e kernel/locking/lockdep.c:1226
 [<ffffffff81202d86>] check_prev_add kernel/locking/lockdep.c:1853 [inline]
 [<ffffffff81202d86>] check_prevs_add kernel/locking/lockdep.c:1958 [inline]
 [<ffffffff81202d86>] validate_chain kernel/locking/lockdep.c:2144 [inline]
 [<ffffffff81202d86>] __lock_acquire+0x37d6/0x4f50 kernel/locking/lockdep.c:3213
 [<ffffffff81205f6e>] lock_acquire+0x15e/0x450 kernel/locking/lockdep.c:3592
 [<ffffffff8270c191>] __mutex_lock_common kernel/locking/mutex.c:521 [inline]
 [<ffffffff8270c191>] mutex_lock_nested+0xc1/0xb80 kernel/locking/mutex.c:621
 [<ffffffff8226e537>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 [<ffffffff826369ee>] ipv6_sock_mc_close+0x10e/0x350 net/ipv6/mcast.c:288
 [<ffffffff825fedf1>] do_ipv6_setsockopt.isra.0+0x1bd1/0x30c0 net/ipv6/ipv6_sockglue.c:202
 [<ffffffff826003ba>] ipv6_setsockopt+0xda/0x140 net/ipv6/ipv6_sockglue.c:904
 [<ffffffff82614abe>] udpv6_setsockopt+0x4e/0x90 net/ipv6/udp.c:1436
 [<ffffffff821def2a>] sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2663
 [<ffffffff821dcb59>] SYSC_setsockopt net/socket.c:1780 [inline]
 [<ffffffff821dcb59>] SyS_setsockopt+0x159/0x240 net/socket.c:1759
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
vmalloc: allocation failure: 17179869176 bytes
syz-executor.1: page allocation failure: order:0, mode:0x24000c2
CPU: 1 PID: 5443 Comm: syz-executor.1 Not tainted 4.4.174+ #4
 0000000000000000 6bdfb700819906c9 ffff8800b8c07818 ffffffff81aad1a1
 1ffff10017180f06 ffff8800a716af80 00000000024000c2 0000000000000000
 ffffffff82895080 ffff8800b8c07928 ffffffff8148c0cb ffff880100000001
Call Trace:
 [<ffffffff81aad1a1>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81aad1a1>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<ffffffff8148c0cb>] warn_alloc_failed.cold+0x78/0x99 mm/page_alloc.c:2757
 [<ffffffff8145fb65>] __vmalloc_node_range mm/vmalloc.c:1693 [inline]
 [<ffffffff8145fb65>] __vmalloc_node_range+0x365/0x650 mm/vmalloc.c:1654
 [<ffffffff8146031c>] __vmalloc_node mm/vmalloc.c:1716 [inline]
 [<ffffffff8146031c>] __vmalloc_node_flags mm/vmalloc.c:1730 [inline]
 [<ffffffff8146031c>] vmalloc+0x5c/0x70 mm/vmalloc.c:1745
 [<ffffffff8236da74>] xt_alloc_entry_offsets+0x44/0x60 net/netfilter/x_tables.c:757
 [<ffffffff825299a7>] translate_table+0x2c7/0x1c00 net/ipv4/netfilter/arp_tables.c:654
 [<ffffffff8252febd>] do_replace.isra.0+0x1cd/0x470 net/ipv4/netfilter/arp_tables.c:1116
 [<ffffffff825303b2>] do_arpt_set_ctl+0x102/0x150 net/ipv4/netfilter/arp_tables.c:1620
 [<ffffffff822fcfad>] nf_sockopt net/netfilter/nf_sockopt.c:105 [inline]
 [<ffffffff822fcfad>] nf_setsockopt+0x6d/0xc0 net/netfilter/nf_sockopt.c:114
 [<ffffffff823da69a>] ip_setsockopt net/ipv4/ip_sockglue.c:1225 [inline]
 [<ffffffff823da69a>] ip_setsockopt+0x8a/0xa0 net/ipv4/ip_sockglue.c:1210
 [<ffffffff823f782a>] tcp_setsockopt net/ipv4/tcp.c:2643 [inline]
 [<ffffffff823f782a>] tcp_setsockopt+0x8a/0xe0 net/ipv4/tcp.c:2637
 [<ffffffff821def2a>] sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2663
 [<ffffffff821dcb59>] SYSC_setsockopt net/socket.c:1780 [inline]
 [<ffffffff821dcb59>] SyS_setsockopt+0x159/0x240 net/socket.c:1759
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
Mem-Info:
active_anon:44760 inactive_anon:4263 isolated_anon:0
 active_file:4561 inactive_file:10819 isolated_file:0
 unevictable:0 dirty:34 writeback:0 unstable:0
 slab_reclaimable:5118 slab_unreclaimable:59286
 mapped:58740 shmem:4143 pagetables:2727 bounce:0
 free:1453271 free_pcp:431 free_cma:0
DMA32 free:2656584kB min:4696kB low:5868kB high:7044kB active_anon:78640kB inactive_anon:11980kB active_file:8124kB inactive_file:19968kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:3145324kB managed:3021976kB mlocked:0kB dirty:24kB writeback:0kB mapped:107904kB shmem:11776kB slab_reclaimable:9748kB slab_unreclaimable:106972kB kernel_stack:2912kB pagetables:4740kB unstable:0kB bounce:0kB free_pcp:484kB local_pcp:236kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 3504 3504
Normal free:3151548kB min:5580kB low:6972kB high:8368kB active_anon:100400kB inactive_anon:9772kB active_file:10120kB inactive_file:23308kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:4718592kB managed:3588764kB mlocked:0kB dirty:112kB writeback:0kB mapped:126908kB shmem:9532kB slab_reclaimable:10724kB slab_unreclaimable:130516kB kernel_stack:4224kB pagetables:6168kB unstable:0kB bounce:0kB free_pcp:932kB local_pcp:208kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 0 0
DMA32: 170*4kB (UME) 1022*8kB (UE) 886*16kB (UE) 22*32kB (UME) 82*64kB (UME) 40*128kB (UM) 17*256kB (UME) 20*512kB (UME) 20*1024kB (UME) 12*2048kB (UM) 625*4096kB (UM) = 2653752kB
Normal: 12*4kB (UE) 1035*8kB (UE) 1107*16kB (UME) 38*32kB (UME) 30*64kB (UE) 37*128kB (UM) 4*256kB (U) 17*512kB (UME) 18*1024kB (UM) 11*2048kB (UM) 747*4096kB (UM) = 3144312kB
19522 total pagecache pages
0 pages in swap cache
Swap cache stats: add 0, delete 0, find 0/0
Free swap  = 0kB
Total swap = 0kB
1965979 pages RAM
0 pages HighMem/MovableOnly
313294 pages reserved
vmalloc: allocation failure: 17179869176 bytes
syz-executor.1: page allocation failure: order:0, mode:0x24000c2
CPU: 0 PID: 5487 Comm: syz-executor.1 Not tainted 4.4.174+ #4
 0000000000000000 e99bc0c0c73bab31 ffff8801d3227818 ffffffff81aad1a1
 1ffff1003a644f06 ffff8800b74f97c0 00000000024000c2 0000000000000000
 ffffffff82895080 ffff8801d3227928 ffffffff8148c0cb 0000000000000001
Call Trace:
 [<ffffffff81aad1a1>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81aad1a1>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<ffffffff8148c0cb>] warn_alloc_failed.cold+0x78/0x99 mm/page_alloc.c:2757
 [<ffffffff8145fb65>] __vmalloc_node_range mm/vmalloc.c:1693 [inline]
 [<ffffffff8145fb65>] __vmalloc_node_range+0x365/0x650 mm/vmalloc.c:1654
 [<ffffffff8146031c>] __vmalloc_node mm/vmalloc.c:1716 [inline]
 [<ffffffff8146031c>] __vmalloc_node_flags mm/vmalloc.c:1730 [inline]
 [<ffffffff8146031c>] vmalloc+0x5c/0x70 mm/vmalloc.c:1745
 [<ffffffff8236da74>] xt_alloc_entry_offsets+0x44/0x60 net/netfilter/x_tables.c:757
 [<ffffffff825299a7>] translate_table+0x2c7/0x1c00 net/ipv4/netfilter/arp_tables.c:654
 [<ffffffff8252febd>] do_replace.isra.0+0x1cd/0x470 net/ipv4/netfilter/arp_tables.c:1116
 [<ffffffff825303b2>] do_arpt_set_ctl+0x102/0x150 net/ipv4/netfilter/arp_tables.c:1620
 [<ffffffff822fcfad>] nf_sockopt net/netfilter/nf_sockopt.c:105 [inline]
 [<ffffffff822fcfad>] nf_setsockopt+0x6d/0xc0 net/netfilter/nf_sockopt.c:114
 [<ffffffff823da69a>] ip_setsockopt net/ipv4/ip_sockglue.c:1225 [inline]
 [<ffffffff823da69a>] ip_setsockopt+0x8a/0xa0 net/ipv4/ip_sockglue.c:1210
 [<ffffffff823f782a>] tcp_setsockopt net/ipv4/tcp.c:2643 [inline]
 [<ffffffff823f782a>] tcp_setsockopt+0x8a/0xe0 net/ipv4/tcp.c:2637
 [<ffffffff821def2a>] sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2663
 [<ffffffff821dcb59>] SYSC_setsockopt net/socket.c:1780 [inline]
 [<ffffffff821dcb59>] SyS_setsockopt+0x159/0x240 net/socket.c:1759
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
Mem-Info:
active_anon:44696 inactive_anon:4266 isolated_anon:0
 active_file:4563 inactive_file:10818 isolated_file:0
 unevictable:0 dirty:40 writeback:0 unstable:0
 slab_reclaimable:5134 slab_unreclaimable:59111
 mapped:58703 shmem:4143 pagetables:2674 bounce:0
 free:1453990 free_pcp:173 free_cma:0
DMA32 free:2661672kB min:4696kB low:5868kB high:7044kB active_anon:78528kB inactive_anon:7284kB active_file:8132kB inactive_file:19964kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:3145324kB managed:3021976kB mlocked:0kB dirty:28kB writeback:0kB mapped:107904kB shmem:7040kB slab_reclaimable:9748kB slab_unreclaimable:106784kB kernel_stack:2656kB pagetables:4780kB unstable:0kB bounce:0kB free_pcp:272kB local_pcp:52kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 3504 3504
Normal free:3154288kB min:5580kB low:6972kB high:8368kB active_anon:100256kB inactive_anon:9780kB active_file:10120kB inactive_file:23308kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:4718592kB managed:3588764kB mlocked:0kB dirty:132kB writeback:0kB mapped:126908kB shmem:9532kB slab_reclaimable:10788kB slab_unreclaimable:129660kB kernel_stack:4128kB pagetables:5916kB unstable:0kB bounce:0kB free_pcp:420kB local_pcp:148kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 0 0
DMA32: 132*4kB (UME) 1111*8kB (UME) 952*16kB (UME) 68*32kB (UME) 113*64kB (UME) 57*128kB (UM) 18*256kB (UME) 19*512kB (UME) 21*1024kB (UME) 12*2048kB (UM) 625*4096kB (UM) = 2661768kB
Normal: 132*4kB (UME) 1222*8kB (UME) 1171*16kB (UME) 98*32kB (UME) 48*64kB (UME) 58*128kB (UM) 7*256kB (UM) 18*512kB (UME) 18*1024kB (UM) 11*2048kB (UM) 747*4096kB (UM) = 3154352kB
19525 total pagecache pages
0 pages in swap cache
Swap cache stats: add 0, delete 0, find 0/0
Free swap  = 0kB
Total swap = 0kB
1965979 pages RAM
0 pages HighMem/MovableOnly
313294 pages reserved
vmalloc: allocation failure: 17179869176 bytes
syz-executor.1: page allocation failure: order:0, mode:0x24000c2
CPU: 1 PID: 5504 Comm: syz-executor.1 Not tainted 4.4.174+ #4
 0000000000000000 377d175a81ae8bde ffff8800b646f818 ffffffff81aad1a1
 1ffff10016c8df06 ffff8800b6424740 00000000024000c2 0000000000000000
 ffffffff82895080 ffff8800b646f928 ffffffff8148c0cb ffff880000000001
Call Trace:
 [<ffffffff81aad1a1>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81aad1a1>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<ffffffff8148c0cb>] warn_alloc_failed.cold+0x78/0x99 mm/page_alloc.c:2757
 [<ffffffff8145fb65>] __vmalloc_node_range mm/vmalloc.c:1693 [inline]
 [<ffffffff8145fb65>] __vmalloc_node_range+0x365/0x650 mm/vmalloc.c:1654
 [<ffffffff8146031c>] __vmalloc_node mm/vmalloc.c:1716 [inline]
 [<ffffffff8146031c>] __vmalloc_node_flags mm/vmalloc.c:1730 [inline]
 [<ffffffff8146031c>] vmalloc+0x5c/0x70 mm/vmalloc.c:1745
 [<ffffffff8236da74>] xt_alloc_entry_offsets+0x44/0x60 net/netfilter/x_tables.c:757
 [<ffffffff825299a7>] translate_table+0x2c7/0x1c00 net/ipv4/netfilter/arp_tables.c:654
 [<ffffffff8252febd>] do_replace.isra.0+0x1cd/0x470 net/ipv4/netfilter/arp_tables.c:1116
 [<ffffffff825303b2>] do_arpt_set_ctl+0x102/0x150 net/ipv4/netfilter/arp_tables.c:1620
 [<ffffffff822fcfad>] nf_sockopt net/netfilter/nf_sockopt.c:105 [inline]
 [<ffffffff822fcfad>] nf_setsockopt+0x6d/0xc0 net/netfilter/nf_sockopt.c:114
 [<ffffffff823da69a>] ip_setsockopt net/ipv4/ip_sockglue.c:1225 [inline]
 [<ffffffff823da69a>] ip_setsockopt+0x8a/0xa0 net/ipv4/ip_sockglue.c:1210
 [<ffffffff823f782a>] tcp_setsockopt net/ipv4/tcp.c:2643 [inline]
 [<ffffffff823f782a>] tcp_setsockopt+0x8a/0xe0 net/ipv4/tcp.c:2637
 [<ffffffff821def2a>] sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2663
 [<ffffffff821dcb59>] SYSC_setsockopt net/socket.c:1780 [inline]
 [<ffffffff821dcb59>] SyS_setsockopt+0x159/0x240 net/socket.c:1759
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
Mem-Info:
active_anon:44696 inactive_anon:4267 isolated_anon:0
 active_file:4569 inactive_file:10818 isolated_file:0
 unevictable:0 dirty:53 writeback:0 unstable:0
 slab_reclaimable:5158 slab_unreclaimable:58934
 mapped:58703 shmem:4143 pagetables:2674 bounce:0
 free:1453629 free_pcp:541 free_cma:0
DMA32 free:2660928kB min:4696kB low:5868kB high:7044kB active_anon:78480kB inactive_anon:7304kB active_file:8132kB inactive_file:19964kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:3145324kB managed:3021976kB mlocked:0kB dirty:32kB writeback:0kB mapped:107904kB shmem:7056kB slab_reclaimable:9780kB slab_unreclaimable:106532kB kernel_stack:2912kB pagetables:4816kB unstable:0kB bounce:0kB free_pcp:996kB local_pcp:384kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 3504 3504
Normal free:3153748kB min:5580kB low:6972kB high:8368kB active_anon:100304kB inactive_anon:9764kB active_file:10144kB inactive_file:23308kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:4718592kB managed:3588764kB mlocked:0kB dirty:180kB writeback:0kB mapped:126908kB shmem:9516kB slab_reclaimable:10852kB slab_unreclaimable:129204kB kernel_stack:4512kB pagetables:5880kB unstable:0kB bounce:0kB free_pcp:1168kB local_pcp:544kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 0 0
DMA32: 206*4kB (UME) 1049*8kB (UME) 952*16kB (UME) 72*32kB (UME) 114*64kB (UME) 56*128kB (UM) 16*256kB (UME) 19*512kB (UME) 21*1024kB (UME) 12*2048kB (UM) 625*4096kB (UM) = 2661120kB
Normal: 301*4kB (UME) 1146*8kB (UME) 1165*16kB (UME) 105*32kB (UME) 54*64kB (UME) 56*128kB (UM) 8*256kB (UM) 16*512kB (UME) 18*1024kB (UM) 11*2048kB (UM) 747*4096kB (UM) = 3153908kB
19532 total pagecache pages
0 pages in swap cache
Swap cache stats: add 0, delete 0, find 0/0
Free swap  = 0kB
Total swap = 0kB
1965979 pages RAM
0 pages HighMem/MovableOnly
313294 pages reserved