============================= WARNING: suspicious RCU usage 4.15.0-rc1-mm1+ #29 Not tainted ----------------------------- ./include/trace/events/kmem.h:142 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syzkaller250371/3084: #0: (sk_lock-AF_ALG){+.+.}, at: [<000000003c6ecc3b>] lock_sock include/net/sock.h:1467 [inline] #0: (sk_lock-AF_ALG){+.+.}, at: [<000000003c6ecc3b>] af_alg_wait_for_data+0x2f2/0x650 crypto/af_alg.c:768 stack backtrace: CPU: 1 PID: 3084 Comm: syzkaller250371 Not tainted 4.15.0-rc1-mm1+ #29 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 lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4675 trace_kfree include/trace/events/kmem.h:137 [inline] kfree+0x20a/0x250 mm/slab.c:3797 blkcipher_walk_done+0x72b/0xde0 crypto/blkcipher.c:139 encrypt+0x50a/0xaf0 crypto/salsa20_generic.c:208 skcipher_crypt_blkcipher crypto/skcipher.c:622 [inline] skcipher_decrypt_blkcipher+0x213/0x310 crypto/skcipher.c:640 crypto_skcipher_decrypt include/crypto/skcipher.h:463 [inline] _skcipher_recvmsg crypto/algif_skcipher.c:144 [inline] skcipher_recvmsg+0xa54/0xf20 crypto/algif_skcipher.c:165 sock_recvmsg_nosec net/socket.c:805 [inline] sock_recvmsg+0xc9/0x110 net/socket.c:812 ___sys_recvmsg+0x29b/0x630 net/socket.c:2207 __sys_recvmsg+0xe2/0x210 net/socket.c:2252 SYSC_recvmsg net/socket.c:2264 [inline] SyS_recvmsg+0x2d/0x50 net/socket.c:2259 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x43fe99 RSP: 002b:00007ffeb42ebd38 EFLAGS: 00000207 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fe99 RDX: 0000000000000000 RSI: 0000000020d63fc8 RDI: 0000000000000004 RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000207 R12: 0000000000401800 R13: 0000000000401890 R14: 0000000000000000 R15: 0000000000000000 BUG: unable to handle kernel NULL pointer dereference at 000000002fd59d9e IP: virt_to_cache mm/slab.c:400 [inline] IP: kfree+0xb2/0x250 mm/slab.c:3803 PGD 1cb6a6067 P4D 1cb6a6067 PUD 1cb689067 PMD 0 Oops: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 3084 Comm: syzkaller250371 Not tainted 4.15.0-rc1-mm1+ #29 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: 00000000b849d719 task.stack: 00000000d989d873 RIP: 0010:virt_to_cache mm/slab.c:400 [inline] RIP: 0010:kfree+0xb2/0x250 mm/slab.c:3803 RSP: 0018:ffff8801cb587780 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff8801cb587948 RCX: ffffffffffffffff RDX: ffffea00072d61c0 RSI: 0000000000000000 RDI: ffff8801cb587948 RBP: ffff8801cb5877a0 R08: 1ffff100396b0ea2 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000282 R13: 0000000000000000 R14: ffff8801cb587948 R15: ffff8801cb5878b0 FS: 0000000001d0a880(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000074 CR3: 00000001cc2b6000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: blkcipher_walk_done+0x72b/0xde0 crypto/blkcipher.c:139 encrypt+0x50a/0xaf0 crypto/salsa20_generic.c:208 skcipher_crypt_blkcipher crypto/skcipher.c:622 [inline] skcipher_decrypt_blkcipher+0x213/0x310 crypto/skcipher.c:640 crypto_skcipher_decrypt include/crypto/skcipher.h:463 [inline] _skcipher_recvmsg crypto/algif_skcipher.c:144 [inline] skcipher_recvmsg+0xa54/0xf20 crypto/algif_skcipher.c:165 sock_recvmsg_nosec net/socket.c:805 [inline] sock_recvmsg+0xc9/0x110 net/socket.c:812 ___sys_recvmsg+0x29b/0x630 net/socket.c:2207 __sys_recvmsg+0xe2/0x210 net/socket.c:2252 SYSC_recvmsg net/socket.c:2264 [inline] SyS_recvmsg+0x2d/0x50 net/socket.c:2259 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x43fe99 RSP: 002b:00007ffeb42ebd38 EFLAGS: 00000207 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fe99 RDX: 0000000000000000 RSI: 0000000020d63fc8 RDI: 0000000000000004 RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000207 R12: 0000000000401800 R13: 0000000000401890 R14: 0000000000000000 R15: 0000000000000000 Code: c2 48 b8 00 00 00 00 00 ea ff ff 48 89 df 48 c1 ea 0c 48 c1 e2 06 48 01 c2 48 8b 42 20 48 8d 48 ff a8 01 48 0f 45 d1 4c 8b 6a 30 <49> 63 75 74 e8 25 52 af ff 48 89 de 4c 89 ef 4c 8b 75 08 e8 76 RIP: virt_to_cache mm/slab.c:400 [inline] RSP: ffff8801cb587780 RIP: kfree+0xb2/0x250 mm/slab.c:3803 RSP: ffff8801cb587780 CR2: 0000000000000074 ---[ end trace fab8f246a3feffa1 ]---