============================= WARNING: suspicious RCU usage BUG: unable to handle kernel NULL pointer dereference at 0000000000000074 IP: virt_to_cache mm/slab.c:400 [inline] IP: kfree+0xb2/0x250 mm/slab.c:3803 PGD 1cd5ea067 P4D 1cd5ea067 PUD 1bff75067 PMD 0 Oops: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 7748 Comm: syz-executor2 Not tainted 4.15.0-rc1-mm1+ #27 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801c7ace440 task.stack: ffff8801cc018000 RIP: 0010:virt_to_cache mm/slab.c:400 [inline] RIP: 0010:kfree+0xb2/0x250 mm/slab.c:3803 RSP: 0018:ffff8801cc01f780 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff8801cc01f948 RCX: ffffffffffffffff RDX: ffffea00073007c0 RSI: 0000000000000000 RDI: ffff8801cc01f948 RBP: ffff8801cc01f7a0 R08: ffff8801d1b77740 R09: ffff8801db1ade80 R10: ffff8801cc01f950 R11: 0000000000000108 R12: 0000000000000286 R13: 0000000000000000 R14: ffff8801cc01f948 R15: ffff8801cc01f8b0 FS: 00007f9d8ef6e700(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000074 CR3: 00000001c514d000 CR4: 00000000001426e0 Call Trace: blkcipher_walk_done+0x72b/0xde0 crypto/blkcipher.c:139 encrypt+0x20e/0x540 arch/x86/crypto/salsa20_glue.c:79 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: 0033:0x4529d9 RSP: 002b:00007f9d8ef6dc58 EFLAGS: 00000212 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 00000000007580d8 RCX: 00000000004529d9 RDX: 0000000000002021 RSI: 0000000020b2dfc8 RDI: 0000000000000016 RBP: 000000000000039b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f2728 R13: 00000000ffffffff R14: 00007f9d8ef6e6d4 R15: 0000000000000019 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 f5 55 af ff 48 89 de 4c 89 ef 4c 8b 75 08 e8 76 RIP: virt_to_cache mm/slab.c:400 [inline] RSP: ffff8801cc01f780 RIP: kfree+0xb2/0x250 mm/slab.c:3803 RSP: ffff8801cc01f780 CR2: 0000000000000074 ---[ end trace 20dd52f514dc637f ]---