On Thu, Nov 30, 2017 at 11:55:00AM -0800, syzbot wrote: > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x257 lib/dump_stack.c:53 > ___might_sleep+0x2b2/0x470 kernel/sched/core.c:6060 > __might_sleep+0x95/0x190 kernel/sched/core.c:6013 > __do_page_fault+0x350/0xc90 arch/x86/mm/fault.c:1372 > do_page_fault+0xee/0x720 arch/x86/mm/fault.c:1504 > page_fault+0x22/0x30 arch/x86/entry/entry_64.S:1094 > RIP: 0010:virt_to_cache mm/slab.c:400 [inline] > RIP: 0010:kfree+0xb2/0x250 mm/slab.c:3802 > RSP: 0018:ffff8801cc82f780 EFLAGS: 00010046 > RAX: 0000000000000000 RBX: ffff8801cc82f948 RCX: ffffffffffffffff > RDX: ffffea0007320bc0 RSI: 0000000000000000 RDI: ffff8801cc82f948 > RBP: ffff8801cc82f7a0 R08: ffffed003a54e4dc R09: 0000000000000000 > R10: 0000000000000001 R11: ffffed003a54e4db R12: 0000000000000286 > R13: 0000000000000000 R14: ffff8801cc82f948 R15: ffff8801cc82f8b0 > 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
Yet another duplicate of the Salsa20 bug: #syz dup: WARNING: suspicious RCU usage (3) Looks like this one was incorrectly attributed to x86 rather than crypto? kfree() is being called with preempt_count corrupted *and* with an uninitialized pointer, so it can cause quite a few different problems... Eric
