Am Dienstag, 28. November 2017, 18:24:01 CET schrieb syzbot: Hi, > Hello, > > syzkaller hit the following crash on > 1ea8d039f9edcfefb20d8ddfe136930f6e551529 > git://git.cmpxchg.org/linux-mmots.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached. > C reproducer is attached > syzkaller reproducer is attached. See https://goo.gl/kgGztJ > for information about syzkaller reproducers > > > kasan: CONFIG_KASAN_INLINE enabled > kasan: GPF could be caused by NULL-ptr deref or user memory access > general protection fault: 0000 [#1] SMP KASAN > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 0 PID: 17658 Comm: syzkaller625686 Not tainted 4.14.0-mm1+ #25 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > task: ffff8801c734e280 task.stack: ffff8801c5f10000 > RIP: 0010:scatterwalk_start include/crypto/scatterwalk.h:86 [inline] > RIP: 0010:scatterwalk_pagedone include/crypto/scatterwalk.h:111 [inline] > RIP: 0010:scatterwalk_copychunks+0x337/0x480 crypto/scatterwalk.c:55 > RSP: 0018:ffff8801c5f175c8 EFLAGS: 00010202 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff82502da9 > RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000008 > RBP: ffff8801c5f17628 R08: ffff8801c5f177c0 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: ffff8801c5f177c0 R14: dffffc0000000000 R15: 0000000000000000 > FS: 00007f8ce5e49700(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000020284000 CR3: 00000001ce96c000 CR4: 00000000001406f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > blkcipher_next_slow crypto/blkcipher.c:175 [inline] > blkcipher_walk_next+0xca0/0x13d0 crypto/blkcipher.c:255 > blkcipher_walk_first+0x261/0x570 crypto/blkcipher.c:346 > blkcipher_walk_virt+0x219/0x2a0 crypto/blkcipher.c:308 > skcipher_null_crypt+0x10e/0x2d0 crypto/crypto_null.c:85 > skcipher_crypt_blkcipher crypto/skcipher.c:619 [inline] > skcipher_encrypt_blkcipher+0x213/0x310 crypto/skcipher.c:628 > crypto_skcipher_encrypt include/crypto/skcipher.h:445 [inline] > crypto_aead_copy_sgl crypto/algif_aead.c:90 [inline] > _aead_recvmsg crypto/algif_aead.c:228 [inline] > aead_recvmsg+0xc96/0x1970 crypto/algif_aead.c:313 > aead_recvmsg_nokey+0x60/0x80 crypto/algif_aead.c:431 > 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 After compiling the kernel with the given config and execute the test app for now 10 minutes, I am unable to reproduce the issue. Ok, granted, I use the patches https://git.kernel.org/pub/scm/linux/kernel/ git/herbert/crypto-2.6.git/commit/?id=7d2c3f54e6f646887d019faa45f35d6fe9fe82ce and https://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6.git/ commit/?id=8e1fa89aa8bc2870009b4486644e4a58f2e2a4f5 Do you have an idea what I need to change to reproduce the issue? Note, my test system is a KVM/QEMU 64 bit virtual machine. Thanks. Ciao Stephan