On Wed, Nov 29, 2017 at 11:30:36AM +0100, 'Dmitry Vyukov' via syzkaller-bugs wrote: > On Wed, Nov 29, 2017 at 11:24 AM, syzbot > <bot+9f319d9f8748fecc56f23463861c56aae433413e@xxxxxxxxxxxxxxxxxxxxxxxxx> > wrote: > > Hello, > > > > syzkaller hit the following crash on > > 43570f0383d6d5879ae585e6c3cf027ba321546f > > git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master > > compiler: gcc (GCC) 7.1.1 20170620 > > .config is attached > > Raw console output is attached. > > > > Unfortunately, I don't have any reproducer for this bug yet. > > > > > > netlink: 3 bytes leftover after parsing attributes in process > > `syz-executor3'. > > device gre0 entered promiscuous mode > > 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:3802 > > PGD 1d369e067 P4D 1d369e067 PUD 1c8da0067 PMD 0 > > Oops: 0000 [#1] SMP KASAN > > Dumping ftrace buffer: > > (ftrace buffer empty) > > Modules linked in: > > CPU: 0 PID: 8031 Comm: syz-executor5 Not tainted 4.15.0-rc1+ #199 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > Google 01/01/2011 > > task: ffff8801d33f8540 task.stack: ffff8801d3b58000 > > RIP: 0010:virt_to_cache mm/slab.c:400 [inline] > > RIP: 0010:kfree+0xb2/0x250 mm/slab.c:3802 > > RSP: 0018:ffff8801d3b5f780 EFLAGS: 00010046 > > RAX: 0000000000000000 RBX: ffff8801d3b5f948 RCX: ffffffffffffffff > > RDX: ffffea00074ed7c0 RSI: 0000000000000000 RDI: ffff8801d3b5f948 > > RBP: ffff8801d3b5f7a0 R08: ffffed003a2c3b7c R09: 0000000000000000 > > R10: 0000000000000001 R11: ffffed003a2c3b7b R12: 0000000000000286 > > R13: 0000000000000000 R14: ffff8801d3b5f948 R15: ffff8801d3b5f8b0 > > FS: 00007f7f80409700(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 0000000000000074 CR3: 00000001c97a2000 CR4: 00000000001426f0 > > DR0: 0000000020001000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 > > 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 #syz dup: WARNING: suspicious RCU usage (3) All the following 5 reports appear to be the same bug in Salsa20, and I've marked them of duplicates of the first: WARNING: suspicious RCU usage (3) kernel BUG at ./include/linux/mm.h:LINE! (2) suspicious RCU usage at ./include/linux/mm.h:LINE suspicious RCU usage at ./include/trace/events/kmem.h:LINE BUG: unable to handle kernel NULL pointer dereference in kfree The bug involves an uninitialized pointer being kfreed, or an uninitialized 'struct page' being freed. Proposed fix is "crypto: salsa20 - fix blkcipher_walk API usage"
