On Tue, Dec 19, 2017 at 04:49:02AM -0800, syzbot wrote: > Hello, > > syzkaller hit the following crash on > 6084b576dca2e898f5c101baef151f7bfdbb606d > git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.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. > > > BUG: unable to handle kernel NULL pointer dereference at (null) > IP: qdisc_dev include/net/sch_generic.h:379 [inline] > IP: tc_fill_qdisc+0xc8/0x4b0 net/sched/sch_api.c:792 > PGD 1dc5d4067 P4D 1dc5d4067 PUD 1db5fa067 PMD 0 > Oops: 0000 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 0 PID: 7609 Comm: syz-executor4 Not tainted 4.15.0-rc3-next-20171214+ > #67 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:qdisc_dev include/net/sch_generic.h:379 [inline] > RIP: 0010:tc_fill_qdisc+0xc8/0x4b0 net/sched/sch_api.c:792 > RSP: 0018:ffffc90000ea38c8 EFLAGS: 00010212 > RAX: 0000000000000000 RBX: ffff880216ac3c00 RCX: ffffffff8212563c > RDX: 0000000000000a02 RSI: ffffc90004f53000 RDI: ffff8801dc6a20b0 > RBP: ffffc90000ea3970 R08: 0000000000000014 R09: ffff8801dc6a20b0 > R10: ffffc90000ea37d8 R11: 0000000000000002 R12: ffff880214161b00 > R13: ffff8801dc6a208c R14: 0000000000000000 R15: 0000000000000002 > FS: 00007f6db5bc5700(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000000 CR3: 00000001dc75a000 CR4: 00000000001426f0 > DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 > Call Trace: > tc_dump_qdisc_root+0x1f1/0x220 net/sched/sch_api.c:1474 > tc_dump_qdisc+0x1a1/0x280 net/sched/sch_api.c:1540 > netlink_dump+0x14e/0x360 net/netlink/af_netlink.c:2222 > __netlink_dump_start+0x1bb/0x210 net/netlink/af_netlink.c:2319 > netlink_dump_start include/linux/netlink.h:214 [inline] > rtnetlink_rcv_msg+0x44f/0x5d0 net/core/rtnetlink.c:4485 > netlink_rcv_skb+0x92/0x160 net/netlink/af_netlink.c:2441 > rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4540 > netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline] > netlink_unicast+0x1d4/0x290 net/netlink/af_netlink.c:1334 > netlink_sendmsg+0x345/0x470 net/netlink/af_netlink.c:1897 > sock_sendmsg_nosec net/socket.c:636 [inline] > sock_sendmsg+0x51/0x70 net/socket.c:646 > ___sys_sendmsg+0x35e/0x3b0 net/socket.c:2026 > __sys_sendmsg+0x50/0x90 net/socket.c:2060 > SYSC_sendmsg net/socket.c:2071 [inline] > SyS_sendmsg+0x2d/0x50 net/socket.c:2067 > entry_SYSCALL_64_fastpath+0x1f/0x96 > RIP: 0033:0x452a39 > RSP: 002b:00007f6db5bc4c58 EFLAGS: 00000212 ORIG_RAX: 000000000000002e > RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39 > RDX: 0000000000000000 RSI: 000000002061efc8 RDI: 000000000000001c > RBP: 0000000000000343 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f2ee8 > R13: 00000000ffffffff R14: 00007f6db5bc56d4 R15: 0000000000000000 > Code: 41 b8 14 00 00 00 4c 89 e7 e8 05 17 01 00 48 85 c0 49 89 c5 0f 84 cb > 02 00 00 e8 04 4d 19 ff 41 c7 45 10 00 00 00 00 48 8b 43 40 <48> 8b 00 8b 80 > 08 01 00 00 45 89 75 1c 41 89 45 14 8b 43 38 41 > RIP: qdisc_dev include/net/sch_generic.h:379 [inline] RSP: ffffc90000ea38c8 > RIP: tc_fill_qdisc+0xc8/0x4b0 net/sched/sch_api.c:792 RSP: ffffc90000ea38c8 > CR2: 0000000000000000 > ---[ end trace dffd1876816a33a6 ]---
Invalidating this bug since it hasn't been seen again, and it was reported while KASAN was accidentally disabled in the syzbot kconfig due to a change to the kconfig menus in linux-next (so this crash was possibly caused by slab corruption elsewhere). #syz invalid
