bisecting fixing commit since 1ca0fafd73c5268e8fc4b997094b8bb2bfe8deea
building syzkaller on 510951950dc0ee69cfdaf746061d3dbe31b49fd8
testing commit 1ca0fafd73c5268e8fc4b997094b8bb2bfe8deea with gcc (GCC) 8.1.0
kernel signature: 10d289a7e84dc5fe183082e3242ec908458b09a833bd8a798b25ec0c237f5ee2
run #0: crashed: BUG: unable to handle kernel paging request in fl_dump_key
run #1: crashed: BUG: unable to handle kernel paging request in fl_dump_key
run #2: crashed: BUG: unable to handle kernel paging request in fl_dump_key
run #3: crashed: BUG: unable to handle kernel paging request in fl_dump_key
run #4: crashed: BUG: unable to handle kernel paging request in fl_dump_key
run #5: crashed: BUG: unable to handle kernel paging request in fl_dump_key
run #6: OK
run #7: OK
run #8: OK
run #9: OK
testing current HEAD a609d0259183a841621f252e067f40f8cc25d6f6
testing commit a609d0259183a841621f252e067f40f8cc25d6f6 with gcc (GCC) 8.1.0
kernel signature: 9b11a6a9b612e6acc6b1862ff6c3c1cc97409fb89e98790861a96ecd9d722204
run #0: crashed: BUG: unable to handle kernel paging request in fl_dump_key
run #1: crashed: BUG: unable to handle kernel paging request in fl_dump_key
run #2: crashed: BUG: unable to handle kernel paging request in fl_dump_key
run #3: crashed: BUG: unable to handle kernel paging request in fl_dump_key
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
revisions tested: 2, total time: 30m42.202851495s (build: 10m34.283848876s, test: 19m34.205712815s)
the crash still happens on HEAD
commit msg: net: usb: dm9601: Add USB ID of Keenetic Plus DSL
crash: BUG: unable to handle kernel paging request in fl_dump_key
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'.
BUG: unable to handle page fault for address: ffffffffd08dddf7
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 428c067 P4D 428c067 PUD 428e067 PMD 0 
Oops: 0000 [#1] PREEMPT SMP
CPU: 1 PID: 17782 Comm: syz-executor.0 Not tainted 5.9.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:fl_dump_key+0x17/0xec0 net/sched/cls_flower.c:2781
Code: 0b e9 03 ff ff ff e8 78 43 6e 00 0f 1f 84 00 00 00 00 00 41 57 41 56 41 55 41 54 49 89 fc 55 48 89 cd 53 48 89 d3 48 83 ec 20 <8b> 11 65 48 8b 04 25 28 00 00 00 48 89 44 24 18 31 c0 85 d2 74 35
RSP: 0018:ffffc90001e37900 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffffffffd08ddc0f RCX: ffffffffd08dddf7
RDX: ffffffffd08ddc0f RSI: ffff88811194e1c0 RDI: ffff8881218dd600
RBP: ffffffffd08dddf7 R08: 0000000000000004 R09: ffff888104e4b03c
R10: 0000000000000000 R11: d5231cd2ef920d83 R12: ffff8881218dd600
R13: ffff88811194e1c0 R14: ffff888104e4b000 R15: ffff888091126000
FS:  00007f7cc359b700(0000) GS:ffff88812c100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffd08dddf7 CR3: 0000000101b58000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 fl_tmplt_dump+0x49/0xb0 net/sched/cls_flower.c:3098
 tc_chain_fill_node+0x128/0x1b0 net/sched/cls_api.c:2681
 tc_chain_notify+0x94/0x110 net/sched/cls_api.c:2707
 tc_ctl_chain+0x4bb/0x650 net/sched/cls_api.c:2893
 rtnetlink_rcv_msg+0x173/0x480 net/core/rtnetlink.c:5563
 netlink_rcv_skb+0x41/0x110 net/netlink/af_netlink.c:2470
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x19a/0x270 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x248/0x480 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0x2b/0x40 net/socket.c:671
 ____sys_sendmsg+0x1ed/0x230 net/socket.c:2353
 ___sys_sendmsg+0x77/0xb0 net/socket.c:2407
 __sys_sendmsg+0x52/0xa0 net/socket.c:2440
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cba9
Code: 8d b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 5b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f7cc359ac78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000502820 RCX: 000000000045cba9
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000009
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000a44 R14: 00000000004cd332 R15: 00007f7cc359b6d4
Modules linked in:
CR2: ffffffffd08dddf7
---[ end trace dc4a8e0a3c670f12 ]---
RIP: 0010:fl_dump_key+0x17/0xec0 net/sched/cls_flower.c:2781
Code: 0b e9 03 ff ff ff e8 78 43 6e 00 0f 1f 84 00 00 00 00 00 41 57 41 56 41 55 41 54 49 89 fc 55 48 89 cd 53 48 89 d3 48 83 ec 20 <8b> 11 65 48 8b 04 25 28 00 00 00 48 89 44 24 18 31 c0 85 d2 74 35
RSP: 0018:ffffc90001e37900 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffffffffd08ddc0f RCX: ffffffffd08dddf7
RDX: ffffffffd08ddc0f RSI: ffff88811194e1c0 RDI: ffff8881218dd600
RBP: ffffffffd08dddf7 R08: 0000000000000004 R09: ffff888104e4b03c
R10: 0000000000000000 R11: d5231cd2ef920d83 R12: ffff8881218dd600
R13: ffff88811194e1c0 R14: ffff888104e4b000 R15: ffff888091126000
FS:  00007f7cc359b700(0000) GS:ffff88812c100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffd08dddf7 CR3: 0000000101b58000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400