bisecting fixing commit since b3a9964cfa690150e49ae75ba16416ccaac3a8ba
building syzkaller on a60cb4cd840ce786236a00480e8bb1025e0c5fef
testing commit b3a9964cfa690150e49ae75ba16416ccaac3a8ba with gcc (GCC) 8.1.0
run #0: crashed: WARNING in __vunmap
run #1: OK
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
testing current HEAD 1c4e395cf7ded47f33084865cbe2357cdbe4fd07
testing commit 1c4e395cf7ded47f33084865cbe2357cdbe4fd07 with gcc (GCC) 8.1.0
run #0: crashed: WARNING in __vunmap
run #1: crashed: KASAN: use-after-free Read in ipcomp_init_state
run #2: crashed: WARNING in __vunmap
run #3: crashed: WARNING in __vunmap
run #4: crashed: WARNING in __vunmap
run #5: crashed: WARNING in __vunmap
run #6: OK
run #7: OK
run #8: OK
run #9: OK
revisions tested: 2, total time: 34m51.165883815s (build: 13m18.802849981s, test: 20m13.362821125s)
the crash still happens on HEAD
crash: WARNING in __vunmap
------------[ cut here ]------------
Trying to vfree() nonexistent vm area (000000006cd15e7f)
WARNING: CPU: 1 PID: 2809 at mm/vmalloc.c:2241 __vunmap+0x5f5/0x810 mm/vmalloc.c:2240
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 2809 Comm: syz-executor.3 Not tainted 5.4.0-rc4+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x113/0x167 lib/dump_stack.c:113
 panic+0x22a/0x4e3 kernel/panic.c:221
 __warn.cold.11+0x25/0x30 kernel/panic.c:582
 report_bug+0x1b0/0x270 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
RIP: 0010:__vunmap+0x5f5/0x810 mm/vmalloc.c:2240
Code: e9 47 ff ff ff 48 89 fe 48 c7 c7 40 c7 33 87 e8 23 1b ab ff 0f 0b e9 39 ff ff ff 4c 89 f6 48 c7 c7 a0 c7 33 87 e8 0d 1b ab ff <0f> 0b e9 23 ff ff ff 48 8b 7d d0 e8 1b 82 08 00 e9 d3 fb ff ff 48
RSP: 0018:ffff88807e65f2e0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffffc90007487000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff89fd2160
RBP: ffff88807e65f340 R08: ffffed1015d66159 R09: ffffed1015d66159
R10: ffffed1015d66158 R11: ffff8880aeb30ac7 R12: 0000000000000000
R13: 0000000000000001 R14: ffffc90007487000 R15: 0000000000000000
 __vfree+0x21/0x90 mm/vmalloc.c:2305
 vfree+0x2a/0x50 mm/vmalloc.c:2335
 ipcomp_free_scratches+0xa0/0x110 net/xfrm/xfrm_ipcomp.c:212
 ipcomp_free_data net/xfrm/xfrm_ipcomp.c:321 [inline]
 ipcomp_init_state+0x3da/0x910 net/xfrm/xfrm_ipcomp.c:373
 ipcomp6_init_state+0xa8/0x800 net/ipv6/ipcomp6.c:153
 __xfrm_init_state+0x970/0x10c0 net/xfrm/xfrm_state.c:2493
 xfrm_state_construct net/xfrm/xfrm_user.c:626 [inline]
 xfrm_add_sa+0x1ee1/0x3ab3 net/xfrm/xfrm_user.c:683
 xfrm_user_rcv_msg+0x34c/0x6c0 net/xfrm/xfrm_user.c:2676
 netlink_rcv_skb+0x13c/0x380 net/netlink/af_netlink.c:2477
 xfrm_netlink_rcv+0x69/0x90 net/xfrm/xfrm_user.c:2684
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x43f/0x630 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x75d/0xc40 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0xb5/0xf0 net/socket.c:657
 ___sys_sendmsg+0x647/0x950 net/socket.c:2311
 __sys_sendmsg+0xd9/0x180 net/socket.c:2356
 __do_sys_sendmsg net/socket.c:2365 [inline]
 __se_sys_sendmsg net/socket.c:2363 [inline]
 __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2363
 do_syscall_64+0xca/0x5d0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4598e9
Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fdd39500c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004598e9
RDX: 0000000000000000 RSI: 0000000020000840 RDI: 0000000000000003
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdd395016d4
R13: 00000000004c7812 R14: 00000000004dd0b0 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..