BUG: unable to handle kernel paging request in corrupted (2)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 49d05fe2 ipv6: rt6_check should return NULL if 'from' is N..
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=104b5f70600000
kernel config: https://syzkaller.appspot.com/x/.config?x=87305c3ca9c25c70
dashboard link: https://syzkaller.appspot.com/bug?extid=08b7a2c58acdfa12c82d
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=143a78f4600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+08b7a2...@syzkaller.appspotmail.com

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
BUG: unable to handle page fault for address: 00000000ffffffff
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 9ad32067 P4D 9ad32067 PUD 0
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 9920 Comm: syz-executor.1 Not tainted 5.2.0+ #91
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
BUG: kernel NULL pointer dereference, address: 0000000000000002
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 9ad32067 P4D 9ad32067 PUD 9ad33067 PMD 0
Oops: 0010 [#2] PREEMPT SMP KASAN
CPU: 0 PID: 9920 Comm: syz-executor.1 Not tainted 5.2.0+ #91
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:0x2
Code: Bad RIP value.
RSP: 0000:ffff888092932a20 EFLAGS: 00010086
RAX: 000000000000002d RBX: ffff888092932a40 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815c1016 RDI: ffffed1012526536
RBP: ffffffff81724d28 R08: 000000000000002d R09: ffffed1015d044fa
R10: ffffed1015d044f9 R11: ffff8880ae8227cf R12: ffffffff81b3e334
R13: 0000000000000010 R14: 0000000000000000 R15: 1ffff1101252654b
FS: 000055555572a940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd8 CR3: 000000009c4d1000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:


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[syzbot]

syzbot has bisected this bug to:

commit 9343ac87f2a4e09bf6e27b5f31e72e9e3a82abff
Author: Dave Stevenson <dave.st...@raspberrypi.org>
Date: Mon Jun 25 14:07:15 2018 +0000

net: lan78xx: Use s/w csum check on VLANs without tag stripping

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=102feb84600000
start commit: 49d05fe2 ipv6: rt6_check should return NULL if 'from' is N..
git tree: net
final crash: https://syzkaller.appspot.com/x/report.txt?x=122feb84600000
console output: https://syzkaller.appspot.com/x/log.txt?x=142feb84600000

kernel config: https://syzkaller.appspot.com/x/.config?x=87305c3ca9c25c70
dashboard link: https://syzkaller.appspot.com/bug?extid=08b7a2c58acdfa12c82d

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=143a78f4600000

Reported-by: syzbot+08b7a2...@syzkaller.appspotmail.com
Fixes: 9343ac87f2a4 ("net: lan78xx: Use s/w csum check on VLANs without tag
stripping")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[Dmitry Vyukov]

From the repro it looks like the same bpf stack overflow bug. +John
We need to dup them onto some canonical report for this bug, or this
becomes unmanageable.

#syz dup: kernel panic: corrupted stack end in dput