On Tue, Jan 30, 2018 at 5:16 PM, Eric Biggers [off-list ref] wrote:

On Wed, Jan 03, 2018 at 10:53:02AM -0800, 'Wei Wang' via syzkaller-bugs wrote:

quoted

On Wed, Jan 3, 2018 at 8:16 AM, David Ahern [off-list ref] wrote:

quoted

[ +weiwan@google.com ]

On 1/2/18 3:58 PM, syzbot wrote:

quoted

Hello,

syzkaller hit the following crash on
61233580f1f33c50e159c50e24d80ffd2ba2e06b
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.
C reproducer is attached
syzkaller reproducer is attached. See https://goo.gl/kgGztJ
for information about syzkaller reproducers


IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+0693adff3f83403dc5da@syzkaller.appspotmail.com
It will help syzbot understand when the bug is fixed. See footer for
details.
If you forward the report, please keep this part and the footer.

This crash seemed to stop occurring around Jan 8.  Wei, next time can you please
use the suggested Reported-by line so that syzbot knows which commit is meant to
fix the bug?  I assume it was this one:

Noted. Will do.

#syz fix: ipv6: fix general protection fault in fib6_add()

Yes. Correct.

Thanks!

- Eric

quoted

quoted

quoted

audit: type=1400 audit(1514594846.496:7): avc:  denied  { map } for
pid=3201 comm="syzkaller001778" path="/root/syzkaller001778299"
dev="sda1" ino=16481
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
IPv6: Can't replace route, no match found
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 3201 Comm: syzkaller001778 Not tainted 4.15.0-rc5+ #151
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:fib6_add+0x736/0x15a0 net/ipv6/ip6_fib.c:1244

pn could be NULL if fib6_add_1() failed. Will submit a fix for this.

quoted

quoted

RSP: 0018:ffff8801c7626a70 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000020 RCX: ffffffff84794465
RDX: 0000000000000004 RSI: ffff8801d38935f0 RDI: 0000000000000282
RBP: ffff8801c7626da0 R08: 1ffff10038ec4c35 R09: 0000000000000000
R10: ffff8801c7626c68 R11: 0000000000000000 R12: 00000000fffffffe
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000009
FS:  0000000000000000(0000) GS:ffff8801db200000(0063)
knlGS:0000000009b70840
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000020be1000 CR3: 00000001d585a006 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __ip6_ins_rt+0x6c/0x90 net/ipv6/route.c:1006
 ip6_route_multipath_add+0xd14/0x16c0 net/ipv6/route.c:3833
 inet6_rtm_newroute+0xdc/0x160 net/ipv6/route.c:3957
 rtnetlink_rcv_msg+0x733/0x1020 net/core/rtnetlink.c:4411
 netlink_rcv_skb+0x21e/0x460 net/netlink/af_netlink.c:2408
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4423
 netlink_unicast_kernel net/netlink/af_netlink.c:1275 [inline]
 netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1301
 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1864
 sock_sendmsg_nosec net/socket.c:636 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:646
 sock_write_iter+0x31a/0x5d0 net/socket.c:915
 call_write_iter include/linux/fs.h:1772 [inline]
 do_iter_readv_writev+0x525/0x7f0 fs/read_write.c:653
 do_iter_write+0x154/0x540 fs/read_write.c:932
 compat_writev+0x225/0x420 fs/read_write.c:1246
 do_compat_writev+0x115/0x220 fs/read_write.c:1267
 C_SYSC_writev fs/read_write.c:1278 [inline]
 compat_SyS_writev+0x26/0x30 fs/read_write.c:1274
 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline]
 do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389
 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:125
RIP: 0023:0xf7f1fc79
RSP: 002b:00000000ffb61bfc EFLAGS: 00000203 ORIG_RAX: 0000000000000092
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000204aaff0
RDX: 0000000000000001 RSI: 0000000000000167 RDI: 0000000000000010
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Code: f1 a9 f6 fc e8 2c f2 e2 fc 85 c0 0f 85 d5 03 00 00 49 8d 5e 20 e8
db a9 f6 fc 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c
02 00 0f 85 5a 0c 00 00 4d 39 ee 4d 8b 7e 20 0f 95 c0 4c
RIP: fib6_add+0x736/0x15a0 net/ipv6/ip6_fib.c:1244 RSP: ffff8801c7626a70
---[ end trace 956c65133fcfff88 ]---


---
This bug is generated by a dumb bot. It may contain errors.
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