Discussion:
BUG: unable to handle kernel paging request in ebt_among_mt_check (2)
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syzbot
2018-03-07 19:59:01 UTC
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Hello,

syzbot hit the following crash on net-next commit
0f3e9c97eb5a97972b0c0076a5cc01bb142f8e70 (Tue Mar 6 05:53:44 2018 +0000)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

So far this crash happened 61 times on net-next, upstream.
C reproducer is attached.
syzkaller reproducer is attached.
Raw console output is attached.
compiler: gcc (GCC) 7.1.1 20170620
.config is attached.

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Reported-by: syzbot+***@syzkaller.appspotmail.com
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audit: type=1400 audit(1520344231.282:6): avc: denied { map } for
pid=4159 comm="bash" path="/bin/bash" dev="sda1" ino=1457
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1
audit: type=1400 audit(1520344251.914:7): avc: denied { map } for
pid=4176 comm="syzkaller251034" path="/root/syzkaller251034479" 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
BUG: unable to handle kernel paging request at ffffc9003181552c
IP: poolsize_invalid net/bridge/netfilter/ebt_among.c:177 [inline]
IP: ebt_among_mt_check+0x137/0x390 net/bridge/netfilter/ebt_among.c:201
PGD 1dad2f067 P4D 1dad2f067 PUD 1dad30067 PMD 0
Oops: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 4176 Comm: syzkaller251034 Not tainted 4.16.0-rc4+ #254
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:poolsize_invalid net/bridge/netfilter/ebt_among.c:177 [inline]
RIP: 0010:ebt_among_mt_check+0x137/0x390
net/bridge/netfilter/ebt_among.c:201
RSP: 0018:ffff8801bc837210 EFLAGS: 00010246
RAX: 0000000000000007 RBX: ffffc90001815128 RCX: ffffffff851c0656
RDX: 0000000000000000 RSI: 0000000000000880 RDI: ffffc9003181552c
RBP: ffff8801bc837248 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff88614380 R11: 0000000000000000 R12: ffffc90001815928
R13: ffffc90031815128 R14: 0000000000000880 R15: 0000000000000414
FS: 00000000012ca880(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc9003181552c CR3: 00000001b0311004 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
xt_check_match+0x235/0x9c0 net/netfilter/x_tables.c:469
ebt_check_match net/bridge/netfilter/ebtables.c:374 [inline]
ebt_check_entry+0xbc3/0x1e00 net/bridge/netfilter/ebtables.c:704
translate_table+0xcf5/0x2290 net/bridge/netfilter/ebtables.c:945
do_replace_finish+0x79a/0x2620 net/bridge/netfilter/ebtables.c:1002
do_replace+0x333/0x4b0 net/bridge/netfilter/ebtables.c:1141
do_ebt_set_ctl+0xd4/0x110 net/bridge/netfilter/ebtables.c:1518
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
raw_setsockopt+0xb7/0xd0 net/ipv4/raw.c:870
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2979
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x441ab9
RSP: 002b:00007fff33f8e998 EFLAGS: 00000213 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000441ab9
RDX: 0000000000000080 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006cc018 R08: 0000000000000b40 R09: 00000000004002c8
R10: 0000000020000440 R11: 0000000000000213 R12: 00000000004033e0
R13: 0000000000403470 R14: 0000000000000000 R15: 0000000000000000
Code: 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48
89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 20 02 00 00 <41> 8b 85 04
04 00 00 3d a9 aa aa 0a 77 53 89 45 d0 e8 43 03 55
RIP: poolsize_invalid net/bridge/netfilter/ebt_among.c:177 [inline] RSP:
ffff8801bc837210
RIP: ebt_among_mt_check+0x137/0x390 net/bridge/netfilter/ebt_among.c:201
RSP: ffff8801bc837210
CR2: ffffc9003181552c
---[ end trace 94d069ff6a1006ce ]---


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