Discussion:
WARNING in compat_copy_entries (2)
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syzbot
2018-03-06 16:59:01 UTC
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Hello,

syzbot hit the following crash on upstream commit
ce380619fab99036f5e745c7a865b21c59f005f6 (Tue Mar 6 04:31:14 2018 +0000)
Merge tag 'please-pull-ia64_misc' of
git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux

So far this crash happened 11 times on upstream.
syzkaller reproducer is attached.
Raw console output is attached.
compiler: gcc (GCC) 7.1.1 20170620
.config is attached.
user-space arch: i386

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Reported-by: syzbot+***@syzkaller.appspotmail.com
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audit: type=1400 audit(1520347101.934:8): avc: denied { map } for
pid=4183 comm="syz-execprog" path="/root/syzkaller-shm886349459" dev="sda1"
ino=16482 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:object_r:file_t:s0 tclass=file permissive=1
IPVS: ftp: loaded support on port[0] = 21
WARNING: CPU: 1 PID: 4192 at net/bridge/netfilter/ebtables.c:2063
ebt_size_mwt net/bridge/netfilter/ebtables.c:2063 [inline]
WARNING: CPU: 1 PID: 4192 at net/bridge/netfilter/ebtables.c:2063
size_entry_mwt net/bridge/netfilter/ebtables.c:2140 [inline]
WARNING: CPU: 1 PID: 4192 at net/bridge/netfilter/ebtables.c:2063
compat_copy_entries+0xd92/0x1150 net/bridge/netfilter/ebtables.c:2179
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 4192 Comm: syz-executor0 Not tainted 4.16.0-rc4+ #253
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
panic+0x1e4/0x41c kernel/panic.c:183
__warn+0x1dc/0x200 kernel/panic.c:547
report_bug+0x211/0x2d0 lib/bug.c:184
fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178
fixup_bug arch/x86/kernel/traps.c:247 [inline]
do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296
do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986
RIP: 0010:ebt_size_mwt net/bridge/netfilter/ebtables.c:2063 [inline]
RIP: 0010:size_entry_mwt net/bridge/netfilter/ebtables.c:2140 [inline]
RIP: 0010:compat_copy_entries+0xd92/0x1150
net/bridge/netfilter/ebtables.c:2179
RSP: 0018:ffff8801bb5077e8 EFLAGS: 00010293
RAX: ffff8801bc82a580 RBX: 0000000000000000 RCX: ffffffff851ad5c2
RDX: 0000000000000000 RSI: ffffc90001853180 RDI: 0000000000000000
RBP: ffff8801bb507968 R08: 0000000000000004 R09: 0000000000000000
R10: ffffffff88613380 R11: 0000000000000001 R12: 0000000000000007
R13: dffffc0000000000 R14: ffff8801bb5079c8 R15: 000000000000000c
compat_do_replace+0x398/0x7d0 net/bridge/netfilter/ebtables.c:2268
compat_do_ebt_set_ctl+0x22a/0x2d0 net/bridge/netfilter/ebtables.c:2350
compat_nf_sockopt net/netfilter/nf_sockopt.c:144 [inline]
compat_nf_setsockopt+0x88/0x130 net/netfilter/nf_sockopt.c:156
compat_ip_setsockopt+0x8b/0xd0 net/ipv4/ip_sockglue.c:1285
inet_csk_compat_setsockopt+0x95/0x120 net/ipv4/inet_connection_sock.c:1041
compat_dccp_setsockopt+0x40/0x70 net/dccp/proto.c:589
compat_sock_common_setsockopt+0xb2/0x140 net/core/sock.c:2986
C_SYSC_setsockopt net/compat.c:403 [inline]
compat_SyS_setsockopt+0x17c/0x410 net/compat.c:386
do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline]
do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f35c99
RSP: 002b:00000000ff9c02cc EFLAGS: 00000282 ORIG_RAX: 000000000000016e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000080 RSI: 0000000020000240 RDI: 0000000000000240
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Dumping ftrace buffer:
(ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..


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