Hello, syzbot found the following crash on: HEAD commit: c6a6aed994b6 kmsan: remove dead code to trigger syzbot build git tree: https://github.com/google/kmsan.git/master console output: https://syzkaller.appspot.com/x/log.txt?x=17bde74f800000 kernel config: https://syzkaller.appspot.com/x/.config?x=848e40757852af3e dashboard link: https://syzkaller.appspot.com/bug?extid=da4494182233c23a5fcf compiler: clang version 7.0.0 (trunk 334104) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+da4494182233c23a5fcf at syzkaller.appspotmail.com =================================================================BUG: KMSAN: uninit-value in ebt_stp_mt_check+0x24b/0x450 net/bridge/netfilter/ebt_stp.c:162 CPU: 0 PID: 12006 Comm: syz-executor7 Not tainted 4.17.0+ #3 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+0x185/0x1d0 lib/dump_stack.c:113 kmsan_report+0x149/0x260 mm/kmsan/kmsan.c:1084 __msan_warning_32+0x6e/0xc0 mm/kmsan/kmsan_instr.c:620 ebt_stp_mt_check+0x24b/0x450 net/bridge/netfilter/ebt_stp.c:162 xt_check_match+0x1438/0x1650 net/netfilter/x_tables.c:506 ebt_check_match net/bridge/netfilter/ebtables.c:372 [inline] ebt_check_entry net/bridge/netfilter/ebtables.c:702 [inline] translate_table+0x4e88/0x6120 net/bridge/netfilter/ebtables.c:943 do_replace_finish+0x1258/0x2ea0 net/bridge/netfilter/ebtables.c:999 do_replace+0x719/0x780 net/bridge/netfilter/ebtables.c:1138 do_ebt_set_ctl+0x2ab/0x3c0 net/bridge/netfilter/ebtables.c:1517 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x47c/0x4e0 net/netfilter/nf_sockopt.c:115 ip_setsockopt+0x24b/0x2b0 net/ipv4/ip_sockglue.c:1251 udp_setsockopt+0x108/0x1b0 net/ipv4/udp.c:2416 sock_common_setsockopt+0x13b/0x170 net/core/sock.c:3039 __sys_setsockopt+0x496/0x540 net/socket.c:1903 __do_sys_setsockopt net/socket.c:1914 [inline] __se_sys_setsockopt net/socket.c:1911 [inline] __x64_sys_setsockopt+0x15c/0x1c0 net/socket.c:1911 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x4559f9 RSP: 002b:00007f45b9246c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f45b92476d4 RCX: 00000000004559f9 RDX: 0000000000000080 RSI: 0000000000000000 RDI: 0000000000000014 RBP: 000000000072bea0 R08: 0000000000000300 R09: 0000000000000000 R10: 0000000020000480 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004c0d6d R14: 00000000004d07c8 R15: 0000000000000000 Local variable description: ----mtpar.i at translate_table Variable was created at: translate_table+0xbb/0x6120 net/bridge/netfilter/ebtables.c:831 do_replace_finish+0x1258/0x2ea0 net/bridge/netfilter/ebtables.c:999 ================================================================= --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller at googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with syzbot.
On Thu, Jun 7, 2018 at 7:29 PM, syzbot <syzbot+da4494182233c23a5fcf at syzkaller.appspotmail.com> wrote:> Hello, > > syzbot found the following crash on: > > HEAD commit: c6a6aed994b6 kmsan: remove dead code to trigger syzbot build > git tree: https://github.com/google/kmsan.git/master > console output: https://syzkaller.appspot.com/x/log.txt?x=17bde74f800000 > kernel config: https://syzkaller.appspot.com/x/.config?x=848e40757852af3e > dashboard link: https://syzkaller.appspot.com/bug?extid=da4494182233c23a5fcf > compiler: clang version 7.0.0 (trunk 334104) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+da4494182233c23a5fcf at syzkaller.appspotmail.comHi Stephen, This strikes again. The first part of the check is par->nft_compat. I don't see where ebt_check_entry initializes it. Should it? Or matches should not look at it?> =================================================================> BUG: KMSAN: uninit-value in ebt_stp_mt_check+0x24b/0x450 > net/bridge/netfilter/ebt_stp.c:162 > CPU: 0 PID: 12006 Comm: syz-executor7 Not tainted 4.17.0+ #3 > 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+0x185/0x1d0 lib/dump_stack.c:113 > kmsan_report+0x149/0x260 mm/kmsan/kmsan.c:1084 > __msan_warning_32+0x6e/0xc0 mm/kmsan/kmsan_instr.c:620 > ebt_stp_mt_check+0x24b/0x450 net/bridge/netfilter/ebt_stp.c:162 > xt_check_match+0x1438/0x1650 net/netfilter/x_tables.c:506 > ebt_check_match net/bridge/netfilter/ebtables.c:372 [inline] > ebt_check_entry net/bridge/netfilter/ebtables.c:702 [inline] > translate_table+0x4e88/0x6120 net/bridge/netfilter/ebtables.c:943 > do_replace_finish+0x1258/0x2ea0 net/bridge/netfilter/ebtables.c:999 > do_replace+0x719/0x780 net/bridge/netfilter/ebtables.c:1138 > do_ebt_set_ctl+0x2ab/0x3c0 net/bridge/netfilter/ebtables.c:1517 > nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] > nf_setsockopt+0x47c/0x4e0 net/netfilter/nf_sockopt.c:115 > ip_setsockopt+0x24b/0x2b0 net/ipv4/ip_sockglue.c:1251 > udp_setsockopt+0x108/0x1b0 net/ipv4/udp.c:2416 > sock_common_setsockopt+0x13b/0x170 net/core/sock.c:3039 > __sys_setsockopt+0x496/0x540 net/socket.c:1903 > __do_sys_setsockopt net/socket.c:1914 [inline] > __se_sys_setsockopt net/socket.c:1911 [inline] > __x64_sys_setsockopt+0x15c/0x1c0 net/socket.c:1911 > do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x4559f9 > RSP: 002b:00007f45b9246c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 > RAX: ffffffffffffffda RBX: 00007f45b92476d4 RCX: 00000000004559f9 > RDX: 0000000000000080 RSI: 0000000000000000 RDI: 0000000000000014 > RBP: 000000000072bea0 R08: 0000000000000300 R09: 0000000000000000 > R10: 0000000020000480 R11: 0000000000000246 R12: 00000000ffffffff > R13: 00000000004c0d6d R14: 00000000004d07c8 R15: 0000000000000000 > > Local variable description: ----mtpar.i at translate_table > Variable was created at: > translate_table+0xbb/0x6120 net/bridge/netfilter/ebtables.c:831 > do_replace_finish+0x1258/0x2ea0 net/bridge/netfilter/ebtables.c:999 > =================================================================> > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller at googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > syzbot. > > -- > You received this message because you are subscribed to the Google Groups > "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to syzkaller-bugs+unsubscribe at googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/syzkaller-bugs/0000000000009a3b5b056e109e42%40google.com. > For more options, visit https://groups.google.com/d/optout.
syzbot has found a reproducer for the following crash on: HEAD commit: c6a6aed994b6 kmsan: remove dead code to trigger syzbot build git tree: https://github.com/google/kmsan.git/master console output: https://syzkaller.appspot.com/x/log.txt?x=122606bf800000 kernel config: https://syzkaller.appspot.com/x/.config?x=848e40757852af3e dashboard link: https://syzkaller.appspot.com/bug?extid=da4494182233c23a5fcf compiler: clang version 7.0.0 (trunk 334104) syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=121f481f800000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=121fbbd7800000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+da4494182233c23a5fcf at syzkaller.appspotmail.com random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) =================================================================BUG: KMSAN: uninit-value in ebt_stp_mt_check+0x24b/0x450 net/bridge/netfilter/ebt_stp.c:162 CPU: 1 PID: 4523 Comm: syz-executor710 Not tainted 4.17.0+ #3 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+0x185/0x1d0 lib/dump_stack.c:113 kmsan_report+0x149/0x260 mm/kmsan/kmsan.c:1084 __msan_warning_32+0x6e/0xc0 mm/kmsan/kmsan_instr.c:620 ebt_stp_mt_check+0x24b/0x450 net/bridge/netfilter/ebt_stp.c:162 xt_check_match+0x1438/0x1650 net/netfilter/x_tables.c:506 ebt_check_match net/bridge/netfilter/ebtables.c:372 [inline] ebt_check_entry net/bridge/netfilter/ebtables.c:702 [inline] translate_table+0x4e88/0x6120 net/bridge/netfilter/ebtables.c:943 do_replace_finish+0x1258/0x2ea0 net/bridge/netfilter/ebtables.c:999 do_replace+0x719/0x780 net/bridge/netfilter/ebtables.c:1138 do_ebt_set_ctl+0x2ab/0x3c0 net/bridge/netfilter/ebtables.c:1517 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x47c/0x4e0 net/netfilter/nf_sockopt.c:115 ip_setsockopt+0x24b/0x2b0 net/ipv4/ip_sockglue.c:1251 udp_setsockopt+0x108/0x1b0 net/ipv4/udp.c:2416 sock_common_setsockopt+0x13b/0x170 net/core/sock.c:3039 __sys_setsockopt+0x496/0x540 net/socket.c:1903 __do_sys_setsockopt net/socket.c:1914 [inline] __se_sys_setsockopt net/socket.c:1911 [inline] __x64_sys_setsockopt+0x15c/0x1c0 net/socket.c:1911 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x43fd89 RSP: 002b:00007ffc9d7edb28 EFLAGS: 00000213 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fd89 RDX: 0000000000000080 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00000000006ca018 R08: 0000000000000300 R09: 00000000004002c8 R10: 0000000020000480 R11: 0000000000000213 R12: 00000000004016b0 R13: 0000000000401740 R14: 0000000000000000 R15: 0000000000000000 Local variable description: ----mtpar.i at translate_table Variable was created at: translate_table+0xbb/0x6120 net/bridge/netfilter/ebtables.c:831 do_replace_finish+0x1258/0x2ea0 net/bridge/netfilter/ebtables.c:999 ==================================================================