bisecting cause commit starting from ac935d22736659be734251247dcc6f444fb98972 building syzkaller on 35b8eb3041516c17ae2eb3b09a33b7429ade33d3 testing commit ac935d22736659be734251247dcc6f444fb98972 with gcc (GCC) 8.1.0 kernel signature: b6de51524b6c3366fe774a02cff58a9f46b93937fc4a087411fcf575d3b44243 all runs: crashed: WARNING: proc registration bug in snmp6_register_dev testing release v5.6 testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.1.0 kernel signature: 20e4812ebfa5cf0f0f55e65548cb602a5b584069fcfee2a9a6a508d0409705ce all runs: OK # git bisect start ac935d22736659be734251247dcc6f444fb98972 7111951b8d4973bda27ff663f2cf18b663d15b48 Bisecting: 7631 revisions left to test after this (roughly 13 steps) [50a5de895dbe5df947b3a695777db5b2c313e065] Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma testing commit 50a5de895dbe5df947b3a695777db5b2c313e065 with gcc (GCC) 8.1.0 kernel signature: 741d5ec51dd9a7ea38a36e41867653c9b6b917acf4a0c0e704cafb0ba1ee85f4 all runs: crashed: WARNING: proc registration bug in snmp6_register_dev # git bisect bad 50a5de895dbe5df947b3a695777db5b2c313e065 Bisecting: 4204 revisions left to test after this (roughly 12 steps) [56a451b780676bc1cdac011735fe2869fa2e9abf] Merge tag 'ntb-5.7' of git://github.com/jonmason/ntb testing commit 56a451b780676bc1cdac011735fe2869fa2e9abf with gcc (GCC) 8.1.0 kernel signature: db6930a4ba732f31379a7b9e7ffa55a7cba98b927283ef3b271236f18742dfaa all runs: OK # git bisect good 56a451b780676bc1cdac011735fe2869fa2e9abf Bisecting: 2102 revisions left to test after this (roughly 11 steps) [6c5bc8fe4e1915da8296a665bd742dbe34de02f0] ethtool: add EEE_NTF notification testing commit 6c5bc8fe4e1915da8296a665bd742dbe34de02f0 with gcc (GCC) 8.1.0 kernel signature: 46afd149da3b4fc84ddd35ac081a893509373a3d6ccabcee752879cce2edea02 all runs: crashed: WARNING: proc registration bug in snmp6_register_dev # git bisect bad 6c5bc8fe4e1915da8296a665bd742dbe34de02f0 Bisecting: 1050 revisions left to test after this (roughly 10 steps) [1fcbebf115d9ce077c2ba5ecfb521cc1eedcb467] ionic: drop ethtool driver version testing commit 1fcbebf115d9ce077c2ba5ecfb521cc1eedcb467 with gcc (GCC) 8.1.0 kernel signature: 7e0e89569460455a3524f31fc3988f57c4b5627cd970d021d254dc33d76d6f41 all runs: crashed: WARNING: proc registration bug in snmp6_register_dev # git bisect bad 1fcbebf115d9ce077c2ba5ecfb521cc1eedcb467 Bisecting: 525 revisions left to test after this (roughly 9 steps) [9534784209e8697d8c3b65baa286aceba1278382] net: axienet: use resolved link config in mac_link_up() testing commit 9534784209e8697d8c3b65baa286aceba1278382 with gcc (GCC) 8.1.0 kernel signature: 5c3257d44019b73a28a516cbb1b27319abf0d91973a5af5372d0646fa5713ce4 all runs: OK # git bisect good 9534784209e8697d8c3b65baa286aceba1278382 Bisecting: 278 revisions left to test after this (roughly 8 steps) [442a46ad103ed38ddaaba1d9f7d316beb492c66e] bcm63xx_enet: remove redundant variable definitions testing commit 442a46ad103ed38ddaaba1d9f7d316beb492c66e with gcc (GCC) 8.1.0 kernel signature: 37df639078bf5f7ac33fbe2c02dade95dba4d915a8641e806a4971037a928218 all runs: crashed: WARNING: proc registration bug in snmp6_register_dev # git bisect bad 442a46ad103ed38ddaaba1d9f7d316beb492c66e Bisecting: 123 revisions left to test after this (roughly 7 steps) [bb4cf02d4c74f0db60f58c406ddfdfed16d14f84] netdevice: Replace zero-length array with flexible-array member testing commit bb4cf02d4c74f0db60f58c406ddfdfed16d14f84 with gcc (GCC) 8.1.0 kernel signature: 245fe46a3744492ed2283ba325ee1487eb2443847c55abba5525b12c5ccf34a9 all runs: crashed: WARNING: proc registration bug in snmp6_register_dev # git bisect bad bb4cf02d4c74f0db60f58c406ddfdfed16d14f84 Bisecting: 78 revisions left to test after this (roughly 6 steps) [812285fa5ab129e3a55682314bf235f701564310] Merge branch 'bpf_sk_storage_via_inet_diag' testing commit 812285fa5ab129e3a55682314bf235f701564310 with gcc (GCC) 8.1.0 kernel signature: 8935588b9d50c0491aea578a6cc43e6fbe191db4584aac6c032e5fc64d7e8ae9 all runs: OK # git bisect good 812285fa5ab129e3a55682314bf235f701564310 Bisecting: 39 revisions left to test after this (roughly 5 steps) [b90feaff2a2cbf339069adec4bfd6091cfb44b50] net: sched: Replace zero-length array with flexible-array member testing commit b90feaff2a2cbf339069adec4bfd6091cfb44b50 with gcc (GCC) 8.1.0 kernel signature: ad5e08a8615fed01731d72a42fc1a9dab1023ff6da6a671302e0ffa89a55ad29 all runs: OK # git bisect good b90feaff2a2cbf339069adec4bfd6091cfb44b50 Bisecting: 19 revisions left to test after this (roughly 4 steps) [e8316026d538873f60f41dab4caaa493a21684b0] net: lwtunnel: Replace zero-length array with flexible-array member testing commit e8316026d538873f60f41dab4caaa493a21684b0 with gcc (GCC) 8.1.0 kernel signature: a5c1f5f921eb218f810aeb8f0bba30913f9cd08faca4b4544d43b3f092875683 all runs: crashed: WARNING: proc registration bug in snmp6_register_dev # git bisect bad e8316026d538873f60f41dab4caaa493a21684b0 Bisecting: 9 revisions left to test after this (roughly 3 steps) [81390d0c4e56ac7752c97d7e8209357673d1a8ab] hsr: remove unnecessary rcu_read_lock() in hsr module testing commit 81390d0c4e56ac7752c97d7e8209357673d1a8ab with gcc (GCC) 8.1.0 kernel signature: e4af21500c59f792aa18e9e1f76c4f88120748403b569b41ab510e035741b37c all runs: OK # git bisect good 81390d0c4e56ac7752c97d7e8209357673d1a8ab Bisecting: 4 revisions left to test after this (roughly 2 steps) [de30181093891d1735a700e7c628d0135f53ed35] Merge branch 'net-ethtool-Introduce-link_ksettings-API-for-virtual-network-devices' testing commit de30181093891d1735a700e7c628d0135f53ed35 with gcc (GCC) 8.1.0 kernel signature: e2af07ca3f81384ef316df7ca47bb24f249e15a328f615895500952dabeee7cb all runs: crashed: WARNING: proc registration bug in snmp6_register_dev # git bisect bad de30181093891d1735a700e7c628d0135f53ed35 Bisecting: 2 revisions left to test after this (roughly 1 step) [68e2c37690b0da7539cfa2928bf1e4f50d88a1bb] Merge branch 'hsr-several-code-cleanup-for-hsr-module' testing commit 68e2c37690b0da7539cfa2928bf1e4f50d88a1bb with gcc (GCC) 8.1.0 kernel signature: dce9e3e7ef170d2dc74ade0b1200c55407e2585e9084f411dd4d2edb41475834 all runs: crashed: WARNING: proc registration bug in snmp6_register_dev # git bisect bad 68e2c37690b0da7539cfa2928bf1e4f50d88a1bb Bisecting: 0 revisions left to test after this (roughly 0 steps) [e0a4b99773d3d8d3fb40087805f8fd858a23e582] hsr: use upper/lower device infrastructure testing commit e0a4b99773d3d8d3fb40087805f8fd858a23e582 with gcc (GCC) 8.1.0 kernel signature: d1da7715549032b8960f0f9e1c5241daf87ee8f27d501e4190462fb39e4ed7f0 all runs: crashed: WARNING: proc registration bug in snmp6_register_dev # git bisect bad e0a4b99773d3d8d3fb40087805f8fd858a23e582 e0a4b99773d3d8d3fb40087805f8fd858a23e582 is the first bad commit commit e0a4b99773d3d8d3fb40087805f8fd858a23e582 Author: Taehee Yoo Date: Fri Feb 28 18:02:10 2020 +0000 hsr: use upper/lower device infrastructure netdev_upper_dev_link() is useful to manage lower/upper interfaces. And this function internally validates looping, maximum depth. All or most virtual interfaces that could have a real interface (e.g. macsec, macvlan, ipvlan etc.) use lower/upper infrastructure. Signed-off-by: Taehee Yoo Signed-off-by: David S. Miller net/hsr/hsr_device.c | 32 ++++++++++++++++++++------------ net/hsr/hsr_main.c | 3 ++- net/hsr/hsr_slave.c | 35 ++++++++++++++++++----------------- 3 files changed, 40 insertions(+), 30 deletions(-) culprit signature: d1da7715549032b8960f0f9e1c5241daf87ee8f27d501e4190462fb39e4ed7f0 parent signature: e4af21500c59f792aa18e9e1f76c4f88120748403b569b41ab510e035741b37c revisions tested: 16, total time: 3h21m51.913104628s (build: 1h43m50.037179455s, test: 1h36m45.999329922s) first bad commit: e0a4b99773d3d8d3fb40087805f8fd858a23e582 hsr: use upper/lower device infrastructure cc: ["ap420073@gmail.com" "davem@davemloft.net" "edumazet@google.com" "kuba@kernel.org" "linux-kernel@vger.kernel.org" "netdev@vger.kernel.org" "xiyou.wangcong@gmail.com"] crash: WARNING: proc registration bug in snmp6_register_dev ------------[ cut here ]------------ proc_dir_entry 'dev_snmp6/hsr1' already registered WARNING: CPU: 0 PID: 8621 at fs/proc/generic.c:363 proc_register+0x2e6/0x480 fs/proc/generic.c:362 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 8621 Comm: syz-executor.2 Not tainted 5.6.0-rc3-syzkaller #0 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+0x128/0x182 lib/dump_stack.c:118 panic+0x22a/0x4e3 kernel/panic.c:221 __warn.cold.10+0x25/0x26 kernel/panic.c:582 report_bug+0x1ad/0x270 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:174 [inline] do_error_trap+0x123/0x210 arch/x86/kernel/traps.c:267 do_invalid_op+0x31/0x40 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027 RIP: 0010:proc_register+0x2e6/0x480 fs/proc/generic.c:362 Code: 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 01 00 0f 85 8c 01 00 00 48 8b b5 d0 00 00 00 48 c7 c7 e0 bb 77 87 e8 b6 06 78 ff <0f> 0b 48 c7 c7 60 48 ca 88 e8 5c ae 58 05 4c 89 ea 48 b8 00 00 00 RSP: 0018:ffffc90004326d40 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff8880a784e700 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000008 RDI: ffffffff8b6864a0 RBP: ffff88809eb99e00 R08: ffffed1015d06661 R09: ffffed1015d06661 R10: ffffed1015d06660 R11: ffff8880ae833307 R12: ffffed1014f09cfb R13: ffff8880a784e78c R14: ffff8880a784e7d0 R15: ffff88808cdfc700 proc_create_single_data+0xba/0x110 fs/proc/generic.c:622 snmp6_register_dev+0xa7/0x130 net/ipv6/proc.c:254 ipv6_add_dev+0x4b3/0xed0 net/ipv6/addrconf.c:406 addrconf_notify+0x4d1/0x1ea0 net/ipv6/addrconf.c:3491 notifier_call_chain+0x86/0x150 kernel/notifier.c:83 call_netdevice_notifiers_extack net/core/dev.c:1960 [inline] call_netdevice_notifiers net/core/dev.c:1974 [inline] register_netdevice+0x60b/0xec0 net/core/dev.c:9400 hsr_dev_finalize+0x4e0/0x6d2 net/hsr/hsr_device.c:486 hsr_newlink+0x221/0x430 net/hsr/hsr_netlink.c:77 __rtnl_newlink+0xbe9/0x1250 net/core/rtnetlink.c:3319 rtnl_newlink+0x5c/0x80 net/core/rtnetlink.c:3377 rtnetlink_rcv_msg+0x346/0x8c0 net/core/rtnetlink.c:5440 netlink_rcv_skb+0x119/0x340 net/netlink/af_netlink.c:2478 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x434/0x630 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x714/0xc60 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xac/0xe0 net/socket.c:672 ____sys_sendmsg+0x54e/0x750 net/socket.c:2343 ___sys_sendmsg+0xe4/0x160 net/socket.c:2397 __sys_sendmsg+0xce/0x170 net/socket.c:2430 do_syscall_64+0xc6/0x5e0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f33b6a99c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000500ce0 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000003 RBP: 000000000078c0e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000a04 R14: 00000000004ccbcc R15: 00007f33b6a9a6d4 Kernel Offset: disabled Rebooting in 86400 seconds..