bisecting cause commit starting from 6ba1b005ffc388c2aeaddae20da29e4810dea298 building syzkaller on 19a8de55e59983d1ec21e544a4f35fb1ca4438a5 testing commit 6ba1b005ffc388c2aeaddae20da29e4810dea298 with gcc (GCC) 8.1.0 kernel signature: c6079d7503a4789b5c1b1e64789c04e46ee723a0344a5099fd1710230b9a8982 all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v5.7 testing commit 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 with gcc (GCC) 8.1.0 kernel signature: 01176ce5404aaaa9bcd0f38d508548c0335b9eabfecb7fbad9124d8341c47298 all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v5.6 testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.1.0 kernel signature: 688220d8e3daa01c64dc454e6b496061b0927c3ced9099810d2f736a384754af all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v5.5 testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.1.0 kernel signature: 15ab22fed7ced3964bf5b63e70028e149b5c1a72dadeafdd91703011aa160c88 all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v5.4 testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0 kernel signature: 77eaded37870de36a1c736701f8aa01439f7ff92a6cece468fb5deb24c2b0f63 all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v5.3 testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0 kernel signature: 44eee44be7b830976051d67221708a305565d2abdc8c9d9a5b1cfaca1f937061 all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0 kernel signature: 0c7bf643049dca3fa149bd8454b1d32d3697fc38fb6c1e06b352978460bdea9d all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v5.1 testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0 kernel signature: 4b8f78b567fa4a64e9ae656c9eb1a745377d058b35569a4d028c92ec03decba8 all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v5.0 testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0 kernel signature: 309ef66ecc423a08e59b95c4d51d2ad7dfa56e4cc748200f4d5d079b04af48aa all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v4.20 testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0 kernel signature: 87f16b9d1363aace129d5a4301dc13ba118e9a966870e9ba8ede3656c99a3725 all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v4.19 testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0 kernel signature: 600f13645b1cfbe855c9b9add28c505666f23e30660d0ab5cbc7aabb1ef87784 all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v4.18 testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.1.0 kernel signature: 2e9b55c476703f831ba39443469e2ea5a2d6ed83b2de4e3673417f4487b78a23 all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v4.17 testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.1.0 kernel signature: 7219f2991c51752233d5064779b0526f11cb85569cf7ebf40564879b48eb1e4d all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v4.16 testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0 kernel signature: 0e5f123c6c525e2fc17377b7a02e9264374e51cd24d2068d82b7ddf5909ff95a run #0: crashed: WARNING in ipvlan_unregister_nf_hook run #1: crashed: WARNING in ipvlan_unregister_nf_hook run #2: crashed: WARNING in ipvlan_unregister_nf_hook run #3: crashed: WARNING in ipvlan_unregister_nf_hook run #4: crashed: WARNING in ipvlan_unregister_nf_hook run #5: crashed: WARNING in ipvlan_unregister_nf_hook run #6: crashed: WARNING in batadv_is_on_batman_iface run #7: crashed: WARNING in ipvlan_unregister_nf_hook run #8: crashed: WARNING in ipvlan_unregister_nf_hook run #9: crashed: WARNING in ipvlan_unregister_nf_hook testing release v4.15 testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.1.0 kernel signature: 455d0e38f5e6971c1ed96c747787428ba17015bc3789201e3ef077baa1013072 all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v4.14 testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.1.0 kernel signature: 5e93dbdd0b89dce94e6ae0e752d1515bc539d9dd2603c0a62d22debd92c783db all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v4.13 testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.1.0 kernel signature: a6549fe8803805cd595b87f0039b836f2550cad209d9233937f195d8d51859a0 all runs: crashed: WARNING in ipvlan_unregister_nf_hook testing release v4.12 testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.1.0 kernel signature: db9034a25f7372af63fb95ecc4c57be73aee593c3f87f53b9b922c117dd1233f all runs: crashed: BUG: sleeping function called from invalid context in tap_get_minor testing release v4.11 testing commit a351e9b9fc24e982ec2f0e76379a49826036da12 with gcc (GCC) 7.3.0 kernel signature: d43dca9fd7b55abe5f4b5364e6f7e0e157632e0ca1fea31579ad75b859b2271b all runs: crashed: BUG: sleeping function called from invalid context in tap_get_minor testing release v4.10 testing commit c470abd4fde40ea6a0846a2beab642a578c0b8cd with gcc (GCC) 5.5.0 kernel signature: 844e02f03890fcf7b7898fb2ead3cfd52091f95ed8fe570e2badc706b130864b all runs: crashed: WARNING in batadv_is_on_batman_iface testing release v4.9 testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0 kernel signature: 1081bb19d38757f2edad2b320f7056b106ac6f2490dc567407db1b807d1bf030 run #0: crashed: WARNING in batadv_is_on_batman_iface run #1: crashed: WARNING in batadv_is_on_batman_iface run #2: crashed: WARNING in batadv_is_on_batman_iface run #3: crashed: WARNING in batadv_is_on_batman_iface run #4: crashed: WARNING in batadv_is_on_batman_iface run #5: crashed: WARNING in batadv_is_on_batman_iface run #6: crashed: WARNING in nf_unregister_net_hook run #7: crashed: WARNING in batadv_is_on_batman_iface run #8: crashed: WARNING in batadv_is_on_batman_iface run #9: crashed: WARNING in batadv_is_on_batman_iface testing release v4.8 testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0 kernel signature: 8bb7f1690c99a04d030a6584b42524a16a444685433783740d2fb6664f9043d0 all runs: crashed: WARNING in batadv_is_on_batman_iface testing release v4.7 testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0 kernel signature: 25d8b9f7dab453d22000aaa305e8570abd756ec2bfb375b066390b312541b3f6 run #0: crashed: WARNING in batadv_is_on_batman_iface run #1: crashed: KASAN: use-after-free Read in macsec_notify run #2: crashed: WARNING in batadv_is_on_batman_iface run #3: crashed: KASAN: use-after-free Read in macsec_notify run #4: crashed: WARNING in batadv_is_on_batman_iface run #5: crashed: WARNING in batadv_is_on_batman_iface run #6: crashed: WARNING in batadv_is_on_batman_iface run #7: crashed: KASAN: use-after-free Read in macsec_notify run #8: crashed: WARNING in batadv_is_on_batman_iface run #9: crashed: WARNING in batadv_is_on_batman_iface testing release v4.6 testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0 kernel signature: 07e6664db9fb53e92de3d8f07eefc864afa8f836f40a8a73c75541fa90d515e8 all runs: crashed: WARNING in sysfs_warn_dup revisions tested: 24, total time: 3h32m48.63128266s (build: 2h7m59.533932721s, test: 1h21m12.121198234s) the crash already happened on the oldest tested release commit msg: Linux 4.6 crash: WARNING in sysfs_warn_dup bond0: Enslaving bond_slave_1 as an active interface with an up link IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready ------------[ cut here ]------------ WARNING: CPU: 1 PID: 5870 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x7b/0xa0 fs/sysfs/dir.c:30 sysfs: cannot create duplicate filename '/class/macvtap/tap50' Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 5870 Comm: syz-executor.4 Not tainted 4.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 ffff8800b19defc8 ffffffff82c65e52 ffffffff85c81040 ffff8800b19df0a0 ffffffff85d2bb80 ffffffff8191bd7b 0000000000000009 ffff8800b19df090 ffffffff8160d884 0000000041b58ab3 ffffffff868f3a9a Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0x136/0x1d4 lib/dump_stack.c:51 [] panic+0x1af/0x348 kernel/panic.c:152 [] __warn+0x18d/0x1b0 kernel/panic.c:504 [] warn_slowpath_fmt+0x92/0xb0 kernel/panic.c:527 [] sysfs_warn_dup+0x7b/0xa0 fs/sysfs/dir.c:30 [] sysfs_do_create_link_sd.isra.0+0xd1/0xf0 fs/sysfs/symlink.c:51 [] sysfs_do_create_link fs/sysfs/symlink.c:80 [inline] [] sysfs_create_link+0x43/0xb0 fs/sysfs/symlink.c:92 [] device_add_class_symlinks drivers/base/core.c:891 [inline] [] device_add+0x677/0x1350 drivers/base/core.c:1086 [] device_create_groups_vargs+0x1c8/0x220 drivers/base/core.c:1709 [] device_create_vargs drivers/base/core.c:1749 [inline] [] device_create+0x88/0xa0 drivers/base/core.c:1785 [] macvtap_device_event+0x1c4/0x2a0 drivers/net/macvtap.c:1298 [] notifier_call_chain+0x8b/0x170 kernel/notifier.c:93 [] __raw_notifier_call_chain kernel/notifier.c:394 [inline] [] raw_notifier_call_chain+0x11/0x20 kernel/notifier.c:401 [] call_netdevice_notifiers_info+0x47/0x80 net/core/dev.c:1643 [] call_netdevice_notifiers net/core/dev.c:1659 [inline] [] register_netdevice+0x8e8/0xd00 net/core/dev.c:7027 [] macvlan_common_newlink+0x8b9/0x1090 drivers/net/macvlan.c:1316 [] macvtap_newlink+0xbf/0x110 drivers/net/macvtap.c:471 [] rtnl_newlink+0xd4b/0x1230 net/core/rtnetlink.c:2466 [] rtnetlink_rcv_msg+0x222/0x680 net/core/rtnetlink.c:3513 [] netlink_rcv_skb+0x242/0x350 net/netlink/af_netlink.c:2277 [] rtnetlink_rcv+0x25/0x30 net/core/rtnetlink.c:3519 [] netlink_unicast_kernel net/netlink/af_netlink.c:1214 [inline] [] netlink_unicast+0x3da/0x560 net/netlink/af_netlink.c:1240 [] netlink_sendmsg+0x9bb/0xb40 net/netlink/af_netlink.c:1786 [] sock_sendmsg_nosec net/socket.c:612 [inline] [] sock_sendmsg+0xb5/0xf0 net/socket.c:622 [] SYSC_sendto net/socket.c:1648 [inline] [] SyS_sendto+0x1ca/0x290 net/socket.c:1616 [] entry_SYSCALL_64_fastpath+0x23/0xc1 Kernel Offset: disabled