bisecting cause commit starting from e595dd94515ed6bc5ba38fce0f9598db8c0ee9a9 building syzkaller on 05736b290dd5af17adbb0fb5ea67405a0167a7c8 testing commit e595dd94515ed6bc5ba38fce0f9598db8c0ee9a9 with gcc (GCC) 8.1.0 kernel signature: 4e401bdc89011e2fa76774879bca140d2242dcaef51313fb1122036b07828dbc all runs: crashed: WARNING in inc_nlink testing release v5.5 testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.1.0 kernel signature: 54fdd3b2af8c87b50d4c4ad8695600540c811af503930172ead18648f4b87df4 all runs: crashed: WARNING in inc_nlink testing release v5.4 testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0 kernel signature: d1a746c9a665ac7dd2e9476778722ecdac8d11f729676ee5c18a4ac989aba166 all runs: crashed: WARNING in inc_nlink testing release v5.3 testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0 kernel signature: cf54251e3fafd382e190b57de504238fc9eeb67311628c5accb1ff99514b76a8 all runs: crashed: WARNING in inc_nlink testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0 kernel signature: c723206c1daee7b544fcff702f978ec0e91502b73d57147e7830141a73199773 all runs: crashed: WARNING in inc_nlink testing release v5.1 testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0 kernel signature: 6dca22413f0032733a9346fad95bfc55efbeda9bc5e6c740b2e294d59354cb20 all runs: crashed: WARNING in inc_nlink testing release v5.0 testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0 kernel signature: 79d44e84db8ec961c275dda5a2e7169ca2c0a5b3a06cd1010e5918b78fd66ad8 all runs: crashed: WARNING in inc_nlink testing release v4.20 testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0 kernel signature: e18e057ebbe9c614ebfec1f14f8f010c4da6cfc5f33c19ef3999dea88e776d73 run #0: crashed: WARNING in inc_nlink run #1: crashed: WARNING in inc_nlink run #2: crashed: WARNING in corrupted run #3: crashed: WARNING in inc_nlink run #4: crashed: WARNING in inc_nlink run #5: crashed: WARNING in inc_nlink run #6: crashed: WARNING in inc_nlink run #7: crashed: WARNING in inc_nlink run #8: crashed: WARNING in inc_nlink run #9: crashed: WARNING in corrupted testing release v4.19 testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0 kernel signature: 45bf234b05ab5afeea127d2f333283efae8d863b375935e6d103b3b876174415 run #0: crashed: WARNING in inc_nlink run #1: crashed: WARNING in inc_nlink run #2: crashed: WARNING in corrupted run #3: crashed: WARNING in inc_nlink run #4: crashed: WARNING in inc_nlink run #5: crashed: WARNING in inc_nlink run #6: crashed: WARNING in inc_nlink run #7: crashed: WARNING in inc_nlink run #8: crashed: WARNING in inc_nlink run #9: crashed: WARNING in inc_nlink testing release v4.18 testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.1.0 kernel signature: 9163764ba6faf0291f1072355c932b390a36bc5a082596b2c974a12ae0d9c89b run #0: crashed: WARNING in inc_nlink run #1: crashed: WARNING in corrupted run #2: crashed: WARNING in inc_nlink run #3: crashed: WARNING in corrupted run #4: crashed: WARNING in inc_nlink run #5: crashed: WARNING in inc_nlink run #6: crashed: WARNING in corrupted run #7: crashed: WARNING in inc_nlink run #8: crashed: WARNING in inc_nlink run #9: crashed: WARNING in inc_nlink testing release v4.17 testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.1.0 kernel signature: 570dabb246726a1b1b503bbf3034867187fefdb94e5a3e97d2507303c6a9d23f run #0: crashed: WARNING in inc_nlink run #1: crashed: WARNING in inc_nlink run #2: crashed: WARNING in inc_nlink run #3: crashed: WARNING in inc_nlink run #4: crashed: WARNING in corrupted run #5: crashed: WARNING in inc_nlink run #6: crashed: WARNING in inc_nlink run #7: crashed: WARNING in inc_nlink run #8: crashed: WARNING in inc_nlink run #9: crashed: WARNING in inc_nlink testing release v4.16 testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0 kernel signature: d69f11a86250f2cb23aa8e777b2a6e601b1349078fc80937883ace8c2cf74804 all runs: crashed: WARNING in inc_nlink testing release v4.15 testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.1.0 kernel signature: 2c35cb398c090b7445c842eec17cf4c794044d48c913081bb5ca5183bfa03391 all runs: crashed: WARNING in inc_nlink testing release v4.14 testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.1.0 kernel signature: 78bb364a0bba7e46c801a154ef6985687032eb7937747d4f765e85fcd6018aa4 all runs: crashed: WARNING in inc_nlink testing release v4.13 testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.1.0 kernel signature: ca8ec077699094b82d6d76dabfdfa05e25743bed4cd59e66d1517ae49507f8c4 all runs: crashed: WARNING in inc_nlink testing release v4.12 testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.1.0 kernel signature: 03adfbedc0dddee03faeab4c2894f6807cbc165e2d535007f02ece9685cd7b75 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: 7e9c474414f98c898f312bfad9784ca7a86a7eec4987db47be9f84307768701a 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: c7f7eaad9dbb1e8f961502c74f7ae44c22f7a85fbbf42d81787fde13aabfd223 all runs: crashed: WARNING in inc_nlink testing release v4.9 testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0 kernel signature: 99f50923a9d86ace31057bc2ba83de39060a2a9c012133677b0d877721331265 all runs: crashed: WARNING in inc_nlink testing release v4.8 testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0 kernel signature: 75c99982bff6dcc317854957d563f564d0567b798c1b0d952faa74cf0863a444 all runs: crashed: WARNING in inc_nlink testing release v4.7 testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0 kernel signature: 8e2bf359f810c825bf0022e0000b4e44d9c745f7e7312b042e620efdd49738a4 all runs: crashed: WARNING in inc_nlink testing release v4.6 testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0 kernel signature: d709e987f8e2dddd79677297580f46af94338dac454e41152c20655e91de9b3b all runs: crashed: WARNING in sysfs_warn_dup revisions tested: 22, total time: 3h7m55.324788244s (build: 1h53m5.869791879s, test: 1h12m26.080159981s) the crash already happened on the oldest tested release commit msg: Linux 4.6 crash: WARNING in sysfs_warn_dup bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered disabled state device bridge_slave_0 entered promiscuous mode ------------[ cut here ]------------ WARNING: CPU: 0 PID: 5884 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: 0 PID: 5884 Comm: syz-executor.0 Not tainted 4.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 1ffffffff0d95756 ffff8800b98befb0 ffffffff82c74fc6 ffffffff85c81040 ffff8800b98bf088 ffffffff85d2bac0 ffffffff81922ccb ffff8800b98bf078 ffffffff8160cf4e 0000000041b58ab3 ffffffff868f1f61 ffffffff8160cd9f Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xe6/0x120 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.2+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+0x689/0x1360 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+0x88a/0xce0 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+0x455/0x660 net/netlink/af_netlink.c:1240 [] netlink_sendmsg+0x893/0xb40 net/netlink/af_netlink.c:1786 [] sock_sendmsg_nosec net/socket.c:612 [inline] [] sock_sendmsg+0xb5/0xf0 net/socket.c:622 [] SYSC_sendto+0x1c9/0x300 net/socket.c:1648 [] SyS_sendto+0x9/0x10 net/socket.c:1616 [] entry_SYSCALL_64_fastpath+0x23/0xc1 Kernel Offset: disabled