bisecting cause commit starting from b2e2a818a01717ba15c74fd355f76822b81a95f6 building syzkaller on 99a9604483616177d7cd7d3e092ce42a3eaff74a testing commit b2e2a818a01717ba15c74fd355f76822b81a95f6 with gcc (GCC) 8.1.0 kernel signature: af50e966c381b854f77903d0d82cfb60cafd7af3fa44045fd6f90bba53652490 all runs: crashed: no output from test machine testing release v5.6 testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.1.0 kernel signature: 54106327c74860b457fea238feb1b78874433b72f27e0d2b4608ec5a70ab8cc1 all runs: crashed: no output from test machine testing release v5.5 testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.1.0 kernel signature: 1808a1c8328204660951a15b3fa98fd0824af4afbdea02d8dc61dddd854c1b9c all runs: crashed: no output from test machine testing release v5.4 testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0 kernel signature: fffdfff65385ccebdf39f528cb02c9039a6b408c81eeb63bbb360ded0bc8dd73 run #0: crashed: unexpected kernel reboot run #1: crashed: unexpected kernel reboot run #2: crashed: unexpected kernel reboot run #3: crashed: unexpected kernel reboot run #4: crashed: unexpected kernel reboot run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v5.3 testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0 kernel signature: 73ad68abfca0cddcebe60b47741505eecb72639b16f8f9b049704a8f82f59140 run #0: crashed: general protection fault in do_syscall_64 run #1: crashed: unexpected kernel reboot run #2: crashed: unexpected kernel reboot run #3: crashed: unexpected kernel reboot run #4: crashed: unexpected kernel reboot run #5: crashed: unexpected kernel reboot run #6: crashed: unexpected kernel reboot run #7: crashed: unexpected kernel reboot run #8: crashed: unexpected kernel reboot run #9: crashed: no output from test machine testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0 kernel signature: 932a5c29320b261c608e0c3eb815d4569001fb2eef4d24b1b86a7c881267872f run #0: crashed: unexpected kernel reboot run #1: crashed: unexpected kernel reboot run #2: crashed: BUG: unable to handle kernel NULL pointer dereference in do_syscall_64 run #3: crashed: no output from test machine run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v5.1 testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0 kernel signature: 0826044860a60d429624ad524aca576070fb111021c468237b43254882e78981 run #0: crashed: unexpected kernel reboot run #1: crashed: BUG: sleeping function called from invalid context in __do_page_fault run #2: crashed: unexpected kernel reboot run #3: crashed: unexpected kernel reboot run #4: crashed: BUG: unable to handle kernel NULL pointer dereference in do_syscall_64 run #5: crashed: unexpected kernel reboot run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v5.0 testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0 kernel signature: b82d9be75b6b7b62ff125b2aa6953118160dccfd70393f8e0650913bfa07f644 run #0: crashed: unexpected kernel reboot run #1: crashed: unexpected kernel reboot run #2: crashed: unexpected kernel reboot run #3: crashed: unexpected kernel reboot run #4: crashed: unexpected kernel reboot run #5: crashed: unexpected kernel reboot run #6: crashed: unexpected kernel reboot run #7: crashed: unexpected kernel reboot run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.20 testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0 kernel signature: 96f1f3cbaa8bc112f3656f7249c1df2b8d23df20a66b6b1acfff5306a9843708 run #0: crashed: unexpected kernel reboot run #1: crashed: unexpected kernel reboot run #2: crashed: unexpected kernel reboot run #3: crashed: unexpected kernel reboot run #4: crashed: unexpected kernel reboot run #5: crashed: unexpected kernel reboot run #6: crashed: unexpected kernel reboot run #7: crashed: unexpected kernel reboot run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.19 testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0 kernel signature: 178ab4cf7b5759e266ccd8d2c6a882aa61473f75e2393cce615d469ccc5b1df1 run #0: crashed: unexpected kernel reboot run #1: crashed: unexpected kernel reboot run #2: crashed: unexpected kernel reboot run #3: crashed: unexpected kernel reboot run #4: crashed: unexpected kernel reboot run #5: crashed: unexpected kernel reboot run #6: crashed: unexpected kernel reboot run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.18 testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.1.0 kernel signature: 0c515ec5029c5155ed36cef83a5446b8c329db8e826116247c9593740c696450 run #0: crashed: unexpected kernel reboot run #1: crashed: unexpected kernel reboot run #2: crashed: unexpected kernel reboot run #3: crashed: unexpected kernel reboot run #4: crashed: unexpected kernel reboot run #5: crashed: general protection fault in do_syscall_64 run #6: crashed: unexpected kernel reboot run #7: crashed: unexpected kernel reboot run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.17 testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.1.0 kernel signature: 66cb24a584c81d7728763d00b7032cfa0a63ec688c313c32d9305871e8f2cde5 run #0: crashed: unexpected kernel reboot run #1: crashed: unexpected kernel reboot run #2: crashed: unexpected kernel reboot run #3: crashed: unexpected kernel reboot run #4: crashed: unexpected kernel reboot run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.16 testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0 kernel signature: c83983d943165bc6bee003717d78aa5ab143a127694c7ed2fa4564d69d3a8596 run #0: crashed: unexpected kernel reboot run #1: crashed: unexpected kernel reboot run #2: crashed: unexpected kernel reboot run #3: crashed: unexpected kernel reboot run #4: crashed: unexpected kernel reboot run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.15 testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.1.0 kernel signature: 3f65e6d898b156971adea1d74b97628ef60f24444bf847f1b3f27feb397f16fc run #0: crashed: unexpected kernel reboot run #1: crashed: unexpected kernel reboot run #2: crashed: unexpected kernel reboot run #3: crashed: unexpected kernel reboot run #4: crashed: unexpected kernel reboot run #5: crashed: unexpected kernel reboot run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.14 testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.1.0 kernel signature: 0dc279d81a39ae5a35a61e49b3516380588a2b68f9f0631f12c247bdb1a129ad all runs: crashed: unexpected kernel reboot testing release v4.13 testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.1.0 kernel signature: b1b102ee68e0ff244f7efbcb8866e025850b31af4af90a3deb205ee1ff2088dd all runs: crashed: unexpected kernel reboot testing release v4.12 testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.1.0 kernel signature: 69890e1d37cd38ad33768120e905a5cd2d6db4f21ae26b3a076cf27798e3cab7 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: bbb780cde72a0abe7c63f10b40ca8a2f02e7c6c07c22951ff01032c0b0e588ba 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: cb8809ffb49242dda8353188d0fef1fc8cebd6e5a0527ae1eeb9aeb29e348a03 all runs: crashed: unexpected kernel reboot testing release v4.9 testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0 kernel signature: 1ee0c8b39ec4035f9e0c439d1a4ea4ff23943b2388a79fe71596e8fb48aa9a0a all runs: crashed: unexpected kernel reboot testing release v4.8 testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0 kernel signature: 8ce5b23a0fa30ada5a6ae778a1987cb2dd97beb56f44489ac050f8a4d3dbda0d run #0: crashed: BUG: unable to handle kernel paging request in syscall_trace_enter run #1: crashed: unexpected kernel reboot run #2: crashed: unexpected kernel reboot run #3: crashed: unexpected kernel reboot run #4: crashed: unexpected kernel reboot run #5: crashed: unexpected kernel reboot run #6: crashed: unexpected kernel reboot run #7: crashed: unexpected kernel reboot run #8: crashed: unexpected kernel reboot run #9: crashed: no output from test machine testing release v4.7 testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0 kernel signature: d1868d306dfb4a940aaa3f7599690821a264cd90cf61559adf75ad6c25062841 run #0: crashed: unexpected kernel reboot run #1: crashed: unexpected kernel reboot run #2: crashed: unexpected kernel reboot run #3: crashed: BUG: sleeping function called from invalid context in __do_page_fault run #4: crashed: unexpected kernel reboot run #5: crashed: unexpected kernel reboot run #6: crashed: unexpected kernel reboot run #7: crashed: BUG: sleeping function called from invalid context in __do_page_fault run #8: crashed: unexpected kernel reboot run #9: crashed: no output from test machine testing release v4.6 testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0 kernel signature: 600efe239a9dc874ca7133b5d514e75c4e782bd7873d864a9bbe5804842eeff1 all runs: crashed: WARNING in sysfs_warn_dup revisions tested: 23, total time: 4h39m24.910371517s (build: 2h7m41.021179876s, test: 2h29m0.450506817s) the crash already happened on the oldest tested release commit msg: Linux 4.6 crash: WARNING in sysfs_warn_dup IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready 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: 1 PID: 5915 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: 5915 Comm: syz-executor.2 Not tainted 4.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 ffff8800b2f46fc8 ffffffff82c65932 ffffffff85c81040 ffff8800b2f470a0 ffffffff85d2bb00 ffffffff8191b86b 0000000000000009 ffff8800b2f47090 ffffffff8160d374 0000000041b58ab3 ffffffff868f058a 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