bisecting cause commit starting from f2850dd5ee015bd7b77043f731632888887689c7 building syzkaller on 84f4fc8afc9aedba4b3afa4bb76c3df6c6352c07 testing commit f2850dd5ee015bd7b77043f731632888887689c7 with gcc (GCC) 8.1.0 kernel signature: 249e0d1baf47b0649110e9c04f05c239614d3f009784ca23823519b2b26c20be all runs: crashed: KASAN: null-ptr-deref Read in do_con_trol testing release v5.5 testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.1.0 kernel signature: 120d9bf35927a6695835b763dc0a5e6121b2a15e77074bddb223da49b1e8b23a all runs: crashed: KASAN: null-ptr-deref Read in do_con_trol testing release v5.4 testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0 kernel signature: a3a3bdbb0ca4af547e588ff3fa3d8ac5483e1f2e90fd6e9f87e0f092f9406a65 all runs: crashed: KASAN: null-ptr-deref Read in do_con_trol testing release v5.3 testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0 kernel signature: a67c131e0e94d6d71bcf9081874e816bf629786d1ebd63ac4f05c5e1fd89556c all runs: crashed: KASAN: null-ptr-deref Read in do_con_trol testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0 kernel signature: 7294e5bcec83ea7c17f15252aa4aea5c2cd80ff2ae363d01bc704352df31cd93 all runs: crashed: KASAN: null-ptr-deref Read in do_con_trol testing release v5.1 testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0 kernel signature: 13e07b74080a365bf0c9b5b5c9f3d2997c0e8e195f1b1c95c4db54c75656b10d all runs: crashed: KASAN: null-ptr-deref Read in do_con_trol testing release v5.0 testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0 kernel signature: ba4138ad1aba0a260bf1c9e53a3207bdb11f20335065a00ec8ca78148832f5a3 all runs: crashed: KASAN: null-ptr-deref Read in do_con_trol testing release v4.20 testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0 kernel signature: c46117560eb1a087ce9fc7a1d61aa45f716a024ba4f0ad5c9dd512f6a916fe6c all runs: crashed: KASAN: null-ptr-deref Read in do_con_trol testing release v4.19 testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0 kernel signature: 041027406334a89d12c408d00ced7841ffd303de069f55a40bd6a761658f7f66 all runs: crashed: KASAN: null-ptr-deref Read in do_con_trol testing release v4.18 testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.1.0 kernel signature: 9e7b00d8344e1453e75bd5d81e6d487fb61aa7298546824ce092eef15baf27dd all runs: crashed: KASAN: null-ptr-deref Read in do_con_trol testing release v4.17 testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.1.0 kernel signature: 72b4f0d923e7769c02724f6a97086567680009ccaa3e0999acda3479111e6453 all runs: crashed: KASAN: null-ptr-deref Read in do_con_trol testing release v4.16 testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0 kernel signature: 03c769520b54f1309dd165e06fe06c4bd7bba7c69c52a720bc78a8a1a4bdac94 all runs: crashed: KASAN: null-ptr-deref Read in do_con_trol testing release v4.15 testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.1.0 kernel signature: 90de8c5d0eef2bffc6c6b13d5a2fd950c8ca704b5598aad7dcbadb91b6eb9d26 all runs: crashed: KASAN: null-ptr-deref Read in do_con_trol testing release v4.14 testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.1.0 kernel signature: be4d17a0331db89a4edcd793e2f67a27d34df5c5fd53f385f38ec4bcc9fdb80e all runs: crashed: KASAN: null-ptr-deref Read in do_con_trol testing release v4.13 testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.1.0 kernel signature: 97946d1ea889e2d626ab91bd5a0f0822391f6184e1922c65fb4d6eff2f3d917d all runs: crashed: general protection fault in do_con_trol testing release v4.12 testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.1.0 kernel signature: 540022096a539fe41e90b0ff4849656e113d2984058a98154efa8b7fae16c522 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: 3f058e4e7aa07c46204af854c0d8f9dd9d789587d7e1c5f5f3beca653f805626 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: 409d0dd87dd7ffefbc81051807d90bdfd07220e233a4ba7d3dbe86b15492fb51 all runs: crashed: general protection fault in do_con_trol testing release v4.9 testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0 kernel signature: 6fe24b2663b8f69e5a1d590dc97f4a008331901078df0cf7a1c850101b43d81f all runs: crashed: general protection fault in do_con_trol testing release v4.8 testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0 kernel signature: 143abd48626454e406287b62f47ab13bf398ffd24a8d2ead6488ebca32490321 all runs: crashed: general protection fault in do_con_trol testing release v4.7 testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0 kernel signature: 29f14e619757c9bc484bbbaf61a1de03b2708cbe6cd864e4648db743a5797456 all runs: crashed: general protection fault in do_con_trol testing release v4.6 testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0 kernel signature: 87329c27253444d7afc153462fd1ad8f9953d7d5dd7fe370c36110baa27fc296 all runs: crashed: WARNING in sysfs_warn_dup revisions tested: 22, total time: 3h16m54.206035481s (build: 1h59m24.304301824s, test: 1h15m5.268557343s) 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 bond0: Enslaving bond_slave_0 as an active interface with an up link IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready bond0: Enslaving bond_slave_1 as an active interface with an up link ------------[ cut here ]------------ WARNING: CPU: 1 PID: 7055 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: 7055 Comm: syz-executor.1 Not tainted 4.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 1ffffffff0d95756 ffff8800b6fa6fb0 ffffffff82c74fc6 ffffffff85c81040 ffff8800b6fa7088 ffffffff85d2bac0 ffffffff81922ccb ffff8800b6fa7078 ffffffff8160cf4e 0000000041b58ab3 ffffffff868f2161 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