bisecting cause commit starting from 748d1c8a425ec529d541f082ee7a81f6a51fa120 building syzkaller on 3e8f6c27551f163a2fd2661e4b3cac126a5e7ef2 testing commit 748d1c8a425ec529d541f082ee7a81f6a51fa120 with gcc (GCC) 8.1.0 kernel signature: 5aa78b47b63438ecebac9498b529cf0a33ee04876c5f1b19e277a9a7d2e532ea all runs: crashed: WARNING in sta_info_insert_rcu testing release v5.8 testing commit bcf876870b95592b52519ed4aafcf9d95999bc9c with gcc (GCC) 8.1.0 kernel signature: 06a4465b036c01b9464f82602906487e5f43f687505fea37c0df89800212fe82 run #0: crashed: WARNING in corrupted run #1: crashed: WARNING in sta_info_insert_rcu run #2: crashed: WARNING in sta_info_insert_rcu run #3: crashed: WARNING in sta_info_insert_rcu run #4: crashed: WARNING in sta_info_insert_rcu run #5: crashed: WARNING in sta_info_insert_rcu run #6: crashed: WARNING in sta_info_insert_rcu run #7: crashed: WARNING in sta_info_insert_rcu run #8: crashed: WARNING in sta_info_insert_rcu run #9: crashed: WARNING in sta_info_insert_rcu testing release v5.7 testing commit 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 with gcc (GCC) 8.1.0 kernel signature: b9f790ec4d2c637835f5e7459cddc3e9bde402f4e9d8dea72d0ed641d75d9b9e all runs: crashed: WARNING in sta_info_insert_rcu testing release v5.6 testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.1.0 kernel signature: 07eaee35dc2e497dac2ca4af30768de72b406f3e4842fa07285b89a1105b6cf4 all runs: crashed: WARNING in sta_info_insert_rcu testing release v5.5 testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.1.0 kernel signature: 452351e257e8a0cc0748f5ef79e2673d8a416414dbfa67c39ded8d46ae415d30 all runs: crashed: WARNING in sta_info_insert_rcu testing release v5.4 testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0 kernel signature: bb778761c5ef6430c6eaa5685fbf33401a496bbffa08e69f398ce9d2484e1f47 all runs: crashed: WARNING in sta_info_insert_rcu testing release v5.3 testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0 kernel signature: 9a1d4f2fc01569bfccf5662e9c4e79a2e71455f21412380dc2a8ee9b972b40f4 all runs: crashed: WARNING in sta_info_insert_rcu testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0 kernel signature: b5ad3f2922691f5a58fd77477a89e62da8a4ba06098e187e9bedb79a92f7e30f all runs: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset testing release v5.1 testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0 kernel signature: cba8ed3a9401ac90c4563c482d0e502f97be441f35e6489e7110a0f48ff23245 run #0: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset run #1: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset run #2: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset run #3: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset run #4: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset run #5: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset run #6: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset run #7: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset run #8: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset run #9: crashed: WARNING in sta_info_insert_rcu testing release v5.0 testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0 kernel signature: b4409eaa12702e36eb6220cc3a933a7f7f475461d2a10b3cf652298dc72c3894 all runs: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset testing release v4.20 testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0 kernel signature: 3de6d1b4a72bfacbea8facb65cb2f1f272be8a0597ccda89d43a25464ceb1823 all runs: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset testing release v4.19 testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0 kernel signature: 6a7f165c5ac307deb9a5bed5a8ace42b8d6207b2c190f708177f665accbfc7aa all runs: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset testing release v4.18 testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.1.0 kernel signature: 22b58a42a53ee7260bd4e8d38f3ef9d1a70177c9afa8c7e2e19bfc331dcd6e96 all runs: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset testing release v4.17 testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.1.0 kernel signature: 7938144cb6355a37a96e17e5b4d5dd15197035756fa33386658d3f8738cd71ec all runs: basic kernel testing failed: timed out testing release v4.16 testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0 kernel signature: 84a4cc7363f83a715f365cbd7445e1f7c4e98fc856d3054f2859c2b45b400bf1 all runs: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset testing release v4.15 testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.1.0 ./arch/x86/include/asm/bootparam_utils.h:37: undefined reference to `__ubsan_handle_type_mismatch_v1' ./arch/x86/include/asm/bootparam_utils.h:39: undefined reference to `__ubsan_handle_type_mismatch_v1' ./arch/x86/include/asm/bootparam_utils.h:42: undefined reference to `__ubsan_handle_type_mismatch_v1' ./arch/x86/include/asm/bootparam_utils.h:45: undefined reference to `__ubsan_handle_type_mismatch_v1' ./arch/x86/include/asm/bootparam_utils.h:48: undefined reference to `__ubsan_handle_type_mismatch_v1' testing release v4.14 testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.1.0 ./arch/x86/include/asm/bootparam_utils.h:37: undefined reference to `__ubsan_handle_type_mismatch_v1' ./arch/x86/include/asm/bootparam_utils.h:39: undefined reference to `__ubsan_handle_type_mismatch_v1' ./arch/x86/include/asm/bootparam_utils.h:42: undefined reference to `__ubsan_handle_type_mismatch_v1' ./arch/x86/include/asm/bootparam_utils.h:45: undefined reference to `__ubsan_handle_type_mismatch_v1' ./arch/x86/include/asm/bootparam_utils.h:48: undefined reference to `__ubsan_handle_type_mismatch_v1' testing release v4.13 testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.1.0 ./arch/x86/include/asm/bootparam_utils.h:36: undefined reference to `__ubsan_handle_type_mismatch_v1' ./arch/x86/include/asm/bootparam_utils.h:38: undefined reference to `__ubsan_handle_type_mismatch_v1' ./arch/x86/include/asm/bootparam_utils.h:41: undefined reference to `__ubsan_handle_type_mismatch_v1' ./arch/x86/include/asm/bootparam_utils.h:44: undefined reference to `__ubsan_handle_type_mismatch_v1' ./arch/x86/include/asm/bootparam_utils.h:47: undefined reference to `__ubsan_handle_type_mismatch_v1' testing release v4.12 testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.1.0 arch/x86/entry/common.c:173: undefined reference to `__ubsan_handle_type_mismatch_v1' ./include/linux/compiler.h:254: undefined reference to `__ubsan_handle_type_mismatch_v1' ./include/linux/tracehook.h:190: undefined reference to `__ubsan_handle_type_mismatch_v1' ./include/linux/thread_info.h:60: undefined reference to `__ubsan_handle_type_mismatch_v1' ./include/trace/events/syscalls.h:17: undefined reference to `__ubsan_handle_type_mismatch_v1' testing release v4.11 testing commit a351e9b9fc24e982ec2f0e76379a49826036da12 with gcc (GCC) 7.3.0 kernel signature: 6700388f894a6f7291b1f55101d150933df315d488d68509b4547027c5bacc03 run #0: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #1: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #2: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #3: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #4: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #5: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #6: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #7: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #8: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #9: 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: 327c4f31943ac94ee5e133b6ae703066ca7a28280e497e20ef9006b4f5f628fa run #0: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #1: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #2: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #3: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #4: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #5: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #6: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #7: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #8: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le run #9: crashed: WARNING in sta_info_insert_rcu testing release v4.9 testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0 kernel signature: 8b6c20f0a11ada402e603481fcd457e2351880ee30948d9e61b321b608224b51 all runs: crashed: WARNING in sta_info_insert_rcu testing release v4.8 testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0 kernel signature: 30f74367bfb11296f080cfdedd4df5d2344e15c43635147516b19020b75a1d73 all runs: crashed: WARNING in sta_info_insert_rcu testing release v4.7 testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0 kernel signature: b683c4446406af32e6397142e5172895aee163830706622f66ebbb217ec9d66f run #0: crashed: UBSAN: undefined-behaviour in ip_idents_reserve run #1: crashed: UBSAN: undefined-behaviour in ip_idents_reserve run #2: crashed: UBSAN: undefined-behaviour in ip_idents_reserve run #3: crashed: UBSAN: undefined-behaviour in ip_idents_reserve run #4: crashed: KASAN: null-ptr-deref Read run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK testing release v4.6 testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0 kernel signature: efd38d60f31a93e2f15d5f0abffa698069140367ff11091c7879e203ffe3ee54 all runs: crashed: WARNING in sysfs_warn_dup revisions tested: 25, total time: 3h43m26.543536702s (build: 2h26m35.919421594s, test: 1h12m53.436423294s) the crash already happened on the oldest tested release commit msg: Linux 4.6 crash: WARNING in sysfs_warn_dup device bridge_slave_1 entered promiscuous mode bond0: Enslaving bond_slave_0 as an active interface with an up link bond0: Enslaving bond_slave_1 as an active interface with an up link IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready ------------[ cut here ]------------ WARNING: CPU: 1 PID: 5903 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: 5903 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 0000000000000000 ffff8800b9976ef0 ffffffff836c94e1 1ffffffff11345ba 0000000041b58ab3 ffffffff882802cf ffffffff836c9324 ffff8800b9976eb0 0000000000000000 ffff8800b9976eb8 ffffffff81586869 0000000000000512 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0x1bd/0x29c lib/dump_stack.c:51 [] panic+0x1bb/0x44a kernel/panic.c:152 [] __warn+0x194/0x1d0 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+0xeb/0x110 fs/sysfs/symlink.c:51 [] sysfs_do_create_link fs/sysfs/symlink.c:80 [inline] [] sysfs_create_link+0x3f/0xb0 fs/sysfs/symlink.c:92 [] device_add_class_symlinks drivers/base/core.c:891 [inline] [] device_add+0x47c/0x15d0 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+0x228/0x350 drivers/net/macvtap.c:1298 [] notifier_call_chain+0xac/0x280 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+0x4c/0x90 net/core/dev.c:1643 [] call_netdevice_notifiers net/core/dev.c:1659 [inline] [] register_netdevice+0x9d7/0x1310 net/core/dev.c:7027 [] macvlan_common_newlink+0xa15/0x1720 drivers/net/macvlan.c:1316 [] macvtap_newlink+0x128/0x230 drivers/net/macvtap.c:471 [] rtnl_newlink+0xe5e/0x1780 net/core/rtnetlink.c:2466 [] rtnetlink_rcv_msg+0x22b/0xc20 net/core/rtnetlink.c:3513 [] netlink_rcv_skb+0x1bb/0x2c0 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+0x419/0x630 net/netlink/af_netlink.c:1240 [] netlink_sendmsg+0x9a3/0xeb0 net/netlink/af_netlink.c:1786 [] sock_sendmsg_nosec net/socket.c:612 [inline] [] sock_sendmsg+0xdd/0x160 net/socket.c:622 [] SYSC_sendto net/socket.c:1648 [inline] [] SyS_sendto+0x1dd/0x2d0 net/socket.c:1616 [] entry_SYSCALL_64_fastpath+0x23/0xc1 Kernel Offset: disabled