bisecting cause commit starting from eff48ddeab782e35e58ccc8853f7386bbae9dec4 building syzkaller on 3e8f6c27551f163a2fd2661e4b3cac126a5e7ef2 testing commit eff48ddeab782e35e58ccc8853f7386bbae9dec4 with gcc (GCC) 8.1.0 kernel signature: 251f813ff67da80e24eedf798849aef6a97639b95b016598499710e021d12ab1 all runs: crashed: WARNING in sta_info_insert_rcu testing release v5.8 testing commit bcf876870b95592b52519ed4aafcf9d95999bc9c with gcc (GCC) 8.1.0 kernel signature: 235085a92ae387e2a69134bb08df2e2b4516f38dc6a5f9d4182edf63e1298ab2 run #0: crashed: WARNING in sta_info_insert_rcu 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 corrupted 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: 917d2bff89e19ea617d1c5cb91d89d421162fd8b650a6e260e360493b9750d7e all runs: crashed: WARNING in sta_info_insert_rcu testing release v5.6 testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.1.0 kernel signature: c55012ed3b07f216dd8497ad630576e03ffff91f5b77636aec4acb02d66dd2d7 all runs: crashed: WARNING in sta_info_insert_rcu testing release v5.5 testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.1.0 kernel signature: 76e4e71f02f172de21e7ca039c0ee146792b0636c9ee16ad190495b78e7cbe21 all runs: crashed: WARNING in sta_info_insert_rcu testing release v5.4 testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0 kernel signature: df47296a5a945dde3380ad7c596f5cc0c7fe3100057878b0e80d622e23d9320a all runs: crashed: WARNING in sta_info_insert_rcu testing release v5.3 testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0 kernel signature: e627924bcb8f78a23cca65c4327aa89ebcff153a8ce1c3fd765e7605c41b4ff6 all runs: crashed: WARNING in sta_info_insert_rcu testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0 kernel signature: 8ee305fb051db27296ab201b1da7ba83945817c83c94cfc5181063cce7e90bba 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: 0aacba3f5fcc1e24e5144ad9d0ced37e334621bab02e85623e0746441492316b all runs: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset testing release v5.0 testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0 kernel signature: 7313afd72d5ba05bd552c9fcb01518961a7b038bbe35fa53c6b67eff50e25a48 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: e6b9c15e67dddf1dafd392569606345627efff55b56c55eb18c6208e6d02ba2b 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 v4.19 testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0 kernel signature: f035564960dbcd75735b47a19d8129a919cfcaafee1a52c612190dc9c2ae7e1e 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: 59adbcca08c97ebf15e8f9cec209cfd37324b8ce864fc03d6042aad8f6fc3c49 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: 8bd08c4ab037c095439dfe503f9c917a1cb54815d4952a7c903b4746abf9917e run #0: basic kernel testing failed: UBSAN: undefined-behaviour in handle_null_ptr_deref 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 handle_null_ptr_deref 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: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset testing release v4.16 testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0 kernel signature: 3dfd087700df06466cd7aef75928d5fdd4a704e3a546aff012db435c11885eee 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 handle_null_ptr_deref run #6: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset run #7: basic kernel testing failed: UBSAN: undefined-behaviour in handle_null_ptr_deref run #8: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_vq_reset run #9: 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: e69cd4294d2b4e499366efc989a2f6d631fcec1c0c5ba5e11343defefbc4ac18 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: f9a1c9ceee30f98fc8c6d20fa84f227d851a48b5564139c6fae85118413791c1 all runs: basic kernel testing failed: UBSAN: undefined-behaviour in vhost_init_is_le testing release v4.9 testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0 kernel signature: 0690a9e323d28345592beb7aa83b7640a15350f613b905d4be1d80d54229535e run #0: crashed: WARNING in sta_info_insert_rcu 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 corrupted run #9: crashed: WARNING in sta_info_insert_rcu testing release v4.8 testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0 kernel signature: a7a9c9df4fb535f3779ae609ad345254f764390f9a1103fc8f07563b22176f0a all runs: crashed: WARNING in sta_info_insert_rcu testing release v4.7 testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0 kernel signature: 874a39fdf73b6fa316628ec9c87470128f50f195418ee908a8d0ebd78f3343d0 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: UBSAN: undefined-behaviour in ip_idents_reserve 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: d487c5a5767fc64f8a19521a55333d44ff68093b904ca21db0ad566a68d9d1ed all runs: crashed: WARNING in sysfs_warn_dup revisions tested: 25, total time: 3h37m58.680006574s (build: 2h26m5.818062842s, test: 1h7m55.661249645s) 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: 5907 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: 5907 Comm: syz-executor.5 Not tainted 4.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 ffff8800b2716ef0 ffffffff836c94e1 1ffffffff11345ba 0000000041b58ab3 ffffffff882802cf ffffffff836c9324 ffff8800b2716eb0 0000000000000000 ffff8800b2716eb8 ffffffff81586869 0000000000000540 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