bisecting cause commit starting from 325d0eab4f31c6240b59d5b2b8042c88f59405b5 building syzkaller on 9564d2e9821aea842b6ab213174aabd4b578b039 testing commit 325d0eab4f31c6240b59d5b2b8042c88f59405b5 with gcc (GCC) 8.1.0 kernel signature: 309663ae56fdf99fa16ad0587fda47535176760ae1756c02e6d46b6148e52199 all runs: crashed: WARNING in f2fs_is_valid_blkaddr testing release v5.8 testing commit bcf876870b95592b52519ed4aafcf9d95999bc9c with gcc (GCC) 8.1.0 kernel signature: fe3dd42ed0cb4166ab8fbcc92eccea7d0d5874ea01296ee13a0a9a69ba6eb774 all runs: crashed: WARNING in f2fs_is_valid_blkaddr testing release v5.7 testing commit 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 with gcc (GCC) 8.1.0 kernel signature: a3a8193db9a54cdf56dfd0447d9de37f3a884cf0c1d6286bbba41ff9851645ec all runs: crashed: WARNING in f2fs_is_valid_blkaddr testing release v5.6 testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.1.0 kernel signature: 04e34b95881c7c43d47740aebb03fdd52ad74187c9037f86255edbcabf816619 all runs: crashed: WARNING in f2fs_is_valid_blkaddr testing release v5.5 testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.1.0 kernel signature: 2018fb790198d3893744dc952ea1da704533f662f251aaa741958b724787a800 all runs: crashed: WARNING in f2fs_is_valid_blkaddr testing release v5.4 testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0 kernel signature: db62c6cd82fcaedc504cf476a75cd38f8567ae5b29aceaf3cabc7043cd1b2cc7 all runs: crashed: WARNING in f2fs_is_valid_blkaddr testing release v5.3 testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0 kernel signature: 4a77e5169ca96d673057b1942bb4f4e07b493cb5903ce4acf54735b3d8cba641 all runs: crashed: WARNING in f2fs_is_valid_blkaddr testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0 kernel signature: c8c0f5f1f115dc0c7540da6eb5db28d42d49f402d31c7debaf86ac9c07f33e79 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: crashed: WARNING in f2fs_is_valid_blkaddr run #8: crashed: WARNING in f2fs_is_valid_blkaddr run #9: crashed: WARNING in f2fs_is_valid_blkaddr testing release v5.1 testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0 kernel signature: cd2aeeaaf01106c485434461c45ea50323352ae3525d9a1002ef8dc71020c8bf 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: 399d2260169d7679e655b5f45b0f66b1f46d7dfe57bf9b02a8d8156f6204b8ed 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 f2fs_is_valid_blkaddr testing release v4.20 testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0 kernel signature: 7ee817569b7fac1ab5392b022eb4afcfb0014dbf38a04c16b9f9340abf2e4efe 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: f22b54e25c9dd5cf5a3a02b24d8e3c973090ec6cd2d7e1d4affbe01efa642440 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: 38e3c932f3f3a36889e4d70a2191575bbdc7a2248802c23af469c2aca076c752 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: f6d59166f53e35f5c3714b066c7b207d77aac3890bc662f2dfe0195e565add5c 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 handle_null_ptr_deref 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: 0942c9d296e7284d980199753b1ee4186dfece3434d71429c12867feac720977 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 handle_null_ptr_deref 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: aa28a916dd041af585d192ce52c98fe10e9a08f24915b863588782ca883973d8 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: crashed: BUG: sleeping function called from invalid context in tap_get_minor run #8: crashed: BUG: sleeping function called from invalid context in tap_get_minor 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: e586e76ba53059d24a450e50ecacc84e64319ae9a0b6cd518c3d8b2297f16e11 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: kernel BUG at fs/f2fs/node.c:LINE! testing release v4.9 testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0 kernel signature: 8355c4297356cdb2b7bb804b90e2ac9abd8eb46ae559df5667c1978466d09be7 all runs: crashed: kernel BUG at fs/f2fs/node.c:LINE! testing release v4.8 testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0 kernel signature: 3c3cd826378b34cb1a1aa158ab9685b4eb92691c0a01b762c072501f93dc744e all runs: crashed: kernel BUG at fs/f2fs/node.c:LINE! testing release v4.7 testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0 kernel signature: bdca20d8132d31d3df5315ebf606bb030b4a0eb2c87a51fef01cd7f7901e573f run #0: crashed: kernel BUG at fs/f2fs/node.c:LINE! run #1: crashed: kernel BUG at fs/f2fs/node.c:LINE! run #2: crashed: kernel BUG at fs/f2fs/node.c:LINE! run #3: crashed: kernel BUG at fs/f2fs/node.c:LINE! run #4: crashed: kernel BUG at fs/f2fs/node.c:LINE! run #5: crashed: kernel BUG at fs/f2fs/node.c:LINE! run #6: crashed: kernel BUG at fs/f2fs/node.c:LINE! run #7: crashed: UBSAN: undefined-behaviour in ip_idents_reserve run #8: crashed: kernel BUG at fs/f2fs/node.c:LINE! run #9: crashed: kernel BUG at fs/f2fs/node.c:LINE! testing release v4.6 testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0 kernel signature: 4017423022650ec589dd51ca149bd10176c820dfa1dbf4a6cbf79314ea437755 all runs: crashed: WARNING in sysfs_warn_dup revisions tested: 25, total time: 3h39m3.328900417s (build: 2h32m15.700350125s, test: 1h1m23.18963782s) the crash already happened on the oldest tested release commit msg: Linux 4.6 crash: WARNING in sysfs_warn_dup bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_1 entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready ------------[ cut here ]------------ WARNING: CPU: 1 PID: 5895 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: 5895 Comm: syz-executor.3 Not tainted 4.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 ffff88012936eef0 ffffffff836c94e1 1ffffffff11345ba 0000000041b58ab3 ffffffff882802cf ffffffff836c9324 ffff88012936eeb0 0000000000000000 ffff88012936eeb8 ffffffff81586869 000000000000056e 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