bisecting cause commit starting from 5438dd45831ee33869779bd1919b05816ae4dbc9 building syzkaller on d5a3ae1f760e7cb2cd5a721d9645ae22eae114fe testing commit 5438dd45831ee33869779bd1919b05816ae4dbc9 with gcc (GCC) 8.1.0 kernel signature: f77da8e5f1ecca1eab44ff7adeea2ca670b995220155e4c27d35be588fc38588 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in fq_codel_enqueue testing release v5.8 testing commit bcf876870b95592b52519ed4aafcf9d95999bc9c with gcc (GCC) 8.1.0 kernel signature: 9cd5557d5bce21311950d7750930a3c2b461415e27a690abe34af3c0467258b4 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in fq_codel_enqueue testing release v5.7 testing commit 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 with gcc (GCC) 8.1.0 kernel signature: 76a6e21ec4a25a015d79fc9f96644335bc11bc5e332a849200650023af019f57 all runs: crashed: general protection fault in fq_codel_enqueue testing release v5.6 testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.1.0 kernel signature: 90e0eef1d18a6bb3d1f716c38b060203574469fec9febfc27cae3245797f3771 all runs: crashed: general protection fault in fq_codel_enqueue testing release v5.5 testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.1.0 kernel signature: 1332d9a2cba6d28dda44359977154ea40a03f8bef78feba30c798816db18223b all runs: crashed: general protection fault in fq_codel_enqueue testing release v5.4 testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0 kernel signature: 5da359e5c9d4d65bf507b17ca1eb2eb4d8c0828ff8e8129bd3eac881429c2f1f all runs: crashed: general protection fault in fq_codel_enqueue testing release v5.3 testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0 kernel signature: 52f154c0bfcc9e778883c5c0c1e5db99b098158c7ad08619bab9bb51e23572e5 all runs: crashed: general protection fault in fq_codel_enqueue testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0 kernel signature: 09c35b526b02148eef2305f3a9baa0984eba292dbcf4708d8d84765024da34f6 all runs: crashed: general protection fault in fq_codel_enqueue testing release v5.1 testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0 kernel signature: 737dd02423f0935840fb5a6156290af2eb058767c23b35c5762e5c4b1d96ed81 all runs: crashed: general protection fault in fq_codel_enqueue testing release v5.0 testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0 kernel signature: 9ab5c4c3ab73a5612e4b401b47ef8233c880d85c3dfe41174647f8c8cd015f5a all runs: crashed: general protection fault in fq_codel_enqueue testing release v4.20 testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0 kernel signature: c38ac391b15f96ddd6343c5af8c5cef8ffa8248cf65c6aba816f2d02a6a0ce2a all runs: crashed: general protection fault in fq_codel_enqueue testing release v4.19 testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0 kernel signature: 7597a25c9f810ec59a203e93abc055b3a61aed7a119115777c177ffe1024209d all runs: crashed: general protection fault in fq_codel_enqueue testing release v4.18 testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.1.0 kernel signature: c8d6a5fec4c10c87456ec9ac88ecac16d5e9dc20248f570a0debc4881b422080 all runs: crashed: general protection fault in fq_codel_enqueue testing release v4.17 testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.1.0 kernel signature: 832c4477e58da2ddcb961ac2b1d4e7aad53b6acfb008b75ab38a75a7b88466a4 all runs: crashed: general protection fault in fq_codel_enqueue testing release v4.16 testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0 kernel signature: 36f5b3db66c60a74afa8a5b88c43124fcd95b40b98884687d404f017d467c77e all runs: crashed: general protection fault in fq_codel_enqueue testing release v4.15 testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.1.0 kernel signature: a5c5a9c8890c2c22b13ea607922e10fd277aa9710c0745e878fe5d732001de9e all runs: crashed: general protection fault in fq_codel_enqueue testing release v4.14 testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.1.0 kernel signature: a1eba208f98373ae3f7fc702a3f7b18a2f359c972d7a1e8d4a0cc84d83a0775e all runs: crashed: general protection fault in fq_codel_enqueue testing release v4.13 testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.1.0 kernel signature: d59a251710e26802b394454404489ab1c515b1721c3ff80231257589ce437241 run #0: crashed: general protection fault in fq_codel_enqueue run #1: crashed: general protection fault in fq_codel_enqueue run #2: crashed: general protection fault in fq_codel_enqueue run #3: crashed: general protection fault in fq_codel_enqueue run #4: crashed: general protection fault in fq_codel_enqueue run #5: crashed: general protection fault in fq_codel_enqueue run #6: crashed: general protection fault in fq_codel_enqueue run #7: crashed: general protection fault in fq_codel_enqueue run #8: crashed: general protection fault in fq_codel_enqueue run #9: OK testing release v4.12 testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.1.0 kernel signature: 902a23a888987043bf368c5693a7541b120391923929ff5123ba602e0b679112 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: 50b12217253a6b559e943d54d51045b5bc9084265ff9ee06c18642e40c90431b 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: 12574178f3514a0274b28aaa7a137537d706fc34785feffded43224119756f04 all runs: crashed: general protection fault in fq_codel_enqueue testing release v4.9 testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0 kernel signature: b8ab8479344c433d58ce4b7d89ecc6e4ef1bf1cb5fdeec6cd7c96dcec37a9c47 run #0: crashed: general protection fault in fq_codel_enqueue run #1: crashed: general protection fault in fq_codel_enqueue run #2: crashed: general protection fault in fq_codel_enqueue run #3: crashed: general protection fault in fq_codel_enqueue run #4: crashed: general protection fault in fq_codel_enqueue run #5: OK run #6: OK run #7: OK run #8: OK run #9: crashed: WARNING in nf_unregister_net_hook testing release v4.8 testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0 kernel signature: 7398f868eb915fff4b1bb74b03011f2d7f9c53a7e6e76fe57db4787581d34d08 all runs: crashed: general protection fault in fq_codel_enqueue testing release v4.7 testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0 kernel signature: a59d90962b6a44159b67a4c50340803b6e699085326d59383bc6a5d9656b53f7 run #0: crashed: general protection fault in fq_codel_drop run #1: crashed: general protection fault in fq_codel_drop run #2: crashed: general protection fault in fq_codel_drop run #3: crashed: general protection fault in fq_codel_drop run #4: crashed: general protection fault in fq_codel_drop run #5: crashed: general protection fault in fq_codel_drop run #6: crashed: general protection fault in fq_codel_drop run #7: crashed: general protection fault in fq_codel_drop run #8: OK run #9: OK testing release v4.6 testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0 kernel signature: 7aebc77a9bf6bbc3073458ed1f9a15690cd60bb529784bf6b26100111af93c30 all runs: crashed: WARNING in sysfs_warn_dup revisions tested: 25, total time: 3h54m44.521701532s (build: 2h10m56.252965533s, test: 1h39m50.695067107s) the crash already happened on the oldest tested release commit msg: Linux 4.6 crash: WARNING in sysfs_warn_dup device bridge_slave_0 entered promiscuous mode 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 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 5899 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: 0 PID: 5899 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 ffff88012a886fc8 ffffffff82c65e52 ffffffff85c81040 ffff88012a8870a0 ffffffff85d2bb80 ffffffff8191bd7b 0000000000000009 ffff88012a887090 ffffffff8160d884 0000000041b58ab3 ffffffff868f8c5a 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