bisecting cause commit starting from 65f0d2414b7079556fbbcc070b3d1c9f9587606d building syzkaller on 269d24e857a757d09a898086a2fa6fa5d827c3e1 testing commit 65f0d2414b7079556fbbcc070b3d1c9f9587606d with gcc (GCC) 8.1.0 kernel signature: 87a7799bb203f19acdacb4673afefbc2d40e5dd34fca1794a4adfaad69436f02 all runs: crashed: WARNING in memdup_user_nul testing release v5.10 testing commit 2c85ebc57b3e1817b6ce1a6b703928e113a90442 with gcc (GCC) 8.1.0 kernel signature: 5035332b8f978c13779dd8be0ba1e4ce5debb9716b94f5b4b7dce31f48ab366b all runs: crashed: WARNING in memdup_user_nul testing release v5.9 testing commit bbf5c979011a099af5dc76498918ed7df445635b with gcc (GCC) 8.1.0 kernel signature: 2f0cdf8aed36b324203f4cc1de1d4131b2298d9a637c07231f4713cb001a6b91 all runs: crashed: WARNING in memdup_user_nul testing release v5.8 testing commit bcf876870b95592b52519ed4aafcf9d95999bc9c with gcc (GCC) 8.1.0 kernel signature: e83a67d5838f5deb0028c90a4cb7c18a3b7a965c266778c56c081490bd927d3c run #0: crashed: WARNING in memdup_user_nul run #1: crashed: WARNING in memdup_user_nul run #2: crashed: WARNING in memdup_user_nul run #3: crashed: WARNING in memdup_user_nul run #4: crashed: WARNING in memdup_user_nul run #5: crashed: WARNING in memdup_user_nul run #6: crashed: WARNING in memdup_user_nul run #7: crashed: WARNING in memdup_user_nul run #8: crashed: WARNING in memdup_user_nul run #9: boot failed: can't ssh into the instance testing release v5.7 testing commit 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 with gcc (GCC) 8.1.0 kernel signature: c058fd59186be6bc0d55f520f237d24ae012c24d54deae6dcf602bb77313d941 all runs: crashed: WARNING in memdup_user_nul testing release v5.6 testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.1.0 kernel signature: 504766679c547653d15adbae15ac2db4a908b85f3e0d4c23b00526d43ff6f350 all runs: crashed: WARNING in memdup_user_nul testing release v5.5 testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.1.0 kernel signature: 1f9202d0c45623ca8f7f3cf7f0657516cdb12510634c9ad5b4808f54aca4cc3a all runs: crashed: WARNING in memdup_user_nul testing release v5.4 testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0 kernel signature: 127ffbddd34a6f55760997d26c5f9fce5e23f3d1b68b2eb2447b184b3c59958c all runs: crashed: WARNING in memdup_user_nul testing release v5.3 testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0 kernel signature: 67dd518639c5e2e080e7a9ebc7bc7d8e5d264dc0dfb8d14df6c513ecadb8ec73 all runs: crashed: WARNING in memdup_user_nul testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0 kernel signature: 9438469d4edb032a2109f93c2ee4862b41c482da3c4049fe678bc636cbb52007 all runs: crashed: WARNING in memdup_user_nul testing release v5.1 testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0 kernel signature: 20b979a4c2d3b41adc8eeb85bfcd328a2715cd932fb180b00ad8cf80b4712dff all runs: crashed: WARNING in memdup_user_nul testing release v5.0 testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0 kernel signature: 80b5e353e1895803871f3393bbaf0c59eef79e5f86529b2080952b02853f5a11 all runs: crashed: WARNING in memdup_user_nul testing release v4.20 testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0 kernel signature: 1d4fd29296545d47e6083316e1f049bca2d3e9b058f9a18ce301717a51a67501 all runs: crashed: WARNING in memdup_user_nul testing release v4.19 testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0 kernel signature: 0d2d42507db9d6ca5d8f9f3273355307270a5386ec80b6e6d67e77fba11bd107 all runs: crashed: WARNING in memdup_user_nul testing release v4.18 testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.1.0 kernel signature: b8dc5ee22e1cbc7af12d64719a4c8d02236e41951dce384577837cbabce03de0 all runs: crashed: WARNING in memdup_user_nul testing release v4.17 testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.1.0 kernel signature: 87d6895157d49515710c6f04450a1c3f010c084d8f19aac848b9f4ce6248772d all runs: crashed: WARNING in memdup_user_nul testing release v4.16 testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0 kernel signature: 026694c3c3d6f67b46cbd4e4619f95f5221ca8f2d936989fe30304357ee9c307 all runs: crashed: WARNING in memdup_user_nul testing release v4.15 testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.1.0 kernel signature: 082b6350ff3211fdf3a2ffde3199c844fb224e5413f8af041ddff8af1c913ab7 all runs: crashed: WARNING in memdup_user_nul testing release v4.14 testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.1.0 kernel signature: 64ee029ef972cdbd3246ef2cefdd381f09750a29ad5725f9ea606c06da268f9c all runs: crashed: WARNING in memdup_user_nul testing release v4.13 testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.1.0 kernel signature: 00afce216c9c9fb6d3ca29c9bbdf9c2fd2258931e9aa00d12dbdaf03b8321106 all runs: crashed: WARNING in memdup_user_nul testing release v4.12 testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.1.0 kernel signature: a3758dca2bef61f7597bd6f2661ec4f45824e37e5dec99ee66c6f7a83afda858 all runs: basic kernel testing failed: 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: e40caaadb386728852a79b52b128f2832522b4266bdedf08b877a2c65cafee54 all runs: basic kernel testing failed: 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: b6f6f18cfcaeedcec769744d37af9659ff7865c1bc6115065c33f3dbf9d606e1 all runs: crashed: WARNING in memdup_user_nul testing release v4.9 testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0 kernel signature: 4131105ae0e9968191c58d0fb7327f4b59a555c15b9c485c8f7a2d80a0b7e7cc all runs: crashed: WARNING in memdup_user_nul testing release v4.8 testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0 kernel signature: 449a8fb25183c234121d400ea6eb79c8802fa1ee207cf3cbf5862a79d27a8c6e all runs: crashed: WARNING in memdup_user_nul testing release v4.7 testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0 kernel signature: 43b7a296b3742b097330b805a00290dd811e318f37558ac24cbf9a2ef1179c89 all runs: crashed: WARNING in alloc_kmem_pages testing release v4.6 testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0 kernel signature: 388d818384150ee7227450b91228191cf413189746729d1c3bba12a5e267c9ee all runs: crashed: WARNING in sysfs_warn_dup revisions tested: 27, total time: 3h37m29.16562812s (build: 2h10m18.00606643s, test: 1h23m21.010360839s) 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 disabled state device bridge_slave_1 entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready ------------[ cut here ]------------ WARNING: CPU: 1 PID: 7906 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: 7906 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 ffff8800b924efc8 ffffffff82da4dd2 ffffffff8667aec0 ffff8800b924f0a0 ffffffff8672c8c0 ffffffff818db72b 0000000000000009 ffff8800b924f090 ffffffff815c7a54 0000000041b58ab3 ffffffff87779893 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+0x6a1/0x1400 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