bisecting cause commit starting from a0ba26f37ea04e025a793ef5e5ac809221728ecb
building syzkaller on 05736b290dd5af17adbb0fb5ea67405a0167a7c8
testing commit a0ba26f37ea04e025a793ef5e5ac809221728ecb with gcc (GCC) 8.1.0
kernel signature: f779eb9d7c4dddf6cc1232baf665ff8a5d31823cf7afc481d81530d36787493e
all runs: crashed: WARNING in ip_rt_bug
testing release v5.5
testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.1.0
kernel signature: a215524eb825244dee2455c861411153483aea1bfcde176029d81f0b16db2606
all runs: crashed: WARNING in ip_rt_bug
testing release v5.4
testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0
kernel signature: e2d11424afabdd94be41481656a62cd9358176e24f637f4ff1bd901244a33b58
all runs: crashed: WARNING in ip_rt_bug
testing release v5.3
testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0
kernel signature: 68c26ae6ab3727a7319375215a6525ac00739333a870f0b21bc3c6f158101f34
all runs: crashed: WARNING in ip_rt_bug
testing release v5.2
testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0
kernel signature: 8e7b7a5cbe220c3fb4001cace8f7416209232817bb34050782ff2b1f09ce4890
all runs: crashed: WARNING in ip_rt_bug
testing release v5.1
testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0
kernel signature: e63ef4de7f53733feee8ce04a4e3d86eb18a3a7d40babc77138fd50c17546ef9
all runs: crashed: WARNING in ip_rt_bug
testing release v5.0
testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0
kernel signature: a39faf809af777a61e0bf57f75f74b420e940dd5b553e7f395e53f1423c34a43
run #0: crashed: WARNING in ip_rt_bug
run #1: crashed: WARNING in corrupted
run #2: crashed: WARNING in ip_rt_bug
run #3: crashed: WARNING in ip_rt_bug
run #4: crashed: WARNING in ip_rt_bug
run #5: crashed: WARNING in corrupted
run #6: crashed: WARNING in corrupted
run #7: crashed: WARNING in corrupted
run #8: crashed: WARNING in corrupted
run #9: crashed: WARNING in ip_rt_bug
testing release v4.20
testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0
kernel signature: 9d9815a0564a867c71b6da4c39cffbbe3698f743990c61f1b6ba1d984226e344
run #0: crashed: WARNING in ip_rt_bug
run #1: crashed: WARNING in corrupted
run #2: crashed: WARNING in ip_rt_bug
run #3: crashed: WARNING in ip_rt_bug
run #4: crashed: WARNING in ip_rt_bug
run #5: crashed: WARNING in ip_rt_bug
run #6: crashed: WARNING in ip_rt_bug
run #7: crashed: WARNING in ip_rt_bug
run #8: crashed: WARNING in ip_rt_bug
run #9: crashed: WARNING in ip_rt_bug
testing release v4.19
testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0
kernel signature: adc3ca33c900261830c9c9e39fb1d4f33688badd9e37689c8383553d5f36c093
run #0: crashed: WARNING in corrupted
run #1: crashed: WARNING in corrupted
run #2: crashed: WARNING in corrupted
run #3: crashed: WARNING in corrupted
run #4: crashed: WARNING in corrupted
run #5: crashed: WARNING in corrupted
run #6: crashed: WARNING in ip_rt_bug
run #7: crashed: WARNING in corrupted
run #8: crashed: WARNING in corrupted
run #9: crashed: WARNING in corrupted
testing release v4.18
testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.1.0
kernel signature: 1e86b644b4a8e157f023631daba822231ce27866378b8f2469faed2bcff19768
run #0: crashed: WARNING in corrupted
run #1: crashed: WARNING in ip_rt_bug
run #2: crashed: WARNING in ip_rt_bug
run #3: crashed: WARNING in ip_rt_bug
run #4: crashed: WARNING in ip_rt_bug
run #5: crashed: WARNING in ip_rt_bug
run #6: crashed: WARNING in ip_rt_bug
run #7: crashed: WARNING in ip_rt_bug
run #8: crashed: WARNING in ip_rt_bug
run #9: crashed: WARNING in ip_rt_bug
testing release v4.17
testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.1.0
kernel signature: 6a32dddfd5191f3da869e68f68b0f29b511b8176a0daf9fc882094c4d39f4e23
run #0: crashed: WARNING in ip_rt_bug
run #1: crashed: WARNING in corrupted
run #2: crashed: WARNING in ip_rt_bug
run #3: crashed: WARNING in ip_rt_bug
run #4: crashed: WARNING in ip_rt_bug
run #5: crashed: WARNING in ip_rt_bug
run #6: crashed: WARNING in corrupted
run #7: crashed: WARNING in corrupted
run #8: crashed: WARNING in corrupted
run #9: crashed: WARNING in corrupted
testing release v4.16
testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0
kernel signature: 6e66d874c8e27536d6736050815ab6cf5d88ba863de22cc34130ac29dadcb7e4
run #0: crashed: WARNING in corrupted
run #1: crashed: WARNING in corrupted
run #2: crashed: WARNING in ip_rt_bug
run #3: crashed: WARNING in ip_rt_bug
run #4: crashed: WARNING in ip_rt_bug
run #5: crashed: WARNING in ip_rt_bug
run #6: crashed: WARNING in ip_rt_bug
run #7: crashed: WARNING in corrupted
run #8: crashed: WARNING in corrupted
run #9: crashed: WARNING in corrupted
testing release v4.15
testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.1.0
kernel signature: a3e83630fd964463b87359a972658176ff70f2dfaaa05e7764f4dcf9d2fc9da6
run #0: crashed: WARNING in ip_rt_bug
run #1: crashed: WARNING in corrupted
run #2: crashed: WARNING in ip_rt_bug
run #3: crashed: WARNING in corrupted
run #4: crashed: WARNING in corrupted
run #5: crashed: WARNING in ip_rt_bug
run #6: crashed: WARNING in corrupted
run #7: crashed: WARNING in ip_rt_bug
run #8: crashed: WARNING in ip_rt_bug
run #9: crashed: WARNING in ip_rt_bug
testing release v4.14
testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.1.0
kernel signature: ee34e2cc0a3dd0fb99bd073fc65dfaa8f16814dbc03d77f2e867be63694c2160
run #0: crashed: WARNING in ip_rt_bug
run #1: crashed: WARNING in ip_rt_bug
run #2: crashed: WARNING in corrupted
run #3: crashed: WARNING in ip_rt_bug
run #4: crashed: WARNING in corrupted
run #5: crashed: WARNING in ip_rt_bug
run #6: crashed: WARNING in ip_rt_bug
run #7: crashed: WARNING in ip_rt_bug
run #8: crashed: WARNING in ip_rt_bug
run #9: crashed: WARNING in ip_rt_bug
testing release v4.13
testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.1.0
kernel signature: dc67e745df4693298609d7edc234a19198265bc1596bee9711ce28400c24c645
run #0: crashed: WARNING in ip_rt_bug
run #1: crashed: WARNING in corrupted
run #2: crashed: WARNING in corrupted
run #3: crashed: WARNING in ip_rt_bug
run #4: crashed: WARNING in ip_rt_bug
run #5: crashed: WARNING in ip_rt_bug
run #6: crashed: WARNING in corrupted
run #7: crashed: WARNING in ip_rt_bug
run #8: crashed: WARNING in ip_rt_bug
run #9: crashed: WARNING in ip_rt_bug
testing release v4.12
testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.1.0
kernel signature: 897844794a69a16b2b3ea88a5ba5f4e0011bfb385740c38a98b6c11e40157966
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: f669bc8ea0f82999b5d633929fa3760ddbee6b53cc22cb35a909cb0bc7495a60
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: bc1559b1eb72259c998dff24ff2e7b6630b27061dd15f974a8a5b1152f941bb1
run #0: crashed: WARNING in ip_rt_bug
run #1: crashed: WARNING in ip_rt_bug
run #2: crashed: WARNING in corrupted
run #3: crashed: WARNING in ip_rt_bug
run #4: crashed: WARNING in ip_rt_bug
run #5: crashed: WARNING in ip_rt_bug
run #6: crashed: WARNING in ip_rt_bug
run #7: crashed: WARNING in ip_rt_bug
run #8: crashed: WARNING in ip_rt_bug
run #9: crashed: WARNING in corrupted
testing release v4.9
testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0
kernel signature: 1e3557fe2b9595a4b65c2afe95d56a9f88410d28fba96e8a276cc3dbaffd4b39
run #0: crashed: WARNING in ip_rt_bug
run #1: crashed: WARNING in ip_rt_bug
run #2: crashed: WARNING in ip_rt_bug
run #3: crashed: WARNING in ip_rt_bug
run #4: crashed: WARNING in ip_rt_bug
run #5: crashed: WARNING in corrupted
run #6: crashed: WARNING in ip_rt_bug
run #7: crashed: WARNING in corrupted
run #8: crashed: WARNING in ip_rt_bug
run #9: crashed: WARNING in ip_rt_bug
testing release v4.8
testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0
kernel signature: eab8a9005485bff6afe09c17312de8abc30670b15e707466d5193032425963da
run #0: crashed: WARNING in ip_rt_bug
run #1: crashed: WARNING in ip_rt_bug
run #2: crashed: WARNING in ip_rt_bug
run #3: crashed: WARNING in ip_rt_bug
run #4: crashed: WARNING in ip_rt_bug
run #5: crashed: WARNING in ip_rt_bug
run #6: crashed: WARNING in ip_rt_bug
run #7: crashed: WARNING in ip_rt_bug
run #8: crashed: WARNING in corrupted
run #9: crashed: WARNING in ip_rt_bug
testing release v4.7
testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0
kernel signature: 61633013e15cc1084e678025045506dea4f34df319c93c5ce7667469597e1245
all runs: crashed: WARNING in ip_rt_bug
testing release v4.6
testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0
kernel signature: 78e1e9b7442de6968f1315329ad0879345820c373abbf03835f55ac7deaacbbe
all runs: crashed: WARNING in sysfs_warn_dup
revisions tested: 22, total time: 3h6m46.014421631s (build: 1h52m45.301947421s, test: 1h11m47.397508459s)
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): hsr_slave_0: link is not ready
bond0: Enslaving bond_slave_0 as an active interface with an up link
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5888 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: 5888 Comm: syz-executor.4 Not tainted 4.6.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 1ffffffff0d95756 ffff8800b9d4efb0 ffffffff82c74fc6 ffffffff85c81040
 ffff8800b9d4f088 ffffffff85d2bac0 ffffffff81922ccb ffff8800b9d4f078
 ffffffff8160cf4e 0000000041b58ab3 ffffffff868f1f61 ffffffff8160cd9f
Call Trace:
 [<ffffffff82c74fc6>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff82c74fc6>] dump_stack+0xe6/0x120 lib/dump_stack.c:51
 [<ffffffff8160cf4e>] panic+0x1af/0x348 kernel/panic.c:152
 [<ffffffff8133960d>] __warn+0x18d/0x1b0 kernel/panic.c:504
 [<ffffffff813396c2>] warn_slowpath_fmt+0x92/0xb0 kernel/panic.c:527
 [<ffffffff81922ccb>] sysfs_warn_dup+0x7b/0xa0 fs/sysfs/dir.c:30
 [<ffffffff81923561>] sysfs_do_create_link_sd.isra.2+0xd1/0xf0 fs/sysfs/symlink.c:51
 [<ffffffff819235c3>] sysfs_do_create_link fs/sysfs/symlink.c:80 [inline]
 [<ffffffff819235c3>] sysfs_create_link+0x43/0xb0 fs/sysfs/symlink.c:92
 [<ffffffff83547c79>] device_add_class_symlinks drivers/base/core.c:891 [inline]
 [<ffffffff83547c79>] device_add+0x689/0x1360 drivers/base/core.c:1086
 [<ffffffff83548cb8>] device_create_groups_vargs+0x1c8/0x220 drivers/base/core.c:1709
 [<ffffffff83548db8>] device_create_vargs drivers/base/core.c:1749 [inline]
 [<ffffffff83548db8>] device_create+0x88/0xa0 drivers/base/core.c:1785
 [<ffffffff838e6c74>] macvtap_device_event+0x1c4/0x2a0 drivers/net/macvtap.c:1298
 [<ffffffff8139f90b>] notifier_call_chain+0x8b/0x170 kernel/notifier.c:93
 [<ffffffff8139fa11>] __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 [<ffffffff8139fa11>] raw_notifier_call_chain+0x11/0x20 kernel/notifier.c:401
 [<ffffffff84941897>] call_netdevice_notifiers_info+0x47/0x80 net/core/dev.c:1643
 [<ffffffff849675ea>] call_netdevice_notifiers net/core/dev.c:1659 [inline]
 [<ffffffff849675ea>] register_netdevice+0x88a/0xce0 net/core/dev.c:7027
 [<ffffffff838df9c9>] macvlan_common_newlink+0x8b9/0x1090 drivers/net/macvlan.c:1316
 [<ffffffff838e582f>] macvtap_newlink+0xbf/0x110 drivers/net/macvtap.c:471
 [<ffffffff8499494b>] rtnl_newlink+0xd4b/0x1230 net/core/rtnetlink.c:2466
 [<ffffffff8498fcf2>] rtnetlink_rcv_msg+0x222/0x680 net/core/rtnetlink.c:3513
 [<ffffffff84b198d2>] netlink_rcv_skb+0x242/0x350 net/netlink/af_netlink.c:2277
 [<ffffffff8498fac5>] rtnetlink_rcv+0x25/0x30 net/core/rtnetlink.c:3519
 [<ffffffff84b184d5>] netlink_unicast_kernel net/netlink/af_netlink.c:1214 [inline]
 [<ffffffff84b184d5>] netlink_unicast+0x455/0x660 net/netlink/af_netlink.c:1240
 [<ffffffff84b18f73>] netlink_sendmsg+0x893/0xb40 net/netlink/af_netlink.c:1786
 [<ffffffff848f1815>] sock_sendmsg_nosec net/socket.c:612 [inline]
 [<ffffffff848f1815>] sock_sendmsg+0xb5/0xf0 net/socket.c:622
 [<ffffffff848f27e9>] SYSC_sendto+0x1c9/0x300 net/socket.c:1648
 [<ffffffff848f4ad9>] SyS_sendto+0x9/0x10 net/socket.c:1616
 [<ffffffff85b9b640>] entry_SYSCALL_64_fastpath+0x23/0xc1
Kernel Offset: disabled