bisecting cause commit starting from 189522da8b3a796d56d802e067d591d2ffff7f40
building syzkaller on 2e44d63e401ead7d7928c95a30d243b2de1a243b
testing commit 189522da8b3a796d56d802e067d591d2ffff7f40 with gcc (GCC) 8.1.0
kernel signature: ec75657950ce05794ac30644358b6ae5a8d27b957ce5e8aa1d2305368f3e6548
run #0: crashed: KASAN: use-after-free Read in get_block
run #1: crashed: KASAN: use-after-free Read in get_block
run #2: crashed: KASAN: use-after-free Read in get_block
run #3: crashed: KASAN: use-after-free Read in get_block
run #4: crashed: KASAN: use-after-free Read in get_block
run #5: crashed: KASAN: out-of-bounds Read in get_block
run #6: crashed: KASAN: use-after-free Read in get_block
run #7: crashed: KASAN: out-of-bounds Read in get_block
run #8: crashed: KASAN: use-after-free Read in get_block
run #9: crashed: KASAN: use-after-free Read in get_block
testing release v5.6
testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.1.0
kernel signature: a783ae8d9625bf38041a9af7c7ba6f70327a00f0bb73737cbdaf48184bdff4be
run #0: crashed: KASAN: use-after-free Read in get_block
run #1: crashed: KASAN: use-after-free Read in get_block
run #2: crashed: KASAN: use-after-free Read in get_block
run #3: crashed: KASAN: use-after-free Read in get_block
run #4: crashed: KASAN: use-after-free Read in get_block
run #5: crashed: KASAN: use-after-free Read in get_block
run #6: crashed: KASAN: use-after-free Read in get_block
run #7: crashed: KASAN: use-after-free Read in get_block
run #8: crashed: KASAN: out-of-bounds Read in get_block
run #9: crashed: KASAN: use-after-free Read in get_block
testing release v5.5
testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.1.0
kernel signature: fc0b935c02c3ee2820f2c71e4ff56788d24b11032cd766a4c48869ffd0f6e8ed
run #0: crashed: KASAN: use-after-free Read in get_block
run #1: crashed: KASAN: use-after-free Read in get_block
run #2: crashed: KASAN: use-after-free Read in get_block
run #3: crashed: KASAN: use-after-free Read in get_block
run #4: crashed: KASAN: use-after-free Read in get_block
run #5: crashed: KASAN: out-of-bounds Read in get_block
run #6: crashed: KASAN: use-after-free Read in get_block
run #7: crashed: KASAN: use-after-free Read in get_block
run #8: crashed: KASAN: out-of-bounds Read in get_block
run #9: crashed: KASAN: use-after-free Read in get_block
testing release v5.4
testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0
kernel signature: 8419fee687a174508fb9b3292c7fdfac5f5a634c461f01e087e75c0ba4b2c1f5
all runs: crashed: KASAN: use-after-free Read in get_block
testing release v5.3
testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0
kernel signature: b7e865df1975ea60c0f00098e09fa8623259ab3d8f92d71723aa4e5849f4727b
run #0: crashed: KASAN: use-after-free Read in get_block
run #1: crashed: KASAN: use-after-free Read in get_block
run #2: crashed: KASAN: use-after-free Read in get_block
run #3: crashed: KASAN: out-of-bounds Read in get_block
run #4: crashed: KASAN: use-after-free Read in get_block
run #5: crashed: KASAN: use-after-free Read in get_block
run #6: crashed: KASAN: use-after-free Read in get_block
run #7: crashed: KASAN: use-after-free Read in get_block
run #8: crashed: KASAN: out-of-bounds Read in get_block
run #9: crashed: KASAN: use-after-free Read in get_block
testing release v5.2
testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0
kernel signature: 4a0f69d2c54dfbf382f9dc3e397344051af9f15c23731bf6780e490976c8fb01
run #0: crashed: KASAN: use-after-free Read in get_block
run #1: crashed: KASAN: use-after-free Read in get_block
run #2: crashed: KASAN: use-after-free Read in get_block
run #3: crashed: KASAN: use-after-free Read in get_block
run #4: crashed: KASAN: out-of-bounds Read in get_block
run #5: crashed: KASAN: use-after-free Read in get_block
run #6: crashed: KASAN: use-after-free Read in get_block
run #7: crashed: KASAN: out-of-bounds Read in get_block
run #8: crashed: KASAN: slab-out-of-bounds Read in get_block
run #9: crashed: KASAN: use-after-free Read in get_block
testing release v5.1
testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0
kernel signature: 743dac506e145ae69ac6ec579faf137a15a28d3bc48ea659ab70d426b76dc0e5
run #0: crashed: KASAN: out-of-bounds Read in get_block
run #1: crashed: KASAN: use-after-free Read in get_block
run #2: crashed: KASAN: use-after-free Read in get_block
run #3: crashed: KASAN: use-after-free Read in get_block
run #4: crashed: KASAN: use-after-free Read in get_block
run #5: crashed: KASAN: out-of-bounds Read in get_block
run #6: crashed: KASAN: use-after-free Read in get_block
run #7: crashed: KASAN: use-after-free Read in get_block
run #8: crashed: KASAN: use-after-free Read in get_block
run #9: crashed: KASAN: use-after-free Read in get_block
testing release v5.0
testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0
kernel signature: 76b8405456d0c3c38261ffe4aafcf99787cbf894cc420ea0f2b79a0f2bb98b00
run #0: crashed: KASAN: use-after-free Read in get_block
run #1: crashed: KASAN: use-after-free Read in get_block
run #2: crashed: KASAN: use-after-free Read in get_block
run #3: crashed: KASAN: use-after-free Read in get_block
run #4: crashed: KASAN: use-after-free Read in get_block
run #5: crashed: KASAN: out-of-bounds Read in get_block
run #6: crashed: KASAN: use-after-free Read in get_block
run #7: crashed: KASAN: out-of-bounds Read in get_block
run #8: crashed: KASAN: use-after-free Read in get_block
run #9: crashed: KASAN: out-of-bounds Read in get_block
testing release v4.20
testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0
kernel signature: af38c772141f50d16f76e12ad8af83c51f70a836c3ac15aba540abeedf73aa74
run #0: crashed: KASAN: use-after-free Read in get_block
run #1: crashed: KASAN: use-after-free Read in get_block
run #2: crashed: KASAN: out-of-bounds Read in get_block
run #3: crashed: KASAN: out-of-bounds Read in get_block
run #4: crashed: KASAN: use-after-free Read in get_block
run #5: crashed: KASAN: out-of-bounds Read in get_block
run #6: crashed: KASAN: use-after-free Read in get_block
run #7: crashed: KASAN: use-after-free Read in get_block
run #8: crashed: KASAN: use-after-free Read in get_block
run #9: crashed: KASAN: use-after-free Read in get_block
testing release v4.19
testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0
kernel signature: 52634e600dbeebc45e14d2ebd8d756c20b74f5c9b2d4c291fa9c3c383c5f371c
run #0: crashed: KASAN: use-after-free Read in get_block
run #1: crashed: KASAN: use-after-free Read in get_block
run #2: crashed: KASAN: use-after-free Read in get_block
run #3: crashed: KASAN: use-after-free Read in get_block
run #4: crashed: KASAN: use-after-free Read in get_block
run #5: crashed: KASAN: use-after-free Read in get_block
run #6: crashed: KASAN: use-after-free Read in get_block
run #7: crashed: KASAN: use-after-free Read in get_block
run #8: crashed: KASAN: use-after-free Read in get_block
run #9: crashed: KASAN: out-of-bounds Read in get_block
testing release v4.18
testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.1.0
kernel signature: 5bb6ab8171c0c822955d554d7123385544bd82eb9db4b659d60c98aaf744f319
run #0: crashed: KASAN: use-after-free Read in get_block
run #1: crashed: KASAN: use-after-free Read in get_block
run #2: crashed: KASAN: use-after-free Read in get_block
run #3: crashed: KASAN: out-of-bounds Read in get_block
run #4: crashed: KASAN: use-after-free Read in get_block
run #5: crashed: KASAN: use-after-free Read in get_block
run #6: crashed: KASAN: use-after-free Read in get_block
run #7: crashed: KASAN: out-of-bounds Read in get_block
run #8: crashed: KASAN: use-after-free Read in get_block
run #9: crashed: KASAN: use-after-free Read in get_block
testing release v4.17
testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.1.0
kernel signature: c29e2c12557bd4e7154bbc68ef559a916a577a3b80c4311b63e36cfc06d29563
run #0: crashed: KASAN: use-after-free Read in get_block
run #1: crashed: KASAN: use-after-free Read in get_block
run #2: crashed: KASAN: use-after-free Read in get_block
run #3: crashed: KASAN: use-after-free Read in get_block
run #4: crashed: KASAN: use-after-free Read in get_block
run #5: crashed: KASAN: use-after-free Read in get_block
run #6: crashed: KASAN: slab-out-of-bounds Read in get_block
run #7: crashed: KASAN: slab-out-of-bounds Read in get_block
run #8: crashed: KASAN: use-after-free Read in get_block
run #9: crashed: KASAN: out-of-bounds Read in get_block
testing release v4.16
testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0
kernel signature: f895e56e10a5077a1eb83ecab4da510914823cc9bceaefc7776fe90bb9ea309d
run #0: crashed: KASAN: out-of-bounds Read in get_block
run #1: crashed: KASAN: use-after-free Read in get_block
run #2: crashed: KASAN: use-after-free Read in get_block
run #3: crashed: KASAN: use-after-free Read in get_block
run #4: crashed: KASAN: use-after-free Read in get_block
run #5: crashed: KASAN: use-after-free Read in get_block
run #6: crashed: KASAN: use-after-free Read in get_block
run #7: crashed: KASAN: use-after-free Read in get_block
run #8: crashed: KASAN: use-after-free Read in get_block
run #9: crashed: KASAN: use-after-free Read in get_block
testing release v4.15
testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.1.0
kernel signature: af71f61d24d7a9f10b9956127762a6f7721112dbdff5c9cbe55e4b44651f1f88
run #0: crashed: KASAN: use-after-free Read in get_block
run #1: crashed: KASAN: out-of-bounds Read in get_block
run #2: crashed: KASAN: use-after-free Read in get_block
run #3: crashed: KASAN: use-after-free Read in get_block
run #4: crashed: KASAN: out-of-bounds Read in get_block
run #5: crashed: KASAN: use-after-free Read in get_block
run #6: crashed: KASAN: use-after-free Read in get_block
run #7: crashed: KASAN: use-after-free Read in get_block
run #8: crashed: INFO: task hung in path_openat
run #9: crashed: KASAN: use-after-free Read in get_block
testing release v4.14
testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.1.0
kernel signature: 640b13eeb556016951a7b11e56ab2523b89580e94f0af58076e2a8ff56296478
run #0: crashed: KASAN: use-after-free Read in get_block
run #1: crashed: KASAN: slab-out-of-bounds Read in get_block
run #2: crashed: KASAN: slab-out-of-bounds Read in get_block
run #3: crashed: KASAN: slab-out-of-bounds Read in get_block
run #4: crashed: KASAN: use-after-free Read in get_block
run #5: crashed: KASAN: use-after-free Read in get_block
run #6: crashed: KASAN: use-after-free Read in get_block
run #7: crashed: KASAN: use-after-free Read in get_block
run #8: crashed: KASAN: use-after-free Read in get_block
run #9: crashed: KASAN: use-after-free Read in get_block
testing release v4.13
testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.1.0
kernel signature: de35c94d73fb0e651f9d7f7eb48c124c39164b88b231068c20ad554e221a2f70
run #0: crashed: KASAN: slab-out-of-bounds Read in get_block
run #1: crashed: KASAN: use-after-free Read in get_block
run #2: crashed: KASAN: use-after-free Read in get_block
run #3: crashed: KASAN: use-after-free Read in get_block
run #4: crashed: KASAN: use-after-free Read in get_block
run #5: crashed: KASAN: out-of-bounds Read in get_block
run #6: crashed: KASAN: slab-out-of-bounds Read in get_block
run #7: crashed: KASAN: use-after-free Read in get_block
run #8: crashed: KASAN: out-of-bounds Read in get_block
run #9: crashed: KASAN: use-after-free Read in get_block
testing release v4.12
testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.1.0
kernel signature: 40b531fcd39e1c8f8b4d4563dc75b2e9ad97a9716ad42e87e98a647f6afdee92
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: 6462e1d2beadf1afc37b9d2281c0b8c2db6af9fe95fd77afd618a7cb9837b309
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: 59f052964cc7b2f83d842027cfca2b4610ef38c496edf9b6df359caa647306a4
run #0: crashed: KASAN: slab-out-of-bounds Read in V1_minix_get_block
run #1: crashed: KASAN: slab-out-of-bounds Read in V1_minix_get_block
run #2: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #3: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #4: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #5: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #6: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #7: crashed: KASAN: slab-out-of-bounds Read in V1_minix_get_block
run #8: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #9: crashed: KASAN: use-after-free Read in V1_minix_get_block
testing release v4.9
testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0
kernel signature: 34a6189e4f768fa00912c95452e82bb01a8f771ba6146522b6d09ad1ab909fe6
run #0: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #1: crashed: KASAN: out-of-bounds Read in V1_minix_get_block
run #2: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #3: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #4: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #5: crashed: KASAN: out-of-bounds Read in V1_minix_get_block
run #6: crashed: KASAN: out-of-bounds Read in V1_minix_get_block
run #7: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #8: crashed: KASAN: out-of-bounds Read in V1_minix_get_block
run #9: crashed: KASAN: use-after-free Read in V1_minix_get_block
testing release v4.8
testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0
kernel signature: 6121678709b4437c2b7484ef821f8d8a140ebc812e8bb0d5a198357d21a2462d
run #0: crashed: KASAN: slab-out-of-bounds Read in V1_minix_get_block
run #1: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #2: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #3: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #4: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #5: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #6: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #7: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #8: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #9: crashed: KASAN: use-after-free Read in V1_minix_get_block
testing release v4.7
testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0
kernel signature: e799f9276765a313ceb8012d5b1ffcdbada1fdf67130331d2e70762885d57b3c
run #0: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #1: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #2: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #3: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #4: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #5: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #6: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #7: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #8: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #9: crashed: INFO: task hung in path_openat
testing release v4.6
testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0
kernel signature: 9fd131a3c0782569d34d13d40d1ac5b26c7f89831d5ca8072e2341f23fe08a83
all runs: crashed: WARNING in sysfs_warn_dup
revisions tested: 23, total time: 4h15m38.389505212s (build: 2h9m19.560310655s, test: 2h3m50.595435818s)
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
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5878 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: 5878 Comm: syz-executor.2 Not tainted 4.6.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 ffff8800b202efc8 ffffffff82c65932 ffffffff85c81040
 ffff8800b202f0a0 ffffffff85d2bb00 ffffffff8191b86b 0000000000000009
 ffff8800b202f090 ffffffff8160d374 0000000041b58ab3 ffffffff868f058a
Call Trace:
 [<ffffffff82c65932>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff82c65932>] dump_stack+0x136/0x1d4 lib/dump_stack.c:51
 [<ffffffff8160d374>] panic+0x1af/0x348 kernel/panic.c:152
 [<ffffffff81335ecd>] __warn+0x18d/0x1b0 kernel/panic.c:504
 [<ffffffff81335f82>] warn_slowpath_fmt+0x92/0xb0 kernel/panic.c:527
 [<ffffffff8191b86b>] sysfs_warn_dup+0x7b/0xa0 fs/sysfs/dir.c:30
 [<ffffffff8191c0e1>] sysfs_do_create_link_sd.isra.0+0xd1/0xf0 fs/sysfs/symlink.c:51
 [<ffffffff8191c143>] sysfs_do_create_link fs/sysfs/symlink.c:80 [inline]
 [<ffffffff8191c143>] sysfs_create_link+0x43/0xb0 fs/sysfs/symlink.c:92
 [<ffffffff83530157>] device_add_class_symlinks drivers/base/core.c:891 [inline]
 [<ffffffff83530157>] device_add+0x677/0x1350 drivers/base/core.c:1086
 [<ffffffff83531198>] device_create_groups_vargs+0x1c8/0x220 drivers/base/core.c:1709
 [<ffffffff83531298>] device_create_vargs drivers/base/core.c:1749 [inline]
 [<ffffffff83531298>] device_create+0x88/0xa0 drivers/base/core.c:1785
 [<ffffffff838d0584>] macvtap_device_event+0x1c4/0x2a0 drivers/net/macvtap.c:1298
 [<ffffffff81399feb>] notifier_call_chain+0x8b/0x170 kernel/notifier.c:93
 [<ffffffff8139a0f1>] __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 [<ffffffff8139a0f1>] raw_notifier_call_chain+0x11/0x20 kernel/notifier.c:401
 [<ffffffff84920687>] call_netdevice_notifiers_info+0x47/0x80 net/core/dev.c:1643
 [<ffffffff849450d8>] call_netdevice_notifiers net/core/dev.c:1659 [inline]
 [<ffffffff849450d8>] register_netdevice+0x8e8/0xd00 net/core/dev.c:7027
 [<ffffffff838c7cd9>] macvlan_common_newlink+0x8b9/0x1090 drivers/net/macvlan.c:1316
 [<ffffffff838ce94f>] macvtap_newlink+0xbf/0x110 drivers/net/macvtap.c:471
 [<ffffffff84975b8b>] rtnl_newlink+0xd4b/0x1230 net/core/rtnetlink.c:2466
 [<ffffffff84970632>] rtnetlink_rcv_msg+0x222/0x680 net/core/rtnetlink.c:3513
 [<ffffffff84af3c52>] netlink_rcv_skb+0x242/0x350 net/netlink/af_netlink.c:2277
 [<ffffffff84970405>] rtnetlink_rcv+0x25/0x30 net/core/rtnetlink.c:3519
 [<ffffffff84af27ea>] netlink_unicast_kernel net/netlink/af_netlink.c:1214 [inline]
 [<ffffffff84af27ea>] netlink_unicast+0x3da/0x560 net/netlink/af_netlink.c:1240
 [<ffffffff84af341b>] netlink_sendmsg+0x9bb/0xb40 net/netlink/af_netlink.c:1786
 [<ffffffff848cf915>] sock_sendmsg_nosec net/socket.c:612 [inline]
 [<ffffffff848cf915>] sock_sendmsg+0xb5/0xf0 net/socket.c:622
 [<ffffffff848d370a>] SYSC_sendto net/socket.c:1648 [inline]
 [<ffffffff848d370a>] SyS_sendto+0x1ca/0x290 net/socket.c:1616
 [<ffffffff85b70740>] entry_SYSCALL_64_fastpath+0x23/0xc1
Kernel Offset: disabled