bisecting cause commit starting from 189522da8b3a796d56d802e067d591d2ffff7f40
building syzkaller on 2e44d63e401ead7d7928c95a30d243b2de1a243b
testing commit 189522da8b3a796d56d802e067d591d2ffff7f40 with gcc (GCC) 8.1.0
kernel signature: 583b0248378825d9efa500d76e2e65672c3ba6a5c661412eae2716633d6f4229
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: 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: KASAN: out-of-bounds 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: 3df0ce90b743fd480cea194a6c2df38a86c461fa483449ac135589c4f7c34ed4
all runs: crashed: KASAN: use-after-free Read in get_block
testing release v5.5
testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.1.0
kernel signature: e9b3a48cd8e7aed5630540644ca8544c9701b646a70b22d42a06707f8ec6b900
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: 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: OK
testing release v5.4
testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0
kernel signature: 0b5dd06251a3baf378df4d56df6fc2d4be41443d04f824fb5c89fc58353a7000
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: use-after-free Read in get_block
run #9: crashed: KASAN: use-after-free Read in get_block
testing release v5.3
testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0
kernel signature: c8632af56f5160dc3c64de1480b035d3424a628734c68905a002277824c018ae
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: 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: out-of-bounds 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 v5.2
testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0
kernel signature: db6c25fd64bb7117651d130b49addd1c7be01cbe12ccd620d6428fb724513407
all runs: crashed: KASAN: use-after-free Read in get_block
testing release v5.1
testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0
kernel signature: 33e3322a707fbf035767b215327ca69492d9f16853ee243fbeb5562afbbe3004
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: 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 v5.0
testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0
kernel signature: a338eaa96b7bdb308c8a2ccebd76626b1bcbae18814319126d30a7210eec2b49
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: 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 v4.20
testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0
kernel signature: a7f1fe728c8483800d8f2c09f34343826aac69ec81b439e1b5490fea9a53fad6
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: 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: out-of-bounds 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 v4.19
testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0
kernel signature: f45c19196b5459a210ca4edca7c2ab0ce62730b2b3343d680135e1db4c4e5ff7
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: use-after-free Read in get_block
run #9: crashed: KASAN: use-after-free Read in get_block
testing release v4.18
testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.1.0
kernel signature: 4189806ba182a7e565c1dcbbf99cb04a4e9bbf114872b403e92a96fbcc513fe5
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: out-of-bounds 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: ae078101864161cbaae857851868d5cd8e0268e2699e643c0bd779d1a2ab180c
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: use-after-free Read in get_block
testing release v4.16
testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0
kernel signature: c02b6a9d3dbdadd95ebc6bcb3bf0fed3079f457290dc84d8c76f7ff86e12ad67
run #0: crashed: KASAN: out-of-bounds 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: 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: slab-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 v4.15
testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.1.0
kernel signature: 1ed2430606e7d172def03363be67aec5fd34d58365c5ebaf250321585c941c2b
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: 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: INFO: task hung in path_openat
testing release v4.14
testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.1.0
kernel signature: 8db865149f4db69acba1e9c66d977fa0263614219c2681c0e7281422d01b9a95
run #0: crashed: KASAN: slab-out-of-bounds Read in get_block
run #1: crashed: KASAN: slab-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: 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 v4.13
testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.1.0
kernel signature: e16e5ba717633a18ed47bb26f487072bbbd2dc4bb14eaa040e3fd1b195775db0
run #0: crashed: KASAN: slab-out-of-bounds 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: slab-out-of-bounds Read in get_block
run #5: crashed: KASAN: slab-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: use-after-free 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: 1b860e84995fc5406eacb0363c606e3d899a615601c4605071a02094791e76f4
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: 5fa06390f4976a84d9d63e7dd2f49f22b030763645a403b422877d2f81cf9319
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: 133a76aaaa79527b3cd75603c849fa5e248d39a59b151ebd25ee4a9ca23166da
run #0: crashed: KASAN: use-after-free Read in V1_minix_get_block
run #1: crashed: KASAN: slab-out-of-bounds Read in V1_minix_get_block
run #2: crashed: KASAN: slab-out-of-bounds Read in V1_minix_get_block
run #3: crashed: KASAN: slab-out-of-bounds 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: out-of-bounds Read in V1_minix_get_block
testing release v4.9
testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0
kernel signature: d108085d8248eb03c3fa9a3cec571e05dfb94a710b074de931ce38424d9bdb13
run #0: crashed: KASAN: slab-out-of-bounds 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: out-of-bounds Read in V1_minix_get_block
run #5: crashed: KASAN: out-of-bounds Read in V1_minix_get_block
run #6: crashed: KASAN: slab-out-of-bounds Read in V1_minix_get_block
run #7: crashed: KASAN: 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 v4.8
testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0
kernel signature: 96b60c5c0ad195a861570768b47054b86377f32d45e08e039965973565ab22fe
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: slab-out-of-bounds Read in V1_minix_get_block
run #4: crashed: KASAN: slab-out-of-bounds Read in V1_minix_get_block
run #5: crashed: KASAN: slab-out-of-bounds Read in V1_minix_get_block
run #6: crashed: KASAN: slab-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: 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: 0ab31fdfe50a7ed16aacad96433d0b2975e95839ab4fee4c6f56a7fafa3c0101
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: out-of-bounds Read in V1_minix_get_block
run #9: crashed: KASAN: use-after-free Read in V1_minix_get_block
testing release v4.6
testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0
kernel signature: d99c2c3933880e3fe6f2f2c0251aa22b009ff006cb21e42255a58e8264fe0ffd
all runs: crashed: WARNING in sysfs_warn_dup
revisions tested: 23, total time: 4h8m15.566991191s (build: 2h6m1.945249709s, test: 1h59m39.128619625s)
the crash already happened on the oldest tested release
commit msg: Linux 4.6
crash: WARNING in sysfs_warn_dup
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5887 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: 5887 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
 0000000000000000 ffff88012920efc8 ffffffff82c65932 ffffffff85c81040
 ffff88012920f0a0 ffffffff85d2bb00 ffffffff8191b86b 0000000000000009
 ffff88012920f090 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