bisecting cause commit starting from 3af409ca278d4a8d50e91f9f7c4c33b175645cf3
building syzkaller on 3e5ed8b45e7a561d6344a4d3d7bf3bfb8f24a7b3
testing commit 3af409ca278d4a8d50e91f9f7c4c33b175645cf3 with gcc (GCC) 10.2.1 20210217
kernel signature: 20c455d8a58ab564b3d2acb25c1b998aa7a1929f4ff4fed292c78b6985cb6102
run #0: crashed: WARNING: refcount bug in nbd_config_put
run #1: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #2: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #3: crashed: KASAN: use-after-free Write in nbd_release
run #4: crashed: WARNING: refcount bug in nbd_config_put
run #5: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #6: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #7: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #8: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #9: crashed: WARNING: refcount bug in nbd_config_put
run #10: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #11: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #12: crashed: KASAN: use-after-free Read in nbd_release
run #13: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #14: crashed: KASAN: use-after-free Read in nbd_release
run #15: crashed: KASAN: use-after-free Read in nbd_release
run #16: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #17: crashed: KASAN: use-after-free Read in nbd_release
run #18: crashed: KASAN: use-after-free Read in nbd_release
run #19: crashed: KASAN: use-after-free Read in nbd_release
testing release v5.10
testing commit 2c85ebc57b3e1817b6ce1a6b703928e113a90442 with gcc (GCC) 10.2.1 20210217
kernel signature: 5f141e4ae086409e6817ce9d751cdfb7d552f8adb2d1ef3d6d87c18b4d1705fb
run #0: crashed: KASAN: use-after-free Read in nbd_release
run #1: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #2: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #3: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #4: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #5: crashed: WARNING: refcount bug in nbd_config_put
run #6: crashed: KASAN: use-after-free Read in nbd_release
run #7: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #8: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #9: crashed: WARNING: refcount bug in nbd_config_put
testing release v5.9
testing commit bbf5c979011a099af5dc76498918ed7df445635b with gcc (GCC) 10.2.1 20210217
kernel signature: e2e25caecac98c53dcc4037f7b7493ea80c7d8d6d1cace370152d06c198de71a
run #0: crashed: KASAN: use-after-free Write in nbd_release
run #1: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #2: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #3: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #4: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #5: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #6: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #7: crashed: WARNING: refcount bug in nbd_config_put
run #8: crashed: KASAN: use-after-free Read in nbd_genl_connect
run #9: crashed: KASAN: use-after-free Read in nbd_genl_connect
testing release v5.8
testing commit bcf876870b95592b52519ed4aafcf9d95999bc9c with gcc (GCC) 8.4.1 20210217
kernel signature: ebe503c532ccb3d1993aaef10f6bc2c8917bfe36c5635f4b67af9fe784be5408
run #0: crashed: KASAN: use-after-free Read in nbd_put
run #1: crashed: WARNING: refcount bug in nbd_put
run #2: crashed: WARNING: refcount bug in nbd_put
run #3: crashed: KASAN: use-after-free Read in nbd_put
run #4: crashed: KASAN: use-after-free Write in nbd_put
run #5: crashed: KASAN: use-after-free Read in nbd_put
run #6: crashed: KASAN: use-after-free Read in nbd_put
run #7: crashed: WARNING: refcount bug in nbd_put
run #8: crashed: WARNING: refcount bug in nbd_put
run #9: crashed: KASAN: use-after-free Read in nbd_put
testing release v5.7
testing commit 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 with gcc (GCC) 8.4.1 20210217
kernel signature: 165c15419a41e1841f9e545c62b09764973faab07fd5dccba1741f2663589c9d
run #0: crashed: WARNING: refcount bug in nbd_put
run #1: crashed: KASAN: use-after-free Write in nbd_put
run #2: crashed: KASAN: use-after-free Read in nbd_put
run #3: crashed: KASAN: use-after-free Write in nbd_put
run #4: crashed: KASAN: use-after-free Write in nbd_put
run #5: crashed: KASAN: use-after-free Read in nbd_put
run #6: crashed: KASAN: use-after-free Read in nbd_put
run #7: crashed: KASAN: use-after-free Read in nbd_put
run #8: crashed: KASAN: use-after-free Read in nbd_put
run #9: crashed: KASAN: use-after-free Read in nbd_put
testing release v5.6
testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.4.1 20210217
kernel signature: 607b4d24bcd728fbbe58a31c361ba4de45c143eca8bdba2156ec671aa076d031
run #0: crashed: KASAN: use-after-free Read in nbd_put
run #1: crashed: WARNING: refcount bug in nbd_put
run #2: crashed: KASAN: use-after-free Read in nbd_put
run #3: crashed: KASAN: use-after-free Write in nbd_put
run #4: crashed: KASAN: use-after-free Write in nbd_put
run #5: crashed: KASAN: use-after-free Read in nbd_put
run #6: crashed: KASAN: use-after-free Read in nbd_put
run #7: crashed: KASAN: use-after-free Read in nbd_put
run #8: crashed: KASAN: use-after-free Read in nbd_put
run #9: crashed: KASAN: use-after-free Read in nbd_put
testing release v5.5
testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.4.1 20210217
kernel signature: e3ea87a5cdcdc7a07a9f946f111325bc11fa802083fed683a999bd100237afe1
all runs: crashed: KASAN: use-after-free Read in nbd_put
testing release v5.4
testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.4.1 20210217
kernel signature: f9022fc8d1dc65754e8233407bdf81707e0e8782cdd07acb2c7e239e71fb8aa7
run #0: crashed: KASAN: use-after-free Read in nbd_put
run #1: crashed: KASAN: use-after-free Read in nbd_put
run #2: crashed: KASAN: use-after-free Write in ex_handler_refcount
run #3: crashed: KASAN: use-after-free Write in ex_handler_refcount
run #4: crashed: WARNING: refcount bug in nbd_put
run #5: crashed: KASAN: use-after-free Read in nbd_put
run #6: crashed: KASAN: use-after-free Read in nbd_put
run #7: crashed: KASAN: use-after-free Read in nbd_put
run #8: crashed: KASAN: use-after-free Read in nbd_put
run #9: crashed: KASAN: use-after-free Write in ex_handler_refcount
testing release v5.3
testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.4.1 20210217
kernel signature: 9afac535adde0aac0bcb75468d72a58c44fc9c4c934ca98816eb18219faa432f
all runs: boot failed: BUG: spinlock bad magic in nf_connlabels_get
testing release v5.2
testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.4.1 20210217
kernel signature: 95e3a7b0c5596d76463e8444a88f95ba032a1d51c5f84f3c540b7cdf423cdc2b
all runs: boot failed: can't ssh into the instance
testing release v5.1
testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.4.1 20210217
kernel signature: 47a06d801aff7f156d428698f81afec1369d9e079c1c4a17567fef5c07d0993c
all runs: boot failed: can't ssh into the instance
testing release v5.0
testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.4.1 20210217
kernel signature: 578a73029469ae44402e2122661a7e001f2ba2c2a5423c2fb05026dfdc39875d
all runs: boot failed: can't ssh into the instance
testing release v4.20
testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.4.1 20210217
kernel signature: a5b90fa9d65b9c10ec5a5c72a0285ab326d114d7f7b423072bd8fea115f06437
all runs: boot failed: can't ssh into the instance
testing release v4.19
testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.4.1 20210217
kernel signature: e5a9975a55243aba6ffedb9df61cbabf8143a42cf632e710469f980aab1791c9
all runs: boot failed: can't ssh into the instance
testing release v4.18
testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.4.1 20210217
kernel signature: 028a53e145201fe41a600950ce42783f91bc0eaa8718f63d81dfdbcbeb487e71
all runs: boot failed: can't ssh into the instance
testing release v4.17
testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.4.1 20210217
failed to run ["make" "-j" "64" "ARCH=x86_64" "CC=/syzkaller/shared/bisect_bin/gcc-8.1.0/bin/gcc" "bzImage"]: exit status 2
testing release v4.16
testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.4.1 20210217
orc_dump.c:106:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
orc_dump.c:111:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
elf.c:135:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:140:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
testing release v4.15
testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.4.1 20210217
orc_dump.c:106:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
orc_dump.c:111:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
pager.c:36:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
elf.c:135:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:140:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
testing release v4.14
testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.4.1 20210217
orc_dump.c:105:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
orc_dump.c:110:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
pager.c:36:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
elf.c:134:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:139:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
testing release v4.13
testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.4.1 20210217
pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
elf.c:144:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:149:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
testing release v4.12
testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.4.1 20210217
pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
elf.c:141:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:146:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
testing release v4.11
testing commit a351e9b9fc24e982ec2f0e76379a49826036da12 with gcc (GCC) 7.5.0
elf.c:141:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:146:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
testing release v4.10
testing commit c470abd4fde40ea6a0846a2beab642a578c0b8cd with gcc (GCC) 5.5.0
tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes]
elf.c:129:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:134:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
testing release v4.9
testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0
tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes]
elf.c:129:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:134:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
testing release v4.8
testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0
tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes]
elf.c:129:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:134:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
pager.c:33:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
testing release v4.7
testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0
tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes]
pager.c:33:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
elf.c:122:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:127:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
testing release v4.6
testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0
tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes]
pager.c:33:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
revisions tested: 15, total time: 3h45m48.571592094s (build: 2h3m55.045875317s, test: 1h37m59.012458927s)
the crash already happened on the oldest tested release
commit msg: Linux 5.4
crash: KASAN: use-after-free Write in ex_handler_refcount
==================================================================
BUG: KASAN: use-after-free in ex_handler_refcount+0x135/0x170 arch/x86/mm/extable.c:57
Write of size 4 at addr ffff8880b4795908 by task systemd-udevd/11114

CPU: 1 PID: 11114 Comm: systemd-udevd Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x96/0xe0 lib/dump_stack.c:118
 print_address_description.constprop.4.cold.6+0x9/0x373 mm/kasan/report.c:374
 __kasan_report.cold.7+0x7a/0x95 mm/kasan/report.c:506
 kasan_report+0xe/0x20 mm/kasan/common.c:634
 ex_handler_refcount+0x135/0x170 arch/x86/mm/extable.c:57
 fixup_exception+0x8b/0xc6 arch/x86/mm/extable.c:227
 do_trap_no_signal arch/x86/kernel/traps.c:207 [inline]
 do_trap+0x6a/0x250 arch/x86/kernel/traps.c:251
 do_invalid_op+0x31/0x40 arch/x86/kernel/traps.c:291
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
RIP: 0010:csum_partial_copy_generic+0x2e2c/0x9370
Code: 4c 24 08 0f 0b 48 8d 8f 28 01 00 00 0f 0b 48 8d 4f 08 0f 0b 48 8d 8b 08 02 00 00 0f 0b 48 8d 0b 0f 0b 48 8d 0b 0f 0b 48 8d 0b <0f> 0b 49 8d 8f 50 13 00 00 0f 0b 48 8d 4d 00 0f 0b 48 8d 0f 0f 0b
RSP: 0018:ffff8880b4167d00 EFLAGS: 00010296
RAX: 0000000000000000 RBX: ffff8880b4795908 RCX: ffff8880b4795908
RDX: ffffed101682cf76 RSI: 0000000000000004 RDI: ffffffff8e23b220
RBP: 0000000000000000 R08: fffffbfff15ccc52 R09: fffffbfff15ccc52
R10: ffff8880b4167d00 R11: ffffffff8ae6628b R12: ffffffff8ae66280
R13: ffff888096aa0018 R14: ffff888096aa0000 R15: dffffc0000000000
 nbd_put+0x1a/0x1c0 drivers/block/nbd.c:248
 __blkdev_put+0x487/0x5e0 fs/block_dev.c:1867
 blkdev_close+0x84/0xc0 fs/block_dev.c:1936
 __fput+0x256/0x790 fs/file_table.c:280
 task_work_run+0xd3/0x180 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x15d/0x200 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x42f/0x4e0 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f4b11c4f270
Code: 73 01 c3 48 8b 0d 38 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 59 c1 20 00 00 75 10 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ee fb ff ff 48 89 04 24
RSP: 002b:00007ffe0a942c38 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f4b11c4f270
RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 00007f4b12b09710 R08: 0000000000000045 R09: 0000000000000018
R10: 0000555e95bb1928 R11: 0000000000000246 R12: 0000000000000000
R13: 0000555e95baeac0 R14: 0000000000000003 R15: 000000000000000e

Allocated by task 11091:
 save_stack+0x19/0x80 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc mm/kasan/common.c:510 [inline]
 __kasan_kmalloc.constprop.11+0xc1/0xd0 mm/kasan/common.c:483
 kmalloc include/linux/slab.h:556 [inline]
 kzalloc include/linux/slab.h:690 [inline]
 nbd_dev_add+0x47/0x820 drivers/block/nbd.c:1654
 nbd_genl_connect+0x4c5/0x122d drivers/block/nbd.c:1826
 genl_family_rcv_msg+0x5ff/0xf40 net/netlink/genetlink.c:629
 genl_rcv_msg+0xb3/0x160 net/netlink/genetlink.c:654
 netlink_rcv_skb+0x119/0x340 net/netlink/af_netlink.c:2477
 genl_rcv+0x1f/0x30 net/netlink/genetlink.c:665
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x3fc/0x5c0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x71e/0xb70 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0xac/0xf0 net/socket.c:657
 ___sys_sendmsg+0x653/0x950 net/socket.c:2311
 __sys_sendmsg+0xce/0x170 net/socket.c:2356
 do_syscall_64+0x8e/0x4e0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 11095:
 save_stack+0x19/0x80 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 kasan_set_free_info mm/kasan/common.c:332 [inline]
 __kasan_slab_free+0x124/0x170 mm/kasan/common.c:471
 slab_free_hook mm/slub.c:1424 [inline]
 slab_free_freelist_hook+0x53/0x140 mm/slub.c:1457
 slab_free mm/slub.c:3004 [inline]
 kfree+0xd6/0x3b0 mm/slub.c:3956
 nbd_dev_remove drivers/block/nbd.c:243 [inline]
 nbd_put drivers/block/nbd.c:251 [inline]
 nbd_put+0x16f/0x1c0 drivers/block/nbd.c:246
 nbd_genl_connect+0xdc3/0x122d drivers/block/nbd.c:1968
 genl_family_rcv_msg+0x5ff/0xf40 net/netlink/genetlink.c:629
 genl_rcv_msg+0xb3/0x160 net/netlink/genetlink.c:654
 netlink_rcv_skb+0x119/0x340 net/netlink/af_netlink.c:2477
 genl_rcv+0x1f/0x30 net/netlink/genetlink.c:665
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x3fc/0x5c0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x71e/0xb70 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0xac/0xf0 net/socket.c:657
 ___sys_sendmsg+0x653/0x950 net/socket.c:2311
 __sys_sendmsg+0xce/0x170 net/socket.c:2356
 do_syscall_64+0x8e/0x4e0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880b4795800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 264 bytes inside of
 512-byte region [ffff8880b4795800, ffff8880b4795a00)
The buggy address belongs to the page:
page:ffffea0002d1e500 refcount:1 mapcount:0 mapping:ffff8880b5802500 index:0x0 compound_mapcount: 0
raw: 00fff00000010200 0000000000000000 0000000100000001 ffff8880b5802500
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880b4795800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880b4795880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880b4795900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff8880b4795980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880b4795a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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