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BUG: KASAN: slab-out-of-bounds in suffix_kstrtoint.constprop.0+0x214/0x250 fs/xfs/xfs_super.c:1083
Read of size 1 at addr ffff8880a3f2ba7f by task syz-executor.2/10674

CPU: 0 PID: 10674 Comm: syz-executor.2 Not tainted 5.5.0-next-20200206-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+0x197/0x210 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x32 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:641
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 suffix_kstrtoint.constprop.0+0x214/0x250 fs/xfs/xfs_super.c:1083
 xfs_fc_parse_param+0x133/0xcd0 fs/xfs/xfs_super.c:1143
 vfs_parse_fs_param+0x2b4/0x610 fs/fs_context.c:147
 vfs_parse_fs_string+0x10a/0x170 fs/fs_context.c:191
 generic_parse_monolithic+0x181/0x200 fs/fs_context.c:231
 parse_monolithic_mount_data+0x69/0x90 fs/fs_context.c:679
 do_new_mount fs/namespace.c:2818 [inline]
 do_mount+0x1310/0x1b50 fs/namespace.c:3107
 __do_sys_mount fs/namespace.c:3316 [inline]
 __se_sys_mount fs/namespace.c:3293 [inline]
 __x64_sys_mount+0x192/0x230 fs/namespace.c:3293
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45ddea
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 4d 8c fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 2a 8c fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007fc24cb6fa68 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fc24cb706d4 RCX: 000000000045ddea
RDX: 00007fc24cb6fae0 RSI: 00000000200001c0 RDI: 00007fc24cb6fb00
RBP: 000000000075bf20 R08: 00007fc24cb6fb40 R09: 00007fc24cb6fae0
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000ffffffff
R13: 0000000000000bb5 R14: 00000000004cc92a R15: 000000000075bf2c

Allocated by task 1:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:515 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:488
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc_track_caller+0x15f/0x760 mm/slab.c:3671
 kstrdup+0x3a/0x70 mm/util.c:60
 kstrdup_const+0x66/0x80 mm/util.c:82
 __kernfs_new_node+0xb1/0x6e0 fs/kernfs/dir.c:623
 kernfs_new_node+0x96/0x120 fs/kernfs/dir.c:689
 kernfs_create_dir_ns+0x52/0x160 fs/kernfs/dir.c:1026
 sysfs_create_dir_ns+0x131/0x2a0 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:89 [inline]
 kobject_add_internal+0x2d8/0x9a0 lib/kobject.c:255
 kobject_add_varg lib/kobject.c:390 [inline]
 kobject_init_and_add+0x101/0x160 lib/kobject.c:473
 bus_add_driver+0x1e8/0x5d0 drivers/base/bus.c:615
 driver_register+0x1c9/0x330 drivers/base/driver.c:171
 acpi_bus_register_driver+0x106/0x160 drivers/acpi/bus.c:858
 acpi_ac_init+0x116/0x138 drivers/acpi/ac.c:456
 do_one_initcall+0x120/0x820 init/main.c:1123
 do_initcall_level init/main.c:1196 [inline]
 do_initcalls init/main.c:1212 [inline]
 do_basic_setup init/main.c:1232 [inline]
 kernel_init_freeable+0x522/0x5d0 init/main.c:1416
 kernel_init+0x12/0x1bf init/main.c:1323
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8880a3f2ba40
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 31 bytes to the right of
 32-byte region [ffff8880a3f2ba40, ffff8880a3f2ba60)
The buggy address belongs to the page:
page:ffffea00028fcac0 refcount:1 mapcount:0 mapping:ffff8880aa4001c0 index:0xffff8880a3f2bfc1
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002a0e948 ffffea00028af108 ffff8880aa4001c0
raw: ffff8880a3f2bfc1 ffff8880a3f2b000 000000010000003d 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a3f2b900: fb fb fb fb fc fc fc fc 07 fc fc fc fc fc fc fc
 ffff8880a3f2b980: 00 04 fc fc fc fc fc fc 07 fc fc fc fc fc fc fc
>ffff8880a3f2ba00: fb fb fb fb fc fc fc fc 03 fc fc fc fc fc fc fc
                                                                ^
 ffff8880a3f2ba80: 01 fc fc fc fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff8880a3f2bb00: 00 fc fc fc fc fc fc fc 00 fc fc fc fc fc fc fc
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