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BUG: KASAN: slab-use-after-free in string+0x216/0x2d0
Read of size 1 at addr ffff8881056fc758 by task udevd/5059

CPU: 0 UID: 0 PID: 5059 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_address_description+0x55/0x1e0
 print_report+0x58/0x70
 kasan_report+0x117/0x150
 string+0x216/0x2d0
 vsnprintf+0x74a/0xef0
 add_uevent_var+0x1ce/0x460
 rc_dev_uevent+0x164/0x1a0
 dev_uevent+0x537/0x870
 uevent_show+0x1a0/0x310
 dev_attr_show+0x58/0xc0
 sysfs_kf_seq_show+0x331/0x490
 seq_read_iter+0x463/0xca0
 vfs_read+0x595/0xa80
 ksys_read+0x150/0x270
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb08d716b6a
Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffdc0ea3e48 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000055959adebbe0 RCX: 00007fb08d716b6a
RDX: 0000000000001000 RSI: 000055959ae19f80 RDI: 000000000000000c
RBP: 000055959adebbe0 R08: 000000000000000c R09: 0000000000000800
R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000003fff R14: 00007ffdc0ea4328 R15: 000000000000000a
 </TASK>

Allocated by task 5692:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x321/0x600
 redrat3_dev_probe+0x477/0x2570
 usb_probe_interface+0x788/0xe50
 really_probe+0x254/0xae0
 __driver_probe_device+0x1e8/0x360
 driver_probe_device+0x4f/0x240
 __device_attach_driver+0x270/0x410
 bus_for_each_drv+0x258/0x2f0
 __device_attach+0x2c4/0x450
 device_initial_probe+0xa1/0xd0
 bus_probe_device+0x12a/0x220
 device_add+0x7d7/0xb80
 usb_set_configuration+0x1ad8/0x2180
 usb_generic_driver_probe+0x8d/0x150
 usb_probe_device+0x1c3/0x3b0
 really_probe+0x254/0xae0
 __driver_probe_device+0x1e8/0x360
 driver_probe_device+0x4f/0x240
 __device_attach_driver+0x270/0x410
 bus_for_each_drv+0x258/0x2f0
 __device_attach+0x2c4/0x450
 device_initial_probe+0xa1/0xd0
 bus_probe_device+0x12a/0x220
 device_add+0x7d7/0xb80
 usb_new_device+0x9aa/0x1690
 hub_event+0x28e8/0x4d30
 process_scheduled_works+0xc3d/0x1630
 worker_thread+0xa47/0xfb0
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30

Freed by task 5692:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x40/0x50
 __kasan_slab_free+0x5c/0x80
 kfree+0x1c5/0x650
 redrat3_dev_probe+0x1bf4/0x2570
 usb_probe_interface+0x788/0xe50
 really_probe+0x254/0xae0
 __driver_probe_device+0x1e8/0x360
 driver_probe_device+0x4f/0x240
 __device_attach_driver+0x270/0x410
 bus_for_each_drv+0x258/0x2f0
 __device_attach+0x2c4/0x450
 device_initial_probe+0xa1/0xd0
 bus_probe_device+0x12a/0x220
 device_add+0x7d7/0xb80
 usb_set_configuration+0x1ad8/0x2180
 usb_generic_driver_probe+0x8d/0x150
 usb_probe_device+0x1c3/0x3b0
 really_probe+0x254/0xae0
 __driver_probe_device+0x1e8/0x360
 driver_probe_device+0x4f/0x240
 __device_attach_driver+0x270/0x410
 bus_for_each_drv+0x258/0x2f0
 __device_attach+0x2c4/0x450
 device_initial_probe+0xa1/0xd0
 bus_probe_device+0x12a/0x220
 device_add+0x7d7/0xb80
 usb_new_device+0x9aa/0x1690
 hub_event+0x28e8/0x4d30
 process_scheduled_works+0xc3d/0x1630
 worker_thread+0xa47/0xfb0
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff8881056fc000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1880 bytes inside of
 freed 2048-byte region [ffff8881056fc000, ffff8881056fc800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1056f8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x17ff00000000040(head|node=0|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 017ff00000000040 ffff888100042000 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 017ff00000000040 ffff888100042000 dead000000000100 dead000000000122
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 017ff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 2886268682
 post_alloc_hook+0x1f9/0x250
 get_page_from_freelist+0x2209/0x2280
 __alloc_frozen_pages_noprof+0x217/0x5a0
 allocate_slab+0x7d/0x620
 refill_objects+0x2d5/0x350
 __pcs_replace_empty_main+0x2c8/0x6c0
 __kmalloc_cache_noprof+0x39b/0x600
 acpi_add_single_object+0xde/0x1b60
 acpi_bus_check_add+0x2b7/0x8a0
 acpi_ns_walk_namespace+0x273/0x700
 acpi_walk_namespace+0x125/0x190
 acpi_bus_scan+0x465/0x4f0
 acpi_scan_init+0x1b1/0x470
 acpi_init+0x130/0x1f0
 do_one_initcall+0x250/0x870
 do_initcall_level+0x10a/0x1a0
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8881056fc600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881056fc680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881056fc700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff8881056fc780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881056fc800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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