==================================================================
BUG: KASAN: slab-use-after-free in snapshot_ctr+0x586/0x1350 drivers/md/dm-snap.c:1288
Read of size 8 at addr ffff888106b01f18 by task syz.0.5/323

CPU: 0 UID: 0 PID: 323 Comm: syz.0.5 Not tainted syzkaller #0 f4dc25654f8255e5780388d900d0b326847aed68
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
 print_address_description+0x71/0x210 mm/kasan/report.c:377
 print_report+0x4a/0x70 mm/kasan/report.c:481
 kasan_report+0x162/0x1a0 mm/kasan/report.c:594
 __asan_report_load8_noabort+0x18/0x20 mm/kasan/report_generic.c:381
 snapshot_ctr+0x586/0x1350 drivers/md/dm-snap.c:1288
 dm_table_add_target+0x59f/0xcb0 drivers/md/dm-table.c:760
 populate_table drivers/md/dm-ioctl.c:1494 [inline]
 table_load+0x2eb/0x7d0 drivers/md/dm-ioctl.c:1536
 ctl_ioctl drivers/md/dm-ioctl.c:2104 [inline]
 dm_ctl_ioctl+0x8f3/0xde0 drivers/md/dm-ioctl.c:2126
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0x123/0x1b0 fs/ioctl.c:892
 __x64_sys_ioctl+0x7f/0xa0 fs/ioctl.c:892
 x64_sys_call+0x1878/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7ff0c379f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff0c46da028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff0c3a25fa0 RCX: 00007ff0c379f559
RDX: 0000200000000140 RSI: 00000000c138fd09 RDI: 0000000000000003
RBP: 00007ff0c3836b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff0c3a26038 R14: 00007ff0c3a25fa0 R15: 00007fffb796ac18
 </TASK>

Allocated by task 323:
 kasan_save_stack mm/kasan/common.c:49 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
 kasan_save_alloc_info+0x3a/0x50 mm/kasan/generic.c:565
 poison_kmalloc_redzone mm/kasan/common.c:379 [inline]
 __kasan_kmalloc+0x96/0xb0 mm/kasan/common.c:396
 kasan_kmalloc include/linux/kasan.h:261 [inline]
 __kmalloc_cache_node_noprof+0x225/0x430 mm/slub.c:4438
 kmalloc_node_noprof include/linux/slab.h:1004 [inline]
 open_table_device drivers/md/dm.c:758 [inline]
 dm_get_table_device+0x1e3/0x6c0 drivers/md/dm.c:837
 dm_get_device+0x32b/0x7f0 drivers/md/dm-table.c:394
 snapshot_ctr+0x292/0x1350 drivers/md/dm-snap.c:1273
 dm_table_add_target+0x59f/0xcb0 drivers/md/dm-table.c:760
 populate_table drivers/md/dm-ioctl.c:1494 [inline]
 table_load+0x2eb/0x7d0 drivers/md/dm-ioctl.c:1536
 ctl_ioctl drivers/md/dm-ioctl.c:2104 [inline]
 dm_ctl_ioctl+0x8f3/0xde0 drivers/md/dm-ioctl.c:2126
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0x123/0x1b0 fs/ioctl.c:892
 __x64_sys_ioctl+0x7f/0xa0 fs/ioctl.c:892
 x64_sys_call+0x1878/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Freed by task 323:
 kasan_save_stack mm/kasan/common.c:49 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
 kasan_save_free_info+0x44/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:249 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:266
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2445 [inline]
 slab_free mm/slub.c:4714 [inline]
 kfree+0x158/0x440 mm/slub.c:4875
 close_table_device drivers/md/dm.c:814 [inline]
 dm_put_table_device+0x298/0x2e0 drivers/md/dm.c:857
 upgrade_mode drivers/md/dm-table.c:328 [inline]
 dm_get_device+0x571/0x7f0 drivers/md/dm-table.c:405
 snapshot_ctr+0x435/0x1350 drivers/md/dm-snap.c:1283
 dm_table_add_target+0x59f/0xcb0 drivers/md/dm-table.c:760
 populate_table drivers/md/dm-ioctl.c:1494 [inline]
 table_load+0x2eb/0x7d0 drivers/md/dm-ioctl.c:1536
 ctl_ioctl drivers/md/dm-ioctl.c:2104 [inline]
 dm_ctl_ioctl+0x8f3/0xde0 drivers/md/dm-ioctl.c:2126
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0x123/0x1b0 fs/ioctl.c:892
 __x64_sys_ioctl+0x7f/0xa0 fs/ioctl.c:892
 x64_sys_call+0x1878/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

The buggy address belongs to the object at ffff888106b01f00
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 24 bytes inside of
 freed 96-byte region [ffff888106b01f00, ffff888106b01f60)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x106b01
flags: 0x4000000000000000(zone=1)
page_type: f5(slab)
raw: 4000000000000000 ffff888100041280 ffffea00041dcbc0 dead000000000004
raw: 0000000000000000 0000000080200020 00000001f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 4494668359, free_ts 0
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook+0x37d/0x3b0 mm/page_alloc.c:1864
 prep_new_page+0x2d/0x180 mm/page_alloc.c:1872
 get_page_from_freelist+0x4aea/0x4ba0 mm/page_alloc.c:3949
 __alloc_pages_noprof+0x35a/0x7e0 mm/page_alloc.c:5316
 alloc_slab_page+0x6b/0x1e0 mm/slub.c:-1
 allocate_slab+0x69/0x430 mm/slub.c:2687
 new_slab mm/slub.c:2741 [inline]
 ___slab_alloc+0x591/0x8c0 mm/slub.c:3934
 __slab_alloc mm/slub.c:4025 [inline]
 __slab_alloc_node mm/slub.c:4078 [inline]
 slab_alloc_node mm/slub.c:4239 [inline]
 __kmalloc_cache_noprof+0x2cd/0x470 mm/slub.c:4421
 kmalloc_noprof include/linux/slab.h:882 [inline]
 kzalloc_noprof include/linux/slab.h:1117 [inline]
 call_usermodehelper_setup+0x97/0x300 kernel/umh.c:363
 kobject_uevent_env+0x65f/0x7e0 lib/kobject_uevent.c:628
 kobject_uevent+0x21/0x40 lib/kobject_uevent.c:656
 device_add+0x599/0xbf0 drivers/base/core.c:3673
 nvmem_register+0xecf/0x1450 drivers/nvmem/core.c:1047
 devm_nvmem_register+0x1e/0x80 drivers/nvmem/core.c:1132
 devm_rtc_nvmem_register+0xc1/0x120 drivers/rtc/nvmem.c:25
 cmos_do_probe+0xcaf/0x10e0 drivers/rtc/rtc-cmos.c:1117
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888106b01e00: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff888106b01e80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
>ffff888106b01f00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                            ^
 ffff888106b01f80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
 ffff888106b02000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
device-mapper: table: 252:0: device 1:1 not in table devices list
device-mapper: table: 252:0: snapshot: COW device cannot be the same as origin device (-EINVAL)
device-mapper: ioctl: error adding target to table
device-mapper: table: 252:0: dm_table_destroy: dm_put_device call missing for 1:1