================================================================== BUG: KASAN: slab-use-after-free in snapshot_ctr+0x5cc/0x1340 drivers/md/dm-snap.c:1288 Read of size 8 at addr ffff888031a39298 by task syz.2.2259/14496 CPU: 0 PID: 14496 Comm: syz.2.2259 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xa8/0x210 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 snapshot_ctr+0x5cc/0x1340 drivers/md/dm-snap.c:1288 dm_table_add_target+0x575/0xbc0 drivers/md/dm-table.c:732 populate_table drivers/md/dm-ioctl.c:1502 [inline] table_load+0x2eb/0x7e0 drivers/md/dm-ioctl.c:1544 ctl_ioctl drivers/md/dm-ioctl.c:2115 [inline] dm_ctl_ioctl+0x975/0xd00 drivers/md/dm-ioctl.c:2137 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc3de59f559 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:00007fc3df3e3028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc3de825fa0 RCX: 00007fc3de59f559 RDX: 0000200000002d80 RSI: 00000000c138fd09 RDI: 0000000000000003 RBP: 00007fc3de636b20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc3de826038 R14: 00007fc3de825fa0 R15: 00007ffdec051248 Allocated by task 14496: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384 kmalloc_node include/linux/slab.h:616 [inline] open_table_device drivers/md/dm.c:731 [inline] dm_get_table_device+0x248/0x670 drivers/md/dm.c:800 dm_get_device+0x4b9/0x9e0 drivers/md/dm-table.c:378 snapshot_ctr+0x2b3/0x1340 drivers/md/dm-snap.c:1273 dm_table_add_target+0x575/0xbc0 drivers/md/dm-table.c:732 populate_table drivers/md/dm-ioctl.c:1502 [inline] table_load+0x2eb/0x7e0 drivers/md/dm-ioctl.c:1544 ctl_ioctl drivers/md/dm-ioctl.c:2115 [inline] dm_ctl_ioctl+0x975/0xd00 drivers/md/dm-ioctl.c:2137 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 14496: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1833 [inline] slab_free_freelist_hook+0x154/0x240 mm/slub.c:1859 slab_free mm/slub.c:3853 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3866 close_table_device drivers/md/dm.c:777 [inline] dm_put_table_device+0x20e/0x240 drivers/md/dm.c:820 upgrade_mode drivers/md/dm-table.c:327 [inline] dm_get_device+0x7ca/0x9e0 drivers/md/dm-table.c:389 snapshot_ctr+0x472/0x1340 drivers/md/dm-snap.c:1283 dm_table_add_target+0x575/0xbc0 drivers/md/dm-table.c:732 populate_table drivers/md/dm-ioctl.c:1502 [inline] table_load+0x2eb/0x7e0 drivers/md/dm-ioctl.c:1544 ctl_ioctl drivers/md/dm-ioctl.c:2115 [inline] dm_ctl_ioctl+0x975/0xd00 drivers/md/dm-ioctl.c:2137 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3452 hash_ipport4_add+0x1429/0x20d0 net/netfilter/ipset/ip_set_hash_gen.h:997 hash_ipport4_uadt+0xa67/0xdd0 net/netfilter/ipset/ip_set_hash_ipport.c:199 call_ad+0x185/0xb30 net/netfilter/ipset/ip_set_core.c:1764 ip_set_ad+0x81a/0x9c0 net/netfilter/ipset/ip_set_core.c:1854 nfnetlink_rcv_msg+0xcaf/0x1290 net/netfilter/nfnetlink.c:302 netlink_rcv_skb+0x235/0x4c0 net/netlink/af_netlink.c:2550 nfnetlink_rcv+0x2c9/0x2490 net/netfilter/nfnetlink.c:659 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x7b1/0x930 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1899 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x61b/0x980 net/socket.c:2595 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2649 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2687 [inline] __se_sys_sendmsg+0x1d0/0x2c0 net/socket.c:2685 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Second to last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3452 sctp_bind_addr_clean net/sctp/bind_addr.c:131 [inline] sctp_bind_addr_free+0x12f/0x170 net/sctp/bind_addr.c:140 sctp_association_free+0x2b6/0x7f0 net/sctp/associola.c:357 sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:951 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1341 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1205 [inline] sctp_do_sm+0x3fe2/0x5b70 net/sctp/sm_sideeffect.c:1176 sctp_assoc_bh_rcv+0x3f2/0x630 net/sctp/associola.c:1062 sctp_backlog_rcv+0x15c/0x360 net/sctp/input.c:331 sk_backlog_rcv include/net/sock.h:1146 [inline] __release_sock+0x1ea/0x460 net/core/sock.c:3042 release_sock+0x5f/0x1c0 net/core/sock.c:3581 sctp_sendmsg+0x1b46/0x27b0 net/sctp/socket.c:2043 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x4a9/0x6b0 net/socket.c:2201 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xde/0xf0 net/socket.c:2209 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888031a39280 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 24 bytes inside of freed 64-byte region [ffff888031a39280, ffff888031a392c0) The buggy address belongs to the physical page: page:ffffea0000c68e40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x31a39 flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888018c41640 ffffea0001748840 dead000000000004 raw: 0000000000000000 0000000080200020 00000001ffffffff 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 0x12c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY), pid 5155, tgid 5155 (udevd), ts 45576143819, free_ts 45565138640 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582 prep_new_page mm/page_alloc.c:1589 [inline] get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501 alloc_slab_page+0x5d/0x180 mm/slub.c:1903 allocate_slab mm/slub.c:2050 [inline] new_slab+0x87/0x2d0 mm/slub.c:2103 ___slab_alloc+0xc5c/0x12f0 mm/slub.c:3275 __slab_alloc mm/slub.c:3361 [inline] __slab_alloc_node mm/slub.c:3414 [inline] slab_alloc_node mm/slub.c:3508 [inline] __kmem_cache_alloc_node+0x122/0x260 mm/slub.c:3557 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0xa7/0x240 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:721 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x2ad/0x570 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x57c/0x5c0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x282/0x560 security/tomoyo/file.c:822 security_inode_getattr+0xd3/0x120 security/security.c:2190 vfs_getattr fs/stat.c:173 [inline] vfs_fstat fs/stat.c:198 [inline] __do_sys_newfstat fs/stat.c:473 [inline] __se_sys_newfstat fs/stat.c:470 [inline] __x64_sys_newfstat+0x12c/0x250 fs/stat.c:470 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1182 [inline] free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2459 discard_slab mm/slub.c:2149 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2689 put_cpu_partial+0x17c/0x250 mm/slub.c:2765 __slab_free+0x319/0x400 mm/slub.c:3723 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6a/0x4d0 mm/slab.h:770 slab_alloc_node mm/slub.c:3518 [inline] slab_alloc mm/slub.c:3526 [inline] __kmem_cache_alloc_lru mm/slub.c:3533 [inline] kmem_cache_alloc+0x17e/0x2d0 mm/slub.c:3542 getname_flags+0xbb/0x500 fs/namei.c:145 user_path_at_empty+0x2c/0x60 fs/namei.c:2971 do_readlinkat+0xdd/0x490 fs/stat.c:494 __do_sys_readlink fs/stat.c:527 [inline] __se_sys_readlink fs/stat.c:524 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:524 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff888031a39180: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff888031a39200: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc >ffff888031a39280: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff888031a39300: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff888031a39380: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ==================================================================