================================================================== BUG: KASAN: slab-use-after-free in kernfs_test_super+0x122/0x150 fs/kernfs/mount.c:286 Read of size 8 at addr ffff888049234608 by task syz-executor.1/7653 CPU: 0 PID: 7653 Comm: syz-executor.1 Not tainted 6.5.0-syzkaller-03967-gbd6c11bc43c4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 kernfs_test_super+0x122/0x150 fs/kernfs/mount.c:286 sget_fc+0x582/0x9b0 fs/super.c:778 kernfs_get_tree+0x198/0x990 fs/kernfs/mount.c:337 sysfs_get_tree+0x41/0x140 fs/sysfs/mount.c:31 vfs_get_tree+0x8c/0x370 fs/super.c:1711 do_new_mount fs/namespace.c:3335 [inline] path_mount+0x1492/0x1ed0 fs/namespace.c:3662 do_mount fs/namespace.c:3675 [inline] __do_sys_mount fs/namespace.c:3884 [inline] __se_sys_mount fs/namespace.c:3861 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:3861 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fda1567cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fda1638f0c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fda1579bf80 RCX: 00007fda1567cae9 RDX: 0000000020000040 RSI: 00000000200001c0 RDI: 0000000000000000 RBP: 00007fda156c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fda1579bf80 R15: 00007ffdf556f248 Allocated by task 7646: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:582 [inline] kzalloc include/linux/slab.h:703 [inline] kernfs_get_tree+0x78/0x990 fs/kernfs/mount.c:328 sysfs_get_tree+0x41/0x140 fs/sysfs/mount.c:31 vfs_get_tree+0x8c/0x370 fs/super.c:1711 do_new_mount fs/namespace.c:3335 [inline] path_mount+0x1492/0x1ed0 fs/namespace.c:3662 do_mount fs/namespace.c:3675 [inline] __do_sys_mount fs/namespace.c:3884 [inline] __se_sys_mount fs/namespace.c:3861 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:3861 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 17201: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15e/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1792 [inline] slab_free_freelist_hook+0x10b/0x1e0 mm/slub.c:1818 slab_free mm/slub.c:3801 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3814 sysfs_kill_sb+0x21/0x30 fs/sysfs/mount.c:86 deactivate_locked_super+0xa0/0x2d0 fs/super.c:454 deactivate_super+0xde/0x100 fs/super.c:504 cleanup_mnt+0x222/0x3d0 fs/namespace.c:1254 task_work_run+0x14d/0x240 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x210/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492 kvfree_call_rcu+0x70/0xbe0 kernel/rcu/tree.c:3372 sctp_bind_addr_clean+0x133/0x1f0 net/sctp/bind_addr.c:131 sctp_association_free+0x292/0x7d0 net/sctp/associola.c:356 sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:944 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1330 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline] sctp_do_sm+0x2636/0x5c40 net/sctp/sm_sideeffect.c:1169 sctp_assoc_bh_rcv+0x392/0x6f0 net/sctp/associola.c:1051 sctp_inq_push+0x1d5/0x270 net/sctp/inqueue.c:80 sctp_backlog_rcv+0x169/0x590 net/sctp/input.c:331 sk_backlog_rcv include/net/sock.h:1115 [inline] __release_sock+0x132/0x3a0 net/core/sock.c:2982 release_sock+0x58/0x1b0 net/core/sock.c:3519 sctp_close+0x447/0x940 net/sctp/socket.c:1535 inet_release+0x132/0x270 net/ipv4/af_inet.c:433 inet6_release+0x4f/0x70 net/ipv6/af_inet6.c:484 __sock_release+0xae/0x260 net/socket.c:657 sock_close+0x1c/0x20 net/socket.c:1399 __fput+0x3f7/0xa70 fs/file_table.c:384 __fput_sync+0x47/0x50 fs/file_table.c:465 __do_sys_close fs/open.c:1572 [inline] __se_sys_close fs/open.c:1557 [inline] __x64_sys_close+0x87/0xf0 fs/open.c:1557 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Second to last potentially related work creation: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492 kvfree_call_rcu+0x70/0xbe0 kernel/rcu/tree.c:3372 ip6addrlbl_net_exit+0x10a/0x1b0 net/ipv6/addrlabel.c:347 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:170 setup_net+0x64d/0xa40 net/core/net_namespace.c:362 copy_net_ns+0x2fa/0x670 net/core/net_namespace.c:491 create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:228 ksys_unshare+0x3da/0x930 kernel/fork.c:3446 __do_sys_unshare kernel/fork.c:3517 [inline] __se_sys_unshare kernel/fork.c:3515 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3515 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888049234600 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 8 bytes inside of freed 64-byte region [ffff888049234600, ffff888049234640) The buggy address belongs to the physical page: page:ffffea0001248d00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888049234800 pfn:0x49234 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000200 ffff888012841640 ffffea0000c77c10 ffffea0000a92090 raw: ffff888049234800 000000000020001f 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 0x112820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 18350, tgid 18348 (syz-executor.1), ts 838722198854, free_ts 838707152127 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d2/0x350 mm/page_alloc.c:1570 prep_new_page mm/page_alloc.c:1577 [inline] get_page_from_freelist+0x10a9/0x31e0 mm/page_alloc.c:3221 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4477 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2298 alloc_slab_page mm/slub.c:1862 [inline] allocate_slab+0x24e/0x380 mm/slub.c:2009 new_slab mm/slub.c:2062 [inline] ___slab_alloc+0x8bc/0x1570 mm/slub.c:3215 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3314 __slab_alloc_node mm/slub.c:3367 [inline] slab_alloc_node mm/slub.c:3460 [inline] __kmem_cache_alloc_node+0x137/0x350 mm/slub.c:3509 kmalloc_trace+0x25/0xe0 mm/slab_common.c:1076 kmalloc include/linux/slab.h:582 [inline] ip_setup_cork+0x6d4/0x970 net/ipv4/ip_output.c:1295 ip_append_data net/ipv4/ip_output.c:1354 [inline] ip_append_data+0x160/0x190 net/ipv4/ip_output.c:1340 icmp_push_reply+0xab/0x450 net/ipv4/icmp.c:370 __icmp_send+0xccc/0x17e0 net/ipv4/icmp.c:770 icmp_send include/net/icmp.h:43 [inline] ip_protocol_deliver_rcu+0x3ee/0x480 net/ipv4/ip_input.c:216 ip_local_deliver_finish+0x2e6/0x520 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:304 [inline] NF_HOOK include/linux/netfilter.h:298 [inline] ip_local_deliver+0x1be/0x540 net/ipv4/ip_input.c:254 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1161 [inline] free_unref_page_prepare+0x508/0xb90 mm/page_alloc.c:2348 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2443 vfree+0x181/0x7a0 mm/vmalloc.c:2842 delayed_vfree_work+0x56/0x70 mm/vmalloc.c:2763 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600 worker_thread+0x687/0x1110 kernel/workqueue.c:2751 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Memory state around the buggy address: ffff888049234500: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888049234580: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc >ffff888049234600: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff888049234680: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888049234700: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================