================================================================== BUG: KASAN: slab-use-after-free in kernfs_test_super+0x122/0x150 fs/kernfs/mount.c:286 Read of size 8 at addr ffff8880231bb688 by task syz-executor.1/26271 CPU: 1 PID: 26271 Comm: syz-executor.1 Not tainted 6.5.0-syzkaller-00453-g727dbda16b83 #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: 0033:0x7f135367cae9 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:00007f13543c00c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f135379bf80 RCX: 00007f135367cae9 RDX: 00000000200000c0 RSI: 0000000020000080 RDI: 0000000000000000 RBP: 00007f13536c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000001000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f135379bf80 R15: 00007f13538bfa48 Allocated by task 26275: 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 26275: 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 do_new_mount_fc fs/namespace.c:3266 [inline] do_new_mount fs/namespace.c:3337 [inline] path_mount+0x1533/0x1ed0 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 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:3368 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:2981 release_sock+0x58/0x1b0 net/core/sock.c:3518 sctp_wait_for_connect+0x1c8/0x5b0 net/sctp/socket.c:9341 sctp_sendmsg_to_asoc+0x1725/0x1a90 net/sctp/socket.c:1884 sctp_sendmsg+0xee4/0x1e80 net/sctp/socket.c:2030 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:830 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg+0xd9/0x180 net/socket.c:748 __sys_sendto+0x255/0x340 net/socket.c:2134 __do_sys_sendto net/socket.c:2146 [inline] __se_sys_sendto net/socket.c:2142 [inline] __x64_sys_sendto+0xe0/0x1b0 net/socket.c:2142 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:3368 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_primitive_SHUTDOWN+0x9f/0xc0 net/sctp/primitive.c:89 sctp_close+0x3ed/0x940 net/sctp/socket.c:1527 inet_release+0x132/0x270 net/ipv4/af_inet.c:427 inet6_release+0x4f/0x70 net/ipv6/af_inet6.c:480 __sock_release+0xcd/0x290 net/socket.c:654 sock_close+0x1c/0x20 net/socket.c:1386 __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 The buggy address belongs to the object at ffff8880231bb680 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 8 bytes inside of freed 64-byte region [ffff8880231bb680, ffff8880231bb6c0) The buggy address belongs to the physical page: page:ffffea00008c6ec0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x231bb flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000200 ffff888012841640 dead000000000100 dead000000000122 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 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 5126, tgid 5122 (syz-executor.1), ts 146017364289, free_ts 145985690574 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 __do_kmalloc_node mm/slab_common.c:984 [inline] __kmalloc+0x4c/0x100 mm/slab_common.c:998 kmalloc include/linux/slab.h:586 [inline] kzalloc include/linux/slab.h:703 [inline] tomoyo_encode2+0x100/0x3d0 security/tomoyo/realpath.c:45 tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x196/0x710 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x243/0x590 security/tomoyo/file.c:723 security_file_ioctl+0x72/0xb0 security/security.c:2622 __do_sys_ioctl fs/ioctl.c:865 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0xbb/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 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 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x18b/0x1d0 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook mm/slab.h:762 [inline] slab_alloc_node mm/slub.c:3470 [inline] kmem_cache_alloc_node+0x185/0x3f0 mm/slub.c:3515 __alloc_skb+0x287/0x330 net/core/skbuff.c:634 alloc_skb include/linux/skbuff.h:1289 [inline] alloc_skb_with_frags+0x9d/0x700 net/core/skbuff.c:6233 sock_alloc_send_pskb+0x7c8/0x950 net/core/sock.c:2793 sock_alloc_send_skb include/net/sock.h:1878 [inline] mld_newpack.isra.0+0x1ee/0x790 net/ipv6/mcast.c:1748 add_grhead+0x295/0x340 net/ipv6/mcast.c:1851 add_grec+0x10bb/0x1680 net/ipv6/mcast.c:1989 mld_send_initial_cr.part.0+0xe2/0x260 net/ipv6/mcast.c:2236 mld_send_initial_cr net/ipv6/mcast.c:2227 [inline] mld_dad_work+0x57/0x2e0 net/ipv6/mcast.c:2262 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600 worker_thread+0x687/0x1110 kernel/workqueue.c:2751 Memory state around the buggy address: ffff8880231bb580: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff8880231bb600: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc >ffff8880231bb680: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8880231bb700: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff8880231bb780: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================