================================================================== BUG: KASAN: slab-use-after-free in kernfs_test_super+0x122/0x150 fs/kernfs/mount.c:295 Read of size 8 at addr ffff88805d36ef88 by task syz-executor.3/20359 CPU: 1 PID: 20359 Comm: syz-executor.3 Not tainted 6.5.0-next-20230829-syzkaller #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:295 sget_fc+0x582/0x9b0 fs/super.c:778 kernfs_get_tree+0x198/0x9a0 fs/kernfs/mount.c:346 sysfs_get_tree+0x41/0x140 fs/sysfs/mount.c:31 vfs_get_tree+0x8c/0x370 fs/super.c:1713 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: 0033:0x7fc3af07cae9 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:00007fc3afd140c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fc3af19bf80 RCX: 00007fc3af07cae9 RDX: 00000000200000c0 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 00007fc3af0c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fc3af19bf80 R15: 00007ffd45d96908 Allocated by task 20357: 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:599 [inline] kzalloc include/linux/slab.h:720 [inline] kernfs_get_tree+0x78/0x9a0 fs/kernfs/mount.c:337 sysfs_get_tree+0x41/0x140 fs/sysfs/mount.c:31 vfs_get_tree+0x8c/0x370 fs/super.c:1713 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 20357: 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+0x15b/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3822 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_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:433 inet6_release+0x4f/0x70 net/ipv6/af_inet6.c:484 __sock_release+0xae/0x260 net/socket.c:659 sock_close+0x1c/0x20 net/socket.c:1401 __fput+0x3f7/0xa70 fs/file_table.c:384 task_work_run+0x14d/0x240 kernel/task_work.c:179 get_signal+0x106f/0x27b0 kernel/signal.c:2668 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/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 The buggy address belongs to the object at ffff88805d36ef80 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 8 bytes inside of freed 64-byte region [ffff88805d36ef80, ffff88805d36efc0) The buggy address belongs to the physical page: page:ffffea000174db80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5d36e flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888012c41640 ffffea0000706680 dead000000000004 raw: 0000000000000000 0000000000200020 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 5084, tgid 5084 (syz-executor.4), ts 1147096632543, free_ts 1146874488059 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1530 prep_new_page mm/page_alloc.c:1537 [inline] get_page_from_freelist+0xf17/0x2e50 mm/page_alloc.c:3200 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4456 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2298 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab+0x251/0x380 mm/slub.c:2017 new_slab mm/slub.c:2070 [inline] ___slab_alloc+0x8be/0x1570 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x137/0x350 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1022 [inline] __kmalloc+0x4f/0x100 mm/slab_common.c:1036 kmalloc include/linux/slab.h:603 [inline] kzalloc include/linux/slab.h:720 [inline] ext4_htree_store_dirent+0x92/0x690 fs/ext4/dir.c:474 htree_dirblock_to_tree+0x585/0xd10 fs/ext4/namei.c:1138 ext4_htree_fill_tree+0x395/0xc80 fs/ext4/namei.c:1217 ext4_dx_readdir fs/ext4/dir.c:597 [inline] ext4_readdir+0x2016/0x3720 fs/ext4/dir.c:142 iterate_dir+0x1e5/0x5f0 fs/readdir.c:106 __do_sys_getdents64 fs/readdir.c:405 [inline] __se_sys_getdents64 fs/readdir.c:390 [inline] __x64_sys_getdents64+0x14f/0x2e0 fs/readdir.c:390 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:1130 [inline] free_unref_page_prepare+0x476/0xa40 mm/page_alloc.c:2342 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2435 kasan_depopulate_vmalloc_pte+0x63/0x80 mm/kasan/shadow.c:427 apply_to_pte_range mm/memory.c:2589 [inline] apply_to_pmd_range mm/memory.c:2633 [inline] apply_to_pud_range mm/memory.c:2669 [inline] apply_to_p4d_range mm/memory.c:2705 [inline] __apply_to_page_range+0x5ed/0xdb0 mm/memory.c:2739 kasan_release_vmalloc+0xa8/0xc0 mm/kasan/shadow.c:544 __purge_vmap_area_lazy+0x8b9/0x2160 mm/vmalloc.c:1770 drain_vmap_area_work+0x54/0xd0 mm/vmalloc.c:1804 process_one_work+0x887/0x15d0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8bb/0x1290 kernel/workqueue.c:2784 kthread+0x33a/0x430 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Memory state around the buggy address: ffff88805d36ee80: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ffff88805d36ef00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff88805d36ef80: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff88805d36f000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805d36f080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================