================================================================== BUG: KASAN: slab-use-after-free in __raw_spin_lock include/linux/spinlock_api_smp.h:190 [inline] BUG: KASAN: slab-use-after-free in _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:173 Read of size 1 at addr ffff8880516d29d8 by task syz.1.714/7870 CPU: 3 UID: 0 PID: 7870 Comm: syz.1.714 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595 __kasan_check_byte+0x36/0x50 mm/kasan/common.c:574 kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire kernel/locking/lockdep.c:5860 [inline] lock_acquire+0x132/0x370 kernel/locking/lockdep.c:5843 __raw_spin_lock include/linux/spinlock_api_smp.h:190 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:173 spin_lock include/linux/spinlock.h:347 [inline] ref_tracker_debugfs_show+0xf6/0x1c0 lib/ref_tracker.c:394 seq_read_iter+0x32f/0x1270 fs/seq_file.c:231 seq_read+0x344/0x4d0 fs/seq_file.c:163 full_proxy_read+0x135/0x1a0 fs/debugfs/file.c:378 vfs_read+0x1e4/0xb40 fs/read_write.c:572 ksys_read+0x12a/0x250 fs/read_write.c:716 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x13a/0x8b0 arch/x86/entry/syscall_32.c:291 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf700efec Code: Unable to access opcode bytes at 0xf700efc2. RSP: 002b:00000000f53fd50c EFLAGS: 00000292 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000080000580 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 7558: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4584 [inline] slab_alloc_node mm/slub.c:4917 [inline] kmem_cache_alloc_noprof+0x26b/0x6a0 mm/slub.c:4931 net_alloc net/core/net_namespace.c:490 [inline] copy_net_ns+0xe8/0x7c0 net/core/net_namespace.c:563 create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:132 unshare_nsproxy_namespaces+0xf2/0x220 kernel/nsproxy.c:234 ksys_unshare+0x4a2/0xa70 kernel/fork.c:3298 __do_sys_unshare kernel/fork.c:3362 [inline] __se_sys_unshare kernel/fork.c:3360 [inline] __ia32_sys_unshare+0x30/0x40 kernel/fork.c:3360 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x13a/0x8b0 arch/x86/entry/syscall_32.c:291 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 5806: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2677 [inline] slab_free mm/slub.c:6377 [inline] kmem_cache_free+0x127/0x6b0 mm/slub.c:6504 net_complete_free net/core/net_namespace.c:526 [inline] cleanup_net+0x51a/0x920 net/core/net_namespace.c:711 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff8880516d2740 which belongs to the cache net_namespace of size 9792 The buggy address is located 664 bytes inside of freed 9792-byte region [ffff8880516d2740, ffff8880516d4d80) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880516d2740 pfn:0x516d0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff8880516d75c1 flags: 0x4fff00000000240(workingset|head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000240 ffff88801de89180 ffffea0001e60410 ffffea0001ae6210 raw: ffff8880516d2740 0000000800030001 00000000f5000000 ffff8880516d75c1 head: 04fff00000000240 ffff88801de89180 ffffea0001e60410 ffffea0001ae6210 head: ffff8880516d2740 0000000800030001 00000000f5000000 ffff8880516d75c1 head: 04fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7558, tgid 7556 (syz.0.613), ts 81195049624, free_ts 81191928751 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0xf46/0x3500 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3266 [inline] allocate_slab mm/slub.c:3380 [inline] new_slab+0xa2/0x660 mm/slub.c:3426 refill_objects+0xe3/0x410 mm/slub.c:7310 refill_sheaf mm/slub.c:2804 [inline] __pcs_replace_empty_main+0x372/0x680 mm/slub.c:4675 alloc_from_pcs mm/slub.c:4773 [inline] slab_alloc_node mm/slub.c:4905 [inline] kmem_cache_alloc_noprof+0x46e/0x6a0 mm/slub.c:4931 net_alloc net/core/net_namespace.c:490 [inline] copy_net_ns+0xe8/0x7c0 net/core/net_namespace.c:563 create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:132 unshare_nsproxy_namespaces+0xf2/0x220 kernel/nsproxy.c:234 ksys_unshare+0x4a2/0xa70 kernel/fork.c:3298 __do_sys_unshare kernel/fork.c:3362 [inline] __se_sys_unshare kernel/fork.c:3360 [inline] __ia32_sys_unshare+0x30/0x40 kernel/fork.c:3360 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x13a/0x8b0 arch/x86/entry/syscall_32.c:291 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316 entry_SYSENTER_compat_after_hwframe+0x84/0x8e page last free pid 41 tgid 41 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] free_pages_prepare+0x586/0xd80 mm/page_alloc.c:1451 __free_contig_range_common+0x14f/0x250 mm/page_alloc.c:6897 __free_contig_range mm/page_alloc.c:6942 [inline] free_pages_bulk+0x12a/0x200 mm/page_alloc.c:5257 vm_area_free_pages+0xad/0x2b0 mm/vmalloc.c:3461 vfree mm/vmalloc.c:3510 [inline] vfree+0x108/0x730 mm/vmalloc.c:3484 delayed_vfree_work+0x56/0x80 mm/vmalloc.c:3414 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff8880516d2880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880516d2900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880516d2980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880516d2a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880516d2a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================