==================================================================
BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff88811277782a by task syz-executor/13586

CPU: 0 UID: 0 PID: 13586 Comm: syz-executor Not tainted 6.16.0-syzkaller-12063-g37816488247d #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <IRQ>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 rose_timer_expiry+0x471/0x4b0
 call_timer_fn+0x17e/0x5f0
 __run_timer_base+0x61a/0x860
 run_timer_softirq+0xb7/0x180
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lock_acquire+0x58/0x360
Code: 8b 05 2c 95 02 11 48 89 44 24 58 0f 1f 44 00 00 65 8b 05 2f 95 02 11 83 f8 08 0f 83 b8 01 00 00 89 c0 48 0f a3 05 18 ec 05 0e <73> 16 e8 61 02 09 00 84 c0 75 0d f6 05 d7 d4 ef 0d 01 0f 84 d7 01
RSP: 0000:ffffc9000a457880 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e139fa0
RBP: ffffffff822e5b0a R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff94000895131 R12: 0000000000000002
R13: ffffffff8e139fa0 R14: 0000000000000000 R15: 0000000000000000
 pfn_valid+0xd6/0x490
 page_table_check_set+0x25/0x730
 set_pte_range+0x6a5/0x700
 filemap_map_pages+0xf32/0x1740
 __handle_mm_fault+0x34ac/0x5440
 handle_mm_fault+0x40a/0x8e0
 do_user_addr_fault+0xa81/0x1390
 exc_page_fault+0x76/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7fac8fb185b0
Code: c7 44 24 20 c0 ff ff ff 48 c7 44 24 18 3f 00 00 00 48 c7 44 24 10 40 00 00 00 48 c7 44 24 08 00 00 00 00 e9 ad fd ff ff 66 90 <48> c7 c0 a8 ff ff ff 64 48 03 04 25 00 00 00 00 c3 66 2e 0f 1f 84
RSP: 002b:00007ffff2671158 EFLAGS: 00010286
RAX: ffffffffffffffff RBX: 00007ffff2671160 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 00007ffff2671160 RDI: 000055557b823808
RBP: 00007ffff267159c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000038e
R13: 00000000000927c0 R14: 000000000003a8fb R15: 00007ffff26715f0
 </TASK>

Allocated by task 13468:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 seg6_net_init+0x53/0x160
 ops_init+0x35c/0x5c0
 setup_net+0x10c/0x320
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5866:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 ops_undo_list+0x49a/0x990
 cleanup_net+0x4c5/0x800
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff888112777800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff888112777800, ffff888112777a00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x112774
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801a441c80 ffffea000463d300 dead000000000002
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801a441c80 ffffea000463d300 dead000000000002
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea000449dd01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5296, tgid 5296 (udevd), ts 56753487660, free_ts 56748856939
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x8a/0x370
 ___slab_alloc+0xbeb/0x1410
 __kmalloc_cache_noprof+0x296/0x3d0
 kernfs_fop_open+0x397/0xca0
 do_dentry_open+0x953/0x13f0
 vfs_open+0x3b/0x340
 path_openat+0x2ee5/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5850 tgid 5850 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 stack_depot_save_flags+0x436/0x860
 kasan_save_track+0x4f/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x27a/0x4f0
 memcg_list_lru_alloc+0x261/0x7e0
 __memcg_slab_post_alloc_hook+0x13c/0x7f0
 kmem_cache_alloc_lru_noprof+0x2c7/0x3d0
 alloc_inode+0xb8/0x1b0
 iget_locked+0xf0/0x570
 kernfs_get_inode+0x4f/0x780
 kernfs_iop_lookup+0x1f6/0x320
 __lookup_slow+0x297/0x3d0
 lookup_slow+0x53/0x70
 link_path_walk+0x935/0xea0
 path_openat+0x28c/0x3830

Memory state around the buggy address:
 ffff888112777700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888112777780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888112777800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888112777880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888112777900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
