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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff88801ff1742a by task syz.0.9473/9370

CPU: 0 UID: 0 PID: 9370 Comm: syz.0.9473 Not tainted 6.16.0-rc6-syzkaller-01646-g56613001dfc9 #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/0x230
 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
 do_softirq+0xec/0x180
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0
 bpf_test_run_xdp_live+0x1868/0x1b10
 bpf_prog_test_run_xdp+0x713/0x1000
 bpf_prog_test_run+0x2c7/0x340
 __sys_bpf+0x4a4/0x860
 __x64_sys_bpf+0x7c/0x90
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f87a138e9a9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f87a2115038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f87a15b5fa0 RCX: 00007f87a138e9a9
RDX: 0000000000000050 RSI: 0000200000000740 RDI: 000000000000000a
RBP: 00007f87a1410d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f87a15b5fa0 R15: 00007ffd0ddcbdf8
 </TASK>

Allocated by task 9308:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 device_add+0xbe/0xb50
 netdev_register_kobject+0x178/0x310
 register_netdevice+0x126c/0x1ae0
 tun_set_iff+0x844/0xef0
 __tun_chr_ioctl+0x788/0x1df0
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 9308:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x62/0x70
 kfree+0x18e/0x440
 kobject_put+0x22b/0x480
 netdev_run_todo+0xd2e/0xea0
 tun_chr_close+0x13c/0x1c0
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x22e0
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88801ff17400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff88801ff17400, ffff88801ff17600)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88801ff17400 pfn:0x1ff14
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88801a441c80 ffffea0000e90b10 ffff88801a4407c8
raw: ffff88801ff17400 000000000010000d 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801a441c80 ffffea0000e90b10 ffff88801a4407c8
head: ffff88801ff17400 000000000010000d 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00007fc501 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 32295, tgid 32293 (syz.1.7000), ts 734279244654, free_ts 726165772666
 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/0x3b0
 ___slab_alloc+0xbfc/0x1480
 __kmalloc_noprof+0x305/0x4f0
 ops_init+0x7b/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
page last free pid 20074 tgid 20074 stack trace:
 __free_frozen_pages+0xc71/0xe70
 vfree+0x25a/0x400
 delayed_vfree_work+0x55/0x80
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

Memory state around the buggy address:
 ffff88801ff17300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801ff17380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88801ff17400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88801ff17480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801ff17500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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