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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff88803cfdd42a by task syz.3.2706/17425

CPU: 0 UID: 0 PID: 17425 Comm: syz.3.2706 Not tainted 6.16.0-syzkaller-06620-gae633388cae3 #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:mutex_spin_on_owner+0x27b/0x360
Code: be 08 00 00 00 e8 a5 e1 85 00 42 80 7c 35 00 00 74 08 4c 89 e7 e8 25 df 85 00 49 f7 04 24 01 00 00 00 0f 85 8c 00 00 00 f3 90 <4c> 89 e7 be 08 00 00 00 e8 78 e1 85 00 42 80 7c 35 00 00 0f 84 90
RSP: 0018:ffffc90006e77988 EFLAGS: 00000246
RAX: 1ffff11020f7eac8 RBX: ffffffff8f508ff0 RCX: ffffffff819cf498
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001
RBP: 1ffffffff1ea11f4 R08: ffffffff8f508fa7 R09: 1ffffffff1ea11f4
R10: dffffc0000000000 R11: fffffbfff1ea11f5 R12: ffffffff8f508fa0
R13: ffffffff8f508ff0 R14: dffffc0000000000 R15: ffff88801fae9cc0
 __mutex_lock+0x311/0x1340
 br_ioctl_stub+0x199/0xc80
 sock_ioctl+0x4d8/0x790
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd685b8ebe9
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:00007fd686a10038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd685db5fa0 RCX: 00007fd685b8ebe9
RDX: 0000200000000280 RSI: 00000000000089a0 RDI: 0000000000000003
RBP: 00007fd685c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd685db6038 R14: 00007fd685db5fa0 R15: 00007ffe25518478
 </TASK>

Allocated by task 17302:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 device_add+0xbe/0xb50
 add_one_compat_dev+0x3af/0x5c0
 rdma_dev_init_net+0x1dd/0x270
 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 13:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x62/0x70
 kfree+0x18e/0x440
 kobject_put+0x22b/0x480
 rdma_dev_exit_net+0x1e8/0x340
 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 ffff88803cfdd400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff88803cfdd400, ffff88803cfdd600)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3cfdc
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801a441c80 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801a441c80 0000000000000000 dead000000000001
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000f3f701 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 9200, tgid 9199 (syz.1.699), ts 124960199597, free_ts 115139229756
 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_cache_noprof+0x296/0x3d0
 rxrpc_alloc_peer+0x7d/0x330
 rxrpc_service_prealloc_one+0x1f4/0xe20
 afs_charge_preallocation+0x394/0x4e0
 afs_open_socket+0x302/0x3a0
 afs_net_init+0x67d/0x880
 ops_init+0x35c/0x5c0
 setup_net+0x10c/0x320
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
page last free pid 8690 tgid 8689 stack trace:
 __free_frozen_pages+0xc71/0xe70
 __put_partials+0x161/0x1c0
 put_cpu_partial+0x17c/0x250
 __slab_free+0x2f7/0x400
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 __kmalloc_cache_noprof+0x1be/0x3d0
 __ipv6_dev_mc_inc+0x44f/0xa50
 ipv6_add_dev+0xe63/0x1370
 addrconf_notify+0x794/0x1010
 notifier_call_chain+0x1b6/0x3e0
 register_netdevice+0x1608/0x1ae0
 ppp_dev_configure+0x8a4/0xb10
 ppp_ioctl+0x6a5/0x19a0
 __se_sys_ioctl+0xfc/0x170

Memory state around the buggy address:
 ffff88803cfdd300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88803cfdd380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88803cfdd400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88803cfdd480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88803cfdd500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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