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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff88810af9fc2a by task syz.0.3917/24456

CPU: 1 UID: 0 PID: 24456 Comm: syz.0.3917 Not tainted syzkaller #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:deref_stack_reg+0x1b3/0x230
Code: 39 f0 0f 96 c0 20 c8 3c 01 75 30 4c 89 c7 49 89 f7 e8 11 08 00 00 49 89 c6 48 8b 5c 24 18 48 89 d8 48 c1 e8 03 42 80 3c 38 00 <74> 08 48 89 df e8 b3 2d b0 00 4c 89 33 b0 01 eb 02 31 c0 48 83 c4
RSP: 0018:ffffc900062df1a0 EFLAGS: 00000246
RAX: 1ffff92000c5be61 RBX: ffffc900062df308 RCX: 0000000000000001
RDX: ffffc900062df308 RSI: dffffc0000000000 RDI: ffffc900062df6c8
RBP: 1ffff92000c5be59 R08: ffffc900062df6c8 R09: 0000000000000000
R10: ffffc900062df318 R11: fffff52000c5be65 R12: 1ffff92000c5be5a
R13: 1ffff92000c5be5b R14: 0000000000008000 R15: dffffc0000000000
 unwind_next_frame+0x17c4/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_node_noprof+0x234/0x3d0
 __get_vm_area_node+0x13f/0x300
 __vmalloc_node_range_noprof+0x301/0x12f0
 __vmalloc_node_noprof+0xc2/0x110
 dup_task_struct+0x3e7/0x860
 copy_process+0x54b/0x3c00
 kernel_clone+0x21e/0x840
 __se_sys_clone3+0x256/0x2d0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f428dbc3449
Code: d7 08 00 48 8d 3d 5c d7 08 00 e8 02 29 f6 ff 66 90 b8 ea ff ff ff 48 85 ff 74 2c 48 85 d2 74 27 49 89 c8 b8 b3 01 00 00 0f 05 <48> 85 c0 7c 18 74 01 c3 31 ed 48 83 e4 f0 4c 89 c7 ff d2 48 89 c7
RSP: 002b:00007fffb585abd8 EFLAGS: 00000206 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 00007f428db45850 RCX: 00007f428dbc3449
RDX: 00007f428db45850 RSI: 0000000000000058 RDI: 00007fffb585ac20
RBP: 00007f428e9646c0 R08: 00007f428e9646c0 R09: 00007fffb585ad07
R10: 0000000000000008 R11: 0000000000000206 R12: ffffffffffffffa8
R13: 000000000000004d R14: 00007fffb585ac20 R15: 00007fffb585ad08
 </TASK>

Allocated by task 24418:
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 dst_alloc+0x105/0x170
 ip_route_output_key_hash_rcu+0x14e1/0x23d0
 ip_route_output_key_hash+0x1b9/0x2e0
 ip_route_output_flow+0x2a/0x150
 udp_sendmsg+0x142e/0x2170
 __sock_sendmsg+0x19c/0x270
 ____sys_sendmsg+0x52d/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __sys_sendmmsg+0x227/0x430
 __x64_sys_sendmmsg+0xa0/0xc0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 20066:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kmem_cache_free+0x18f/0x400
 dst_destroy+0x235/0x350
 rcu_core+0xcab/0x1770
 handle_softirqs+0x286/0x870
 do_softirq+0xec/0x180
 __local_bh_enable_ip+0x17d/0x1c0
 batadv_nc_purge_paths+0x318/0x3b0
 batadv_nc_worker+0x328/0x610
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 call_rcu+0x157/0x9c0
 skb_release_head_state+0x71/0x250
 kfree_skb_list_reason+0x21b/0x460
 __dev_queue_xmit+0x21d3/0x3b50
 ip_finish_output2+0xd40/0x1160
 ip_output+0x2a1/0x3c0
 ip_send_skb+0x74/0x100
 udp_send_skb+0xaf1/0x14c0
 udp_sendmsg+0x195a/0x2170
 __sock_sendmsg+0x19c/0x270
 ____sys_sendmsg+0x52d/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __sys_sendmmsg+0x227/0x430
 __x64_sys_sendmmsg+0xa0/0xc0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88810af9fc00
 which belongs to the cache rtable of size 184
The buggy address is located 42 bytes inside of
 freed 184-byte region [ffff88810af9fc00, ffff88810af9fcb8)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10af9f
flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000000 ffff88801da87c80 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000100010 00000000f5000000 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 24418, tgid 24414 (syz.1.3907), ts 342328494815, free_ts 342306036817
 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
 kmem_cache_alloc_noprof+0x283/0x3c0
 dst_alloc+0x105/0x170
 ip_route_output_key_hash_rcu+0x14e1/0x23d0
 ip_route_output_key_hash+0x1b9/0x2e0
 ip_route_output_flow+0x2a/0x150
 udp_sendmsg+0x142e/0x2170
 __sock_sendmsg+0x19c/0x270
 ____sys_sendmsg+0x52d/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __sys_sendmmsg+0x227/0x430
page last free pid 23 tgid 23 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 __tlb_remove_table+0x2d2/0x3b0
 tlb_remove_table_rcu+0x85/0x100
 rcu_core+0xcab/0x1770
 handle_softirqs+0x286/0x870
 run_ksoftirqd+0x9b/0x100
 smpboot_thread_fn+0x542/0xa60
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

Memory state around the buggy address:
 ffff88810af9fb00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88810af9fb80: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc
>ffff88810af9fc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88810af9fc80: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc
 ffff88810af9fd00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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