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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff8880306eb82a by task syz-executor/5845

CPU: 1 UID: 0 PID: 5845 Comm: syz-executor Not tainted 6.16.0-syzkaller-12063-g37816488247d-dirty #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:__might_resched+0x8c/0x610
Code: 40 48 c1 eb 03 48 b8 f1 f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 09 f2 f2 f2 00 66 42 c7 44 2b 0d f3 f3 42 c6 44 2b 0f f3 <e8> 2f 1c e7 09 85 c0 74 46 48 c7 c7 40 9f 13 8e be ff ff ff ff e8
RSP: 0018:ffffc9000301fd00 EFLAGS: 00000a02
RAX: f2f2f200f1f1f1f1 RBX: 1ffff92000603fa8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000075 RDI: ffffffff8d9f810b
RBP: ffffc9000301fe08 R08: 00000000ffffffff R09: 0000000000000000
R10: ffff88812039d500 R11: ffffffff81ac3890 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff8d9f810b R15: 0000000000000000
 __might_fault+0x77/0x130
 strncpy_from_user+0x31/0x290
 getname_flags+0xf3/0x540
 __x64_sys_unlink+0x3a/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f959ab8e197
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 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:00007ffdf89cdba8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f959ab8e197
RDX: 00007ffdf89cdbd0 RSI: 00007ffdf89cdc60 RDI: 00007ffdf89cdc60
RBP: 00007ffdf89cdc60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffdf89cecf0
R13: 00007f959ac11c05 R14: 000000000005edb1 R15: 00007ffdf89ced30
 </TASK>

Allocated by task 5911:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 batadv_forw_packet_alloc+0x1e9/0x390
 batadv_iv_ogm_queue_add+0x85f/0xd30
 batadv_iv_ogm_schedule+0xb48/0xf00
 batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

Freed by task 13:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 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
 insert_work+0x3d/0x330
 __queue_work+0xbaf/0xfb0
 call_timer_fn+0x17e/0x5f0
 __run_timer_base+0x646/0x860
 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
 asm_sysvec_apic_timer_interrupt+0x1a/0x20

The buggy address belongs to the object at ffff8880306eb800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff8880306eb800, ffff8880306eba00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880306e9400 pfn:0x306e8
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 ffffea0000a03410 ffffea0000811f10
raw: ffff8880306e9400 000000000010000e 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801a441c80 ffffea0000a03410 ffffea0000811f10
head: ffff8880306e9400 000000000010000e 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000c1ba01 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 5845, tgid 5845 (syz-executor), ts 65897578686, free_ts 0
 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_noprof+0x305/0x4f0
 fib6_info_alloc+0x30/0xf0
 ip6_route_info_create+0x142/0x860
 ip6_route_add+0x49/0x1b0
 add_v4_addrs+0x8b3/0xbd0
 addrconf_init_auto_addrs+0x6da/0xa30
 addrconf_notify+0xacc/0x1010
 notifier_call_chain+0x1b6/0x3e0
 __dev_notify_flags+0x18d/0x2e0
 netif_change_flags+0xe8/0x1a0
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8880306eb700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880306eb780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880306eb800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff8880306eb880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880306eb900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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