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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff88802f72cc2a by task syz.9.9819/32045

CPU: 0 UID: 0 PID: 32045 Comm: syz.9.9819 Not tainted 6.16.0-syzkaller-11895-gcca7a0aae895-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:
 <TASK>
 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+0x57/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0033:0x7f04b8850c4b
Code: cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 47 0f b6 0c 08 <45> 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01 49 89 47 10 83
RSP: 002b:00007f04b97e94a0 EFLAGS: 00000206
RAX: 00000000009caf83 RBX: 00007f04b97e9540 RCX: 00000000000000d8
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f04b97e95e0
RBP: 0000000000000102 R08: 00007f04ae600000 R09: 0000000000000000
R10: 0000000000000000 R11: 00007f04b97e9550 R12: 0000000000000001
R13: 00007f04b8a2d980 R14: 0000000000000000 R15: 00007f04b97e95e0
 </TASK>

Allocated by task 12:
 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 5707:
 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 ffff88802f72cc00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff88802f72cc00, ffff88802f72ce00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88802f72cc00 pfn:0x2f72c
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 ffffea00009fa210 ffffea0000fd7310
raw: ffff88802f72cc00 000000000010000f 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801a441c80 ffffea00009fa210 ffffea0000fd7310
head: ffff88802f72cc00 000000000010000f 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000bdcb01 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 13, tgid 13 (kworker/u8:1), ts 750567534041, free_ts 746985242509
 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
 __ipv6_dev_mc_inc+0x44f/0xa50
 addrconf_dad_work+0x3d0/0x14b0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
page last free pid 17893 tgid 17893 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 vfree+0x25a/0x400
 kcov_close+0x28/0x50
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x2300
 do_group_exit+0x21c/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x21f7/0x2200
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88802f72cb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802f72cb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802f72cc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88802f72cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802f72cd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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vkms_vblank_simulate: vblank timer overrun
