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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff88810decac2a by task syz-executor/5816

CPU: 0 UID: 0 PID: 5816 Comm: syz-executor Not tainted 6.16.0-syzkaller-06588-g759dfc7d04ba-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:__sanitizer_cov_trace_const_cmp4+0x11/0x90
Code: 09 cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 14 25 08 00 9a 92 <65> 8b 0d 28 4b da 10 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75
RSP: 0018:ffffc9000415f328 EFLAGS: 00000246
RAX: ffffffff822de142 RBX: ffff88801ac80000 RCX: 008aac7c1dd2b800
RDX: ffff888111bad640 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff822dfced
R10: dffffc0000000000 R11: fffff940000dbe51 R12: 000000000001b7ca
R13: dffffc0000000000 R14: ffff88805fffa470 R15: 0000000000001000
 page_ext_lookup+0xf2/0x180
 page_table_check_set+0x27e/0x730
 copy_pmd_range+0x4262/0x7000
 copy_page_range+0xc46/0x1270
 dup_mmap+0xf57/0x1ac0
 copy_mm+0x13c/0x4b0
 copy_process+0x1706/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc06f3853d3
Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffc89918218 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc06f3853d3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055555e2e37d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 0000000000065029 R15: 00007ffc899183b0
 </TASK>

Allocated by task 27351:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 alloc_bprm+0x7d/0x5b0
 kernel_execve+0x9b/0x9f0
 call_usermodehelper_exec_async+0x210/0x360
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

Freed by task 27351:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x62/0x70
 kfree+0x18e/0x440
 kernel_execve+0x3c7/0x9f0
 call_usermodehelper_exec_async+0x210/0x360
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff88810decac00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff88810decac00, ffff88810decae00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88810dec9800 pfn:0x10dec8
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000240(workingset|head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000240 ffff88801a441c80 ffffea00043fa910 ffffea00041ba510
raw: ffff88810dec9800 0000000000100008 00000000f5000000 0000000000000000
head: 057ff00000000240 ffff88801a441c80 ffffea00043fa910 ffffea00041ba510
head: ffff88810dec9800 0000000000100008 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea000437b201 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 5847, tgid 5847 (kworker/u8:2), ts 46832903944, free_ts 46812206323
 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
 __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 5825 tgid 5825 stack trace:
 __free_frozen_pages+0xc71/0xe70
 __slab_free+0x326/0x400
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 __kmalloc_noprof+0x224/0x4f0
 fib6_info_alloc+0x30/0xf0
 ip6_route_info_create+0x142/0x860
 ip6_route_add+0x49/0x1b0
 inet6_addr_add+0x6b2/0xc00
 inet6_rtm_newaddr+0x93d/0xd20
 rtnetlink_rcv_msg+0x7cf/0xb70
 netlink_rcv_skb+0x208/0x470
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270

Memory state around the buggy address:
 ffff88810decab00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88810decab80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88810decac00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88810decac80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88810decad00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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