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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff88810bd25c2a by task syz.0.6438/20746

CPU: 1 UID: 0 PID: 20746 Comm: syz.0.6438 Not tainted 6.16.0-syzkaller-06574-gd9104cec3e8f #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_unlock+0x0/0x10
Code: fa 31 ff e8 02 e8 1e f6 e9 a9 fd ff ff cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 34 24 eb 16 66 0f 1f 44 00 00 90 90 90 90 90 90
RSP: 0018:ffffc90002adf6d8 EFLAGS: 00000293
RAX: ffffffff89512b7f RBX: ffff888112fa4200 RCX: ffff888020511cc0
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff88811847eb70
RBP: ffffc90002adf870 R08: ffff88803e000267 R09: 1ffff11007c0004c
R10: dffffc0000000000 R11: ffffed1007c0004d R12: ffff88803e000180
R13: 0000000000000002 R14: dffffc0000000000 R15: 1ffff9200055beec
 __unix_dgram_recvmsg+0xa03/0xd60
 sock_recvmsg_nosec+0x186/0x1c0
 ____sys_recvmsg+0x3aa/0x460
 ___sys_recvmsg+0x1b5/0x510
 do_recvmmsg+0x307/0x770
 __x64_sys_recvmmsg+0x190/0x240
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe335f8ebe9
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:00007fe336dab038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fe3361b6090 RCX: 00007fe335f8ebe9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000007
RBP: 00007fe336011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe3361b6128 R14: 00007fe3361b6090 R15: 00007ffd3982eea8
 </TASK>

Allocated by task 20656:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x27a/0x4f0
 copy_splice_read+0x143/0x9b0
 splice_direct_to_actor+0x4d0/0xcc0
 do_splice_direct+0x181/0x270
 do_sendfile+0x4da/0x7e0
 __se_sys_sendfile64+0x13e/0x190
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 20656:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x62/0x70
 kfree+0x18e/0x440
 copy_splice_read+0x881/0x9b0
 splice_direct_to_actor+0x4d0/0xcc0
 do_splice_direct+0x181/0x270
 do_sendfile+0x4da/0x7e0
 __se_sys_sendfile64+0x13e/0x190
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88810bd25c00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff88810bd25c00, ffff88810bd25e00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10bd24
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801a441c80 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801a441c80 0000000000000000 dead000000000001
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea00042f4901 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 5818, tgid 5818 (syz-executor), ts 47939556071, free_ts 47912217570
 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_noprof+0x305/0x4f0
 fib6_info_alloc+0x30/0xf0
 ip6_route_info_create+0x142/0x860
 ip6_route_add+0x49/0x1b0
 addrconf_add_dev+0x24f/0x340
 addrconf_init_auto_addrs+0x57c/0xa30
 addrconf_notify+0xacc/0x1010
 notifier_call_chain+0x1b6/0x3e0
 __dev_notify_flags+0x18d/0x2e0
 netif_change_flags+0xe8/0x1a0
page last free pid 5852 tgid 5852 stack trace:
 __free_frozen_pages+0xc71/0xe70
 stack_depot_save_flags+0x445/0x900
 ref_tracker_free+0xfe/0x7d0
 fib_nh_common_release+0x4f/0x420
 fib6_info_destroy_rcu+0xca/0x1c0
 rcu_core+0xca8/0x1710
 handle_softirqs+0x286/0x870
 do_softirq+0xec/0x180
 __local_bh_enable_ip+0x17d/0x1c0
 ipv6_get_lladdr+0x2aa/0x3f0
 mld_newpack+0x420/0xc40
 add_grhead+0x5a/0x2a0
 add_grec+0x1452/0x1740
 mld_ifc_work+0x6ed/0xd60
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0

Memory state around the buggy address:
 ffff88810bd25b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88810bd25b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88810bd25c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88810bd25c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88810bd25d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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