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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff88802ed3042a by task syz.0.3784/17515

CPU: 0 UID: 0 PID: 17515 Comm: syz.0.3784 Not tainted 6.16.0-rc5-syzkaller-00212-g9f735b6f8a77-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+0xd2/0x2b0
 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:vprintk_store+0xabc/0xd00
Code: e8 09 3c 1f 00 48 bb 00 00 00 00 00 fc ff df 4d 85 f6 75 07 e8 f5 3b 1f 00 eb 06 e8 ee 3b 1f 00 fb 48 c7 44 24 60 0e 36 e0 45 <49> c7 04 1c 00 00 00 00 49 c7 44 1c 09 00 00 00 00 49 c7 44 1c 14
RSP: 0018:ffffc90002b3f2a0 EFLAGS: 00000287
RAX: ffffffff81a0f052 RBX: dffffc0000000000 RCX: 0000000000080000
RDX: ffffc9000fab1000 RSI: 0000000000000b6b RDI: 0000000000000b6c
RBP: ffffc90002b3f4b0 R08: ffffffff8fa1d5f7 R09: 1ffffffff1f43abe
R10: dffffc0000000000 R11: fffffbfff1f43abf R12: 1ffff92000567e60
R13: 0000000000000024 R14: 0000000000000200 R15: ffff88804b024281
 vprintk_emit+0x21e/0x7a0
 _printk+0xcf/0x120
 netdev_info+0x10a/0x160
 __dev_set_promiscuity+0x307/0x740
 __dev_change_flags+0x41b/0x6d0
 netif_change_flags+0x88/0x1a0
 dev_change_flags+0x130/0x260
 devinet_ioctl+0xbb4/0x1b50
 inet_ioctl+0x3c0/0x4c0
 sock_do_ioctl+0xdc/0x300
 sock_ioctl+0x576/0x790
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feedcb8e9a9
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:00007feeda9f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007feedcdb5fa0 RCX: 00007feedcb8e9a9
RDX: 0000200000000040 RSI: 0000000000008914 RDI: 0000000000000007
RBP: 00007feedcc10ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007feedcdb5fa0 R15: 00007ffcac42e4d8
 </TASK>

Allocated by task 17508:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x27a/0x4f0
 fib6_info_alloc+0x30/0xf0
 ip6_route_info_create+0x142/0x860
 ip6_route_add+0x49/0x1b0
 inet6_rtm_newroute+0x1cf/0x18c0
 rtnetlink_rcv_msg+0x7cf/0xb70
 netlink_rcv_skb+0x208/0x470
 netlink_unicast+0x75c/0x8e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 17511:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x62/0x70
 kfree+0x18e/0x440
 rcu_core+0xca8/0x1710
 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

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 call_rcu+0x157/0x9c0
 ip6_route_info_create_nh+0x211/0xab0
 ip6_route_add+0x6e/0x1b0
 inet6_rtm_newroute+0x1cf/0x18c0
 rtnetlink_rcv_msg+0x7cf/0xb70
 netlink_rcv_skb+0x208/0x470
 netlink_unicast+0x75c/0x8e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802ed30400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff88802ed30400, ffff88802ed30600)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2ed30
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801a441c80 ffffea0000bb5200 dead000000000003
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801a441c80 ffffea0000bb5200 dead000000000003
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000bb4c01 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5839, tgid 5839 (syz-executor), ts 59156258138, 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/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_permanent_addr+0x67f/0x9d0
 addrconf_notify+0x887/0x1010
 notifier_call_chain+0x1b6/0x3e0
 __dev_notify_flags+0x18d/0x2e0
 netif_change_flags+0xe8/0x1a0
 do_setlink+0xc55/0x41c0
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802ed30300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802ed30380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802ed30400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88802ed30480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802ed30500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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