==================================================================
BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff888020e6c82a by task swapper/1/0

CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-syzkaller-06620-gae633388cae3-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:pv_native_safe_halt+0x13/0x20
Code: 53 e8 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 13 6f 18 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000177de0 EFLAGS: 00000282
RAX: 8189925ee9707300 RBX: ffffffff81969b18 RCX: 8189925ee9707300
RDX: 0000000000000001 RSI: ffffffff8d9792aa RDI: ffffffff8be30a00
RBP: ffffc90000177f20 R08: ffff888136632f5b R09: 1ffff11026cc65eb
R10: dffffc0000000000 R11: ffffed1026cc65ec R12: ffffffff8fa07bf0
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff1102001d000
 default_idle+0x13/0x20
 default_idle_call+0x74/0xb0
 do_idle+0x1e8/0x510
 cpu_startup_entry+0x44/0x60
 start_secondary+0x101/0x110
 common_startup_64+0x13e/0x147
 </TASK>

Allocated by task 21146:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 rose_add_node+0x23a/0xde0
 rose_rt_ioctl+0xa48/0xfb0
 rose_ioctl+0x3ce/0x8b0
 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

Freed by task 4252:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x62/0x70
 kfree+0x18e/0x440
 rose_rt_device_down+0x473/0x4c0
 rose_device_event+0x603/0x6a0
 notifier_call_chain+0x1b6/0x3e0
 __dev_notify_flags+0x18d/0x2e0
 netif_change_flags+0xe8/0x1a0
 dev_change_flags+0x130/0x260
 dev_ioctl+0x7b4/0x1150
 sock_do_ioctl+0x22c/0x300
 sock_ioctl+0x576/0x790
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888020e6c800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff888020e6c800, ffff888020e6ca00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888020e6e000 pfn:0x20e6c
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 ffffea00009b8710 ffffea0000d7bd10
raw: ffff888020e6e000 000000000010000b 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801a441c80 ffffea00009b8710 ffffea0000d7bd10
head: ffff888020e6e000 000000000010000b 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000839b01 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 5871, tgid 5871 (kworker/u8:4), ts 58999351054, free_ts 58946988528
 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 5881 tgid 5881 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
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 getname_flags+0xb8/0x540
 vfs_fstatat+0x43/0x170
 __x64_sys_newfstatat+0x116/0x190
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888020e6c700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888020e6c780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888020e6c800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888020e6c880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888020e6c900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
