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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff88812d7d542a by task modprobe/4468

CPU: 1 UID: 0 PID: 4468 Comm: modprobe Not tainted 6.16.0-syzkaller-06574-gd9104cec3e8f-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: 0033:0x7fea6fff22d8
Code: 66 0f 13 02 66 0f 13 4a 08 48 89 f8 c3 0f 1f 44 00 00 66 0f 6e ce 89 f8 25 ff 0f 00 00 66 0f 60 c9 3d c0 0f 00 00 66 0f 61 c9 <66> 0f 70 c9 00 0f 8f 5d 01 00 00 f3 0f 6f 07 66 0f ef db 66 0f 6f
RSP: 002b:00007ffd7a894038 EFLAGS: 00000287
RAX: 0000000000000480 RBX: 0000000000000073 RCX: 0000000000000000
RDX: 000000000000000c RSI: 0000000000000073 RDI: 000055ebbf495480
RBP: 000055ebbf495480 R08: 000000000000000b R09: 000055ebbf495688
R10: 000055ebbf495680 R11: 000055ebbf495691 R12: 00007fea6ff4e719
R13: 00007fea6ff4e719 R14: 000055ebbf495480 R15: 0000000000000000
 </TASK>

Allocated by task 3711:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 rxrpc_alloc_peer+0x7d/0x330
 rxrpc_service_prealloc_one+0x1f4/0xe20
 afs_charge_preallocation+0x1fa/0x4e0
 afs_open_socket+0x302/0x3a0
 afs_net_init+0x67d/0x880
 ops_init+0x35c/0x5c0
 setup_net+0x10c/0x320
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 13:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x62/0x70
 kfree+0x18e/0x440
 rxrpc_discard_prealloc+0x182/0x890
 rxrpc_listen+0x265/0x370
 afs_close_socket+0xa2/0x3a0
 afs_net_exit+0x60/0x100
 ops_undo_list+0x49a/0x990
 cleanup_net+0x4c5/0x800
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff88812d7d5400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff88812d7d5400, ffff88812d7d5600)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88812d7d4000 pfn:0x12d7d4
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 ffffea0004b7db10 ffffea000438ee10
raw: ffff88812d7d4000 000000000010000e 00000000f5000000 0000000000000000
head: 057ff00000000240 ffff88801a441c80 ffffea0004b7db10 ffffea000438ee10
head: ffff88812d7d4000 000000000010000e 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea0004b5f501 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 17980, tgid 17974 (syz.2.4059), ts 204214206870, free_ts 198695356228
 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
 __genradix_ptr_alloc+0x352/0x4a0
 __genradix_prealloc+0x44/0x90
 sctp_stream_init+0x14b/0x440
 sctp_connect_new_asoc+0x3a6/0x690
 sctp_sendmsg+0x155c/0x2810
 __sock_sendmsg+0x19c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
page last free pid 17562 tgid 17562 stack trace:
 __free_frozen_pages+0xc71/0xe70
 __put_partials+0x161/0x1c0
 put_cpu_partial+0x17c/0x250
 __slab_free+0x2f7/0x400
 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
 __x64_sys_unlink+0x3a/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88812d7d5300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88812d7d5380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88812d7d5400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88812d7d5480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88812d7d5500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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