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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff88812241942a by task syz.2.7117/22212

CPU: 0 UID: 0 PID: 22212 Comm: syz.2.7117 Not tainted syzkaller #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_pc+0x0/0x70
Code: 89 fb e8 23 00 00 00 48 8b 3d c4 49 fe 0b 48 89 de 5b e9 73 98 58 00 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 04 24 65 48 8b 0c 25 08 60 a0 92 65 8b 15 e8 b4
RSP: 0018:ffffc9000176fd18 EFLAGS: 00000246
RAX: 1ffff920002ed9d8 RBX: 0000000000004ec0 RCX: ffff88810f4d5640
RDX: 0000000000000000 RSI: ffffffff8be33660 RDI: ffffc9000176cec0
RBP: ffffc9000176fe78 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed102001c041 R12: dffffc0000000000
R13: 1ffff11021e9ab76 R14: 0000000000003140 R15: ffffc90001768000
 do_exit+0x1883/0x2300
 do_group_exit+0x21c/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x21f7/0x2200
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fce6d18ebe9
Code: Unable to access opcode bytes at 0x7fce6d18ebbf.
RSP: 002b:00007ffc1791e408 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fce6d18ebe9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc1791e46c R08: 000000031791e4ff R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 00000000000008e0
R13: 00000000000927c0 R14: 0000000000039568 R15: 00007ffc1791e4c0
 </TASK>

Allocated by task 21907:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x27a/0x4f0
 copy_splice_read+0x143/0xa50
 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 21907:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 copy_splice_read+0x903/0xa50
 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 ffff888122419400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff888122419400, ffff888122419600)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888122419400 pfn:0x122418
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 ffffea0004461d10 ffffea0004391310
raw: ffff888122419400 000000000010000c 00000000f5000000 0000000000000000
head: 057ff00000000240 ffff88801a441c80 ffffea0004461d10 ffffea0004391310
head: ffff888122419400 000000000010000c 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea0004890601 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 6289, tgid 6288 (syz.1.154), ts 51899462892, free_ts 50873021890
 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/0x370
 ___slab_alloc+0xbeb/0x1410
 __kmalloc_cache_noprof+0x296/0x3d0
 rxrpc_alloc_peer+0x7d/0x330
 rxrpc_service_prealloc_one+0x1f4/0xe20
 afs_charge_preallocation+0x394/0x4e0
 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
page last free pid 5867 tgid 5867 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 __slab_free+0x303/0x3c0
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 __kmalloc_cache_noprof+0x1be/0x3d0
 gro_cells_destroy+0x357/0x430
 ip6gre_dev_free+0x19/0x30
 netdev_run_todo+0xcd7/0xea0
 ops_undo_list+0x3e1/0x990
 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

Memory state around the buggy address:
 ffff888122419300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888122419380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888122419400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888122419480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888122419500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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