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BUG: KASAN: slab-use-after-free in ax25_find_cb+0x2cf/0x3a0
Read of size 1 at addr ffff888173f994c0 by task syz.0.14173/5793

CPU: 0 UID: 0 PID: 5793 Comm: syz.0.14173 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+0xe8/0x150
 print_report+0xba/0x230
 kasan_report+0x117/0x150
 ax25_find_cb+0x2cf/0x3a0
 ax25_send_frame+0x2f6/0x9f0
 rose_send_frame+0x111/0x220
 rose_t0timer_expiry+0x143/0x350
 call_timer_fn+0x192/0x5a0
 __run_timer_base+0x652/0x8b0
 run_timer_softirq+0xb7/0x170
 handle_softirqs+0x22a/0x7c0
 __irq_exit_rcu+0x5f/0x150
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:save_stack+0xad/0x230
Code: f3 f3 f3 f3 4b 89 44 27 10 e8 df 2f 8f ff 4b c7 44 27 04 00 00 00 00 4b c7 44 27 0c 00 00 00 00 ba 80 00 00 00 48 89 df 31 f6 <e8> 7e 2a f6 ff 65 48 8b 1d 3e 1e 9c 10 48 81 c3 d0 05 00 00 49 89
RSP: 0018:ffffc90005dbef40 EFLAGS: 00000246
RAX: ffffffff823351a1 RBX: ffffc90005dbef80 RCX: 0000000000080000
RDX: 0000000000000080 RSI: 0000000000000000 RDI: ffffc90005dbef80
RBP: ffffc90005dbf070 R08: ffffffff8fced877 R09: 0000000000000000
R10: ffffed1022c46400 R11: fffffbfff1f9db0f R12: dffffc0000000000
R13: dffffc0000000000 R14: 00000087f40112f1 R15: 1ffff92000bb7dec
 __set_page_owner+0x8d/0x4c0
 post_alloc_hook+0x228/0x280
 get_page_from_freelist+0x24dc/0x2580
 __alloc_frozen_pages_noprof+0x18d/0x380
 alloc_pages_mpol+0x232/0x4a0
 folio_alloc_mpol_noprof+0x39/0x70
 shmem_alloc_and_add_folio+0x445/0xf80
 shmem_get_folio_gfp+0x5a9/0x1670
 shmem_fault+0x179/0x390
 __do_fault+0x138/0x390
 do_pte_missing+0x2206/0x3310
 handle_mm_fault+0x1b8c/0x32a0
 __get_user_pages+0x165b/0x29d0
 populate_vma_page_range+0x2be/0x3c0
 __mm_populate+0x25f/0x390
 vm_mmap_pgoff+0x3aa/0x4f0
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f69e6b9acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f69e7992028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f69e6e15fa0 RCX: 00007f69e6b9acb9
RDX: b635773f07ebbeef RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f69e6c08bf7 R08: ffffffffffffffff R09: 00000000215eb000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f69e6e16038 R14: 00007f69e6e15fa0 R15: 00007ffe3a818f68
 </TASK>

Allocated by task 26411:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x3d1/0x6e0
 rose_add_node+0x471/0xf00
 rose_rt_ioctl+0xd35/0x12a0
 rose_ioctl+0x3fb/0x8f0
 sock_do_ioctl+0x101/0x320
 sock_ioctl+0x5c6/0x7f0
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5885:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5c/0x80
 kfree+0x1be/0x650
 rose_timer_expiry+0x4c3/0x600
 call_timer_fn+0x192/0x5a0
 __run_timer_base+0x652/0x8b0
 run_timer_softirq+0xb7/0x170
 handle_softirqs+0x22a/0x7c0
 __irq_exit_rcu+0x5f/0x150
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20

The buggy address belongs to the object at ffff888173f99480
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 64 bytes inside of
 freed 96-byte region [ffff888173f99480, ffff888173f994e0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888173f99900 pfn:0x173f99
flags: 0x57ff00000000200(workingset|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000200 ffff888100041280 ffffea0005b51750 ffffea0006f58290
raw: ffff888173f99900 0000000000200018 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 1, tgid 1 (swapper/0), ts 24642155280, free_ts 24489922576
 post_alloc_hook+0x228/0x280
 get_page_from_freelist+0x24dc/0x2580
 __alloc_frozen_pages_noprof+0x18d/0x380
 allocate_slab+0x7a/0x3a0
 ___slab_alloc+0xd82/0x1760
 __slab_alloc+0x65/0x100
 __kmalloc_cache_node_noprof+0x493/0x6d0
 __alloc_workqueue+0x6a8/0x1b80
 alloc_workqueue_noprof+0xe3/0x210
 batadv_init+0x131/0x190
 do_one_initcall+0x250/0x840
 do_initcall_level+0x104/0x190
 do_initcalls+0x59/0xa0
 kernel_init_freeable+0x2a6/0x3d0
 kernel_init+0x1d/0x1d0
 ret_from_fork+0x51b/0xa40
page last free pid 10 tgid 10 stack trace:
 __free_frozen_pages+0xbb0/0xd10
 vfree+0x25a/0x400
 delayed_vfree_work+0x55/0x80
 process_scheduled_works+0xaec/0x17a0
 worker_thread+0x89f/0xd90
 kthread+0x726/0x8b0
 ret_from_fork+0x51b/0xa40
 ret_from_fork_asm+0x1a/0x30

Memory state around the buggy address:
 ffff888173f99380: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
 ffff888173f99400: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
>ffff888173f99480: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                                           ^
 ffff888173f99500: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
 ffff888173f99580: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
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