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BUG: KASAN: slab-out-of-bounds in change_page_attr_set_clr+0x625/0xfc0
Read of size 8 at addr ffff88810f6c2520 by task syz.3.342/6896

CPU: 1 UID: 0 PID: 6896 Comm: syz.3.342 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:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 change_page_attr_set_clr+0x625/0xfc0
 _set_pages_array+0x145/0x270
 drm_gem_shmem_get_pages_locked+0x2d0/0x440
 drm_gem_shmem_mmap+0x193/0x460
 drm_gem_mmap_obj+0x18a/0x4e0
 drm_gem_mmap+0x384/0x640
 mmap_region+0x18b4/0x2110
 do_mmap+0xc45/0x10d0
 vm_mmap_pgoff+0x2a6/0x4d0
 ksys_mmap_pgoff+0x51f/0x760
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fca85f8ec29
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:00007fca86dc5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fca861d5fa0 RCX: 00007fca85f8ec29
RDX: 0000000000000004 RSI: 0000000000004000 RDI: 0000200000001000
RBP: 00007fca86011e41 R08: 0000000000000003 R09: 0000000100000000
R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fca861d6038 R14: 00007fca861d5fa0 R15: 00007ffd00e1b9e8
 </TASK>

Allocated by task 6896:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kvmalloc_node_noprof+0x5cd/0x910
 drm_gem_get_pages+0x166/0xa20
 drm_gem_shmem_get_pages_locked+0x201/0x440
 drm_gem_shmem_mmap+0x193/0x460
 drm_gem_mmap_obj+0x18a/0x4e0
 drm_gem_mmap+0x384/0x640
 mmap_region+0x18b4/0x2110
 do_mmap+0xc45/0x10d0
 vm_mmap_pgoff+0x2a6/0x4d0
 ksys_mmap_pgoff+0x51f/0x760
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88810f6c2400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes to the right of
 allocated 288-byte region [ffff88810f6c2400, ffff88810f6c2520)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10f6c0
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801ac41c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801ac41c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea00043db001 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 5903, tgid 5903 (kworker/u9:3), ts 66063775446, free_ts 66048966824
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x2365/0x2440
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x96/0x3a0
 ___slab_alloc+0xe94/0x1920
 __slab_alloc+0x65/0x100
 __kmalloc_cache_noprof+0x411/0x6f0
 alloc_bprm+0x7d/0x5c0
 kernel_execve+0x9b/0x9f0
 call_usermodehelper_exec_async+0x210/0x360
 ret_from_fork+0x4bc/0x870
 ret_from_fork_asm+0x1a/0x30
page last free pid 5902 tgid 5902 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 __slab_free+0x2e7/0x390
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_noprof+0x367/0x6e0
 vm_area_alloc+0x24/0x140
 mmap_region+0xdcd/0x2110
 do_mmap+0xc45/0x10d0
 vm_mmap_pgoff+0x2a6/0x4d0
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88810f6c2400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88810f6c2480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88810f6c2500: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff88810f6c2580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88810f6c2600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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