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BUG: KASAN: null-ptr-deref in drop_buffers+0x65/0x4f0
Read of size 4 at addr 0000000000000060 by task syz.7.3505/1324

CPU: 0 UID: 0 PID: 1324 Comm: syz.7.3505 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
 kasan_report+0x118/0x150
 kasan_check_range+0x2b0/0x2c0
 drop_buffers+0x65/0x4f0
 try_to_free_buffers+0x1e1/0x2d0
 shrink_folio_list+0x20ac/0x4cd0
 evict_folios+0x47f2/0x58b0
 try_to_shrink_lruvec+0x8a3/0xb50
 shrink_one+0x21b/0x7c0
 shrink_node+0x314e/0x3760
 do_try_to_free_pages+0x668/0x1960
 try_to_free_pages+0x8a2/0xdd0
 __alloc_pages_direct_reclaim+0x144/0x300
 __alloc_pages_slowpath+0x5ff/0xce0
 __alloc_frozen_pages_noprof+0x319/0x370
 alloc_pages_mpol+0x232/0x4a0
 alloc_pages_noprof+0xa9/0x190
 stack_depot_save_flags+0x777/0x860
 save_stack+0x103/0x1f0
 __set_page_owner+0x8d/0x4a0
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_pages_slowpath+0x2fe/0xce0
 __alloc_frozen_pages_noprof+0x319/0x370
 alloc_pages_mpol+0x232/0x4a0
 vma_alloc_folio_noprof+0xe4/0x200
 folio_prealloc+0x30/0x180
 do_wp_page+0x1231/0x5800
 __handle_mm_fault+0x1033/0x5440
 handle_mm_fault+0x40a/0x8e0
 do_user_addr_fault+0x764/0x1390
 exc_page_fault+0x76/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0010:__put_user_4+0xd/0x20
Code: 66 89 01 31 c9 0f 1f 00 e9 50 44 03 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 89 cb 48 c1 fb 3f 48 09 d9 0f 1f 00 <89> 01 31 c9 0f 1f 00 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000b1a7e48 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000200000000280
RDX: 0000000000000000 RSI: ffffffff8be33660 RDI: ffff888106acb980
RBP: ffffc9000b1a7f48 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f47067 R12: 1ffff11020d59804
R13: 1ffff92001634fd4 R14: ffff888106acb980 R15: dffffc0000000000
 schedule_tail+0x9e/0xc0
 ret_from_fork+0x92/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
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