loop1: rw=0, want=6491538, limit=128
Buffer I/O error on dev loop1, logical block 3245768, async page read
==================================================================
BUG: KASAN: use-after-free in sysv_new_block+0x788/0x960 fs/sysv/balloc.c:113
Read of size 4 at addr ffff8880691400c8 by task syz.1.16/5006

CPU: 1 PID: 5006 Comm: syz.1.16 Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 sysv_new_block+0x788/0x960 fs/sysv/balloc.c:113
 alloc_branch fs/sysv/itree.c:134 [inline]
 get_block+0x2e7/0x1790 fs/sysv/itree.c:253
 __block_write_begin_int+0x60b/0x1650 fs/buffer.c:2012
 __block_write_begin fs/buffer.c:2062 [inline]
 block_write_begin+0x4f/0xc0 fs/buffer.c:2122
 sysv_write_begin+0x36/0x70 fs/sysv/itree.c:487
 __page_symlink+0x15b/0x2a0 fs/namei.c:5177
 sysv_symlink+0xcb/0x180 fs/sysv/namei.c:86
 vfs_symlink+0x247/0x3d0 fs/namei.c:4429
 do_symlinkat+0x1fd/0x600 fs/namei.c:4458
 __do_sys_symlink fs/namei.c:4480 [inline]
 __se_sys_symlink fs/namei.c:4478 [inline]
 __x64_sys_symlink+0x7a/0x90 fs/namei.c:4478
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f717e942ff9
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:00007f717dbc3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007f717eafaf80 RCX: 00007f717e942ff9
RDX: 0000000000000000 RSI: 00000000200059c0 RDI: 00000000200049c0
RBP: 00007f717e9b5296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f717eafaf80 R15: 00007fff0beaf018
 </TASK>

The buggy address belongs to the page:
page:ffffea0001a45000 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x69140
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001a52a08 ffffea0001a4f208 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x1100cca(GFP_HIGHUSER_MOVABLE), pid 5012, ts 108041466754, free_ts 108043411494
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5464
 alloc_pages_vma+0x39a/0x800 mm/mempolicy.c:2146
 wp_page_copy+0x24e/0x2070 mm/memory.c:3054
 handle_pte_fault mm/memory.c:4666 [inline]
 __handle_mm_fault mm/memory.c:4783 [inline]
 handle_mm_fault+0x2a3d/0x5960 mm/memory.c:4881
 do_user_addr_fault arch/x86/mm/fault.c:1357 [inline]
 handle_page_fault arch/x86/mm/fault.c:1445 [inline]
 exc_page_fault+0x271/0x700 arch/x86/mm/fault.c:1501
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433
 release_pages+0x1bb9/0x1f40 mm/swap.c:963
 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:240 [inline]
 tlb_flush_mmu mm/mmu_gather.c:247 [inline]
 tlb_finish_mmu+0x177/0x320 mm/mmu_gather.c:338
 exit_mmap+0x3cd/0x670 mm/mmap.c:3188
 __mmput+0x112/0x3b0 kernel/fork.c:1127
 exit_mm+0x688/0x7f0 kernel/exit.c:550
 do_exit+0x626/0x2480 kernel/exit.c:861
 do_group_exit+0x144/0x310 kernel/exit.c:996
 __do_sys_exit_group kernel/exit.c:1007 [inline]
 __se_sys_exit_group kernel/exit.c:1005 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1005
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff88806913ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888069140000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888069140080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff888069140100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888069140180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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