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BUG: KASAN: use-after-free in sysv_new_inode+0xfd3/0x1170 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff88807b27d1ce by task syz.3.3145/15359

CPU: 0 PID: 15359 Comm: syz.3.3145 Not tainted 6.10.0-rc7-syzkaller-00012-g34afb82a3c67 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 sysv_new_inode+0xfd3/0x1170 fs/sysv/ialloc.c:153
 sysv_mknod+0x4e/0xe0 fs/sysv/namei.c:53
 lookup_open fs/namei.c:3505 [inline]
 open_last_lookups fs/namei.c:3574 [inline]
 path_openat+0x1a86/0x35f0 fs/namei.c:3810
 do_filp_open+0x235/0x490 fs/namei.c:3840
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1413
 do_sys_open fs/open.c:1428 [inline]
 __do_sys_openat fs/open.c:1444 [inline]
 __se_sys_openat fs/open.c:1439 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1439
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f19e3d75bd9
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:00007f19e4bea048 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f19e3f03f60 RCX: 00007f19e3d75bd9
RDX: 000000000000275a RSI: 0000000020000080 RDI: ffffffffffffff9c
RBP: 00007f19e3de4e60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f19e3f03f60 R15: 00007fffc17f9188
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x636e2 pfn:0x7b27d
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000
raw: 00000000000636e2 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 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 15442, tgid 15441 (syz.5.3174), ts 1303319348092, free_ts 1384425528919
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1473
 prep_new_page mm/page_alloc.c:1481 [inline]
 get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3425
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4683
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_pages_noprof mm/mempolicy.c:2336 [inline]
 folio_alloc_noprof+0x128/0x180 mm/mempolicy.c:2343
 filemap_alloc_folio_noprof+0xdf/0x500 mm/filemap.c:1008
 do_read_cache_folio+0xed/0x820 mm/filemap.c:3752
 do_read_cache_page+0x30/0x200 mm/filemap.c:3854
 read_mapping_page include/linux/pagemap.h:900 [inline]
 dir_get_page fs/sysv/dir.c:64 [inline]
 sysv_find_entry+0x1af/0x410 fs/sysv/dir.c:157
 sysv_inode_by_name+0x98/0x1f0 fs/sysv/dir.c:374
 sysv_lookup+0x6b/0xe0 fs/sysv/namei.c:38
 lookup_open fs/namei.c:3483 [inline]
 open_last_lookups fs/namei.c:3574 [inline]
 path_openat+0x11c2/0x35f0 fs/namei.c:3810
 do_filp_open+0x235/0x490 fs/namei.c:3840
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1413
 do_sys_open fs/open.c:1428 [inline]
 __do_sys_openat fs/open.c:1444 [inline]
 __se_sys_openat fs/open.c:1439 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1439
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
page last free pid 15442 tgid 15441 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1093 [inline]
 free_unref_folios+0xf23/0x19e0 mm/page_alloc.c:2637
 shrink_folio_list+0x33cd/0x8f70 mm/vmscan.c:1446
 evict_folios+0xb2e/0x2710 mm/vmscan.c:4553
 try_to_shrink_lruvec+0xb6b/0xe90 mm/vmscan.c:4749
 lru_gen_shrink_lruvec mm/vmscan.c:4892 [inline]
 shrink_lruvec+0x586/0x2f90 mm/vmscan.c:5669
 shrink_node_memcgs mm/vmscan.c:5889 [inline]
 shrink_node+0xa18/0x3fe0 mm/vmscan.c:5924
 shrink_zones mm/vmscan.c:6168 [inline]
 do_try_to_free_pages+0x77d/0x1c40 mm/vmscan.c:6230
 try_to_free_mem_cgroup_pages+0x465/0xac0 mm/vmscan.c:6545
 try_charge_memcg+0x701/0x1840 mm/memcontrol.c:2944
 obj_cgroup_charge_pages mm/memcontrol.c:3416 [inline]
 obj_cgroup_charge+0x38a/0x630 mm/memcontrol.c:3705
 __memcg_slab_post_alloc_hook+0x1b1/0x7e0 mm/memcontrol.c:3766
 memcg_slab_post_alloc_hook mm/slub.c:2104 [inline]
 slab_post_alloc_hook mm/slub.c:3963 [inline]
 slab_alloc_node mm/slub.c:4002 [inline]
 kmem_cache_alloc_noprof+0x1de/0x2a0 mm/slub.c:4009
 alloc_buffer_head+0x2a/0x290 fs/buffer.c:3028
 folio_alloc_buffers+0x241/0x5b0 fs/buffer.c:931
 create_empty_buffers+0x3a/0x740 fs/buffer.c:1673
 block_read_full_folio+0x258/0xe10 fs/buffer.c:2388

Memory state around the buggy address:
 ffff88807b27d080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807b27d100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88807b27d180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff88807b27d200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807b27d280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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