syzbot

==================================================================
BUG: KASAN: use-after-free in sysv_new_inode+0xed4/0x1190 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff8880550b11ce by task syz-executor.3/12581

CPU: 1 PID: 12581 Comm: syz-executor.3 Not tainted 6.9.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 sysv_new_inode+0xed4/0x1190 fs/sysv/ialloc.c:153
 sysv_mknod fs/sysv/namei.c:53 [inline]
 sysv_create+0x20/0xf0 fs/sysv/namei.c:67
 lookup_open.isra.0+0x10a4/0x13c0 fs/namei.c:3497
 open_last_lookups fs/namei.c:3566 [inline]
 path_openat+0x92f/0x2990 fs/namei.c:3796
 do_filp_open+0x1dc/0x430 fs/namei.c:3826
 do_sys_openat2+0x17a/0x1e0 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_creat fs/open.c:1497 [inline]
 __se_sys_creat fs/open.c:1491 [inline]
 __x64_sys_creat+0xcd/0x120 fs/open.c:1491
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7ba687dca9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7ba757e0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f7ba69abf80 RCX: 00007f7ba687dca9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000140
RBP: 00007f7ba68c947e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f7ba69abf80 R15: 00007ffd1a235438
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x550b1
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 dead000000000100 dead000000000122 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 0x100cca(GFP_HIGHUSER_MOVABLE), pid 29839, tgid -1440452774 (syz-executor.1), ts 29840, free_ts 2237463585463
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317
 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575
 alloc_pages_mpol+0x275/0x610 mm/mempolicy.c:2264
 shmem_alloc_folio+0x114/0x150 mm/shmem.c:1628
 shmem_alloc_and_add_folio+0x14f/0x6f0 mm/shmem.c:1668
 shmem_get_folio_gfp+0x685/0x13e0 mm/shmem.c:2055
 shmem_get_folio mm/shmem.c:2160 [inline]
 shmem_write_begin+0x15a/0x370 mm/shmem.c:2744
 generic_perform_write+0x275/0x620 mm/filemap.c:3974
 shmem_file_write_iter+0x114/0x140 mm/shmem.c:2920
 call_write_iter include/linux/fs.h:2110 [inline]
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0x6de/0x1100 fs/read_write.c:590
 ksys_write+0x12f/0x260 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 29446 tgid 29446 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347
 free_unref_folios+0x256/0xad0 mm/page_alloc.c:2536
 folios_put_refs+0x487/0x6d0 mm/swap.c:1034
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x5a1/0x1170 mm/shmem.c:1005
 shmem_truncate_range mm/shmem.c:1114 [inline]
 shmem_evict_inode+0x3a3/0xbb0 mm/shmem.c:1242
 evict+0x2f0/0x6c0 fs/inode.c:667
 iput_final fs/inode.c:1741 [inline]
 iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
 iput+0x5c/0x80 fs/inode.c:1757
 dentry_unlink_inode+0x295/0x440 fs/dcache.c:400
 __dentry_kill+0x1d0/0x600 fs/dcache.c:603
 dput.part.0+0x4b1/0x9b0 fs/dcache.c:845
 dput+0x1f/0x30 fs/dcache.c:835
 __fput+0x3bc/0xb80 fs/file_table.c:430
 task_work_run+0x151/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89

Memory state around the buggy address:
 ffff8880550b1080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880550b1100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880550b1180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff8880550b1200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880550b1280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
syz-executor.3: attempt to access beyond end of device
loop3: rw=0, sector=6491536, nr_sectors = 2 limit=64
Buffer I/O error on dev loop3, logical block 3245768, async page read
syz-executor.3: attempt to access beyond end of device
loop3: rw=0, sector=17666806, nr_sectors = 2 limit=64
Buffer I/O error on dev loop3, logical block 8833403, async page read
syz-executor.3: attempt to access beyond end of device
loop3: rw=0, sector=26539618, nr_sectors = 2 limit=64
Buffer I/O error on dev loop3, logical block 13269809, async page read
syz-executor.3: attempt to access beyond end of device
loop3: rw=0, sector=16147212, nr_sectors = 2 limit=64
Buffer I/O error on dev loop3, logical block 8073606, async page read