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BUG: KASAN: use-after-free in hpfs_bplus_lookup+0x4f4/0x880 fs/hpfs/anode.c:38
Read of size 4 at addr ffff88806ea70008 by task syz.2.5131/27054

CPU: 0 UID: 0 PID: 27054 Comm: syz.2.5131 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 hpfs_bplus_lookup+0x4f4/0x880 fs/hpfs/anode.c:38
 hpfs_bmap+0x230/0x4e0 fs/hpfs/file.c:54
 hpfs_get_block+0xa8/0x6e0 fs/hpfs/file.c:87
 do_mpage_readpage+0x801/0x1980 fs/mpage.c:221
 mpage_readahead+0x3f9/0x810 fs/mpage.c:370
 read_pages+0x193/0x5a0 mm/readahead.c:163
 page_cache_ra_unbounded+0x794/0xa10 mm/readahead.c:304
 do_page_cache_ra mm/readahead.c:334 [inline]
 page_cache_ra_order+0xae4/0xe80 mm/readahead.c:538
 filemap_get_pages+0x4c0/0x1ef0 mm/filemap.c:2696
 filemap_read+0x447/0x1230 mm/filemap.c:2806
 __kernel_read+0x504/0x9b0 fs/read_write.c:532
 integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28
 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:222 [inline]
 ima_calc_file_hash+0x446/0x860 security/integrity/ima/ima_crypto.c:280
 ima_collect_measurement+0x51d/0x9c0 security/integrity/ima/ima_api.c:300
 process_measurement+0x12cd/0x1c80 security/integrity/ima/ima_main.c:425
 ima_file_check+0xe1/0x130 security/integrity/ima/ima_main.c:685
 security_file_post_open+0xb3/0x260 security/security.c:2755
 do_open fs/namei.c:4701 [inline]
 path_openat+0x2e4d/0x3860 fs/namei.c:4858
 do_file_open+0x23e/0x4a0 fs/namei.c:4887
 do_sys_openat2+0x113/0x200 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_open fs/open.c:1378 [inline]
 __se_sys_open fs/open.c:1374 [inline]
 __x64_sys_open+0x11e/0x150 fs/open.c:1374
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1fadf9ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1faee59028 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f1fae216090 RCX: 00007f1fadf9ce59
RDX: 0000000000000002 RSI: 0000000000080540 RDI: 0000200000000080
RBP: 00007f1fae032d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1fae216128 R14: 00007f1fae216090 R15: 00007ffe877bcf28
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x3e87 pfn:0x6ea70
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001ba9b88 ffffea0001ba9c48 0000000000000000
raw: 0000000000003e87 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x29c2(GFP_NOWAIT|__GFP_HIGHMEM|__GFP_IO|__GFP_FS|__GFP_ZERO), pid 27035, tgid 27028 (syz.8.5123), ts 1712440276001, free_ts 1712637889372
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1853
 prep_new_page mm/page_alloc.c:1861 [inline]
 get_page_from_freelist+0x2593/0x2610 mm/page_alloc.c:3941
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5221
 alloc_pages_mpol+0x235/0x490 mm/mempolicy.c:2490
 alloc_frozen_pages_noprof mm/mempolicy.c:2561 [inline]
 alloc_pages_noprof+0xac/0x2a0 mm/mempolicy.c:2581
 vm_area_alloc_pages mm/vmalloc.c:3653 [inline]
 __vmalloc_area_node mm/vmalloc.c:3878 [inline]
 __vmalloc_node_range_noprof+0x7a7/0x1750 mm/vmalloc.c:4064
 vmalloc_user_noprof+0xad/0xe0 mm/vmalloc.c:4218
 vb2_vmalloc_alloc+0xef/0x360 drivers/media/common/videobuf2/videobuf2-vmalloc.c:47
 __vb2_buf_mem_alloc drivers/media/common/videobuf2/videobuf2-core.c:242 [inline]
 __vb2_queue_alloc+0x9c5/0x15a0 drivers/media/common/videobuf2/videobuf2-core.c:523
 vb2_core_reqbufs+0xc1f/0x1410 drivers/media/common/videobuf2/videobuf2-core.c:958
 v4l2_m2m_reqbufs drivers/media/v4l2-core/v4l2-mem2mem.c:579 [inline]
 v4l2_m2m_ioctl_reqbufs+0x10d/0x200 drivers/media/v4l2-core/v4l2-mem2mem.c:1378
 __video_do_ioctl+0xadb/0xca0 drivers/media/v4l2-core/v4l2-ioctl.c:3133
 video_usercopy+0x876/0x1450 drivers/media/v4l2-core/v4l2-ioctl.c:3475
 v4l2_ioctl+0x18d/0x1e0 drivers/media/v4l2-core/v4l2-dev.c:366
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
page last free pid 27028 tgid 27028 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1397 [inline]
 __free_frozen_pages+0xc1c/0xd30 mm/page_alloc.c:2938
 vfree+0x1d1/0x2f0 mm/vmalloc.c:3472
 vb2_vmalloc_put+0x68/0xb0 drivers/media/common/videobuf2/videobuf2-vmalloc.c:68
 __vb2_buf_mem_free+0x119/0x2d0 drivers/media/common/videobuf2/videobuf2-core.c:275
 __vb2_free_mem drivers/media/common/videobuf2/videobuf2-core.c:571 [inline]
 __vb2_queue_free+0x414/0xb00 drivers/media/common/videobuf2/videobuf2-core.c:599
 vb2_core_queue_release+0x6b/0x150 drivers/media/common/videobuf2/videobuf2-core.c:2679
 v4l2_m2m_ctx_release+0x2a/0x40 drivers/media/v4l2-core/v4l2-mem2mem.c:1286
 vicodec_release+0x96/0x110 drivers/media/test-drivers/vicodec/vicodec-core.c:1947
 v4l2_release+0x1af/0x370 drivers/media/v4l2-core/v4l2-dev.c:468
 __fput+0x44f/0xa60 fs/file_table.c:510
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0x193/0x680 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88806ea6ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88806ea6ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88806ea70000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                      ^
 ffff88806ea70080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806ea70100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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