syzbot


KASAN: use-after-free Read in ntfs_readpage

Status: upstream: reported C repro on 2023/03/18 08:03
Bug presence: origin:upstream
Labels: missing-backport
[Documentation on labels]
Reported-by: syzbot+ba146e220a3be3513bdc@syzkaller.appspotmail.com
First crash: 1089d, last: 4d03h
Fix commit to backport (bisect log) :
tree: upstream
commit 7ffa8f3d30236e0ab897c30bdb01224ff1fe1c89
Author: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Mon Jan 15 07:20:25 2024 +0000

  fs: Remove NTFS classic

  
Fix bisection: failed (error log, bisect log)
  
Bug presence (3)
Date Name Commit Repro Result
2024/04/21 linux-5.15.y (ToT) c52b9710c83d C [report] KASAN: use-after-free Read in ntfs_readpage
2023/05/10 upstream (ToT) 16a8829130ca C [report] KASAN: use-after-free Read in ntfs_read_folio
2024/04/21 upstream (ToT) 977b1ef51866 C Didn't crash
Last patch testing requests (10)
Created Duration User Patch Repo Result
2026/02/06 06:32 18m retest repro linux-5.15.y report log
2026/01/06 07:48 13m retest repro linux-5.15.y report log
2025/12/21 11:56 9m retest repro linux-5.15.y report log
2025/12/21 11:56 9m retest repro linux-5.15.y report log
2025/11/28 04:50 13m retest repro linux-5.15.y report log
2025/10/27 00:03 10m retest repro linux-5.15.y error
2025/10/11 23:32 9m retest repro linux-5.15.y report log
2025/10/11 23:32 9m retest repro linux-5.15.y report log
2025/09/18 17:54 11m retest repro linux-5.15.y report log
2025/08/17 12:17 10m retest repro linux-5.15.y report log
Fix bisection attempts (3)
Created Duration User Patch Repo Result
2024/04/21 21:10 5h43m fix candidate upstream OK (1) job log
2023/05/31 07:05 0m bisect fix linux-5.15.y error job log
2023/04/17 08:03 53m bisect fix linux-5.15.y OK (0) job log log

Sample crash report:
loop0: detected capacity change from 0 to 4096
ntfs: (device loop0): parse_options(): Option utf8 is no longer supported, using option nls=utf8. Please use option nls=utf8 in the future and make sure utf8 is compiled either as a module or into the kernel.
ntfs: volume version 3.1.
==================================================================
BUG: KASAN: use-after-free in ntfs_readpage+0x85a/0x2260 fs/ntfs/aops.c:488
Read of size 10 at addr ffff8880695ec170 by task syz.0.17/4327

CPU: 1 PID: 4327 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x235/0x290 mm/kasan/generic.c:189
 memcpy+0x25/0x60 mm/kasan/shadow.c:65
 ntfs_readpage+0x85a/0x2260 fs/ntfs/aops.c:488
 read_pages+0x61f/0x930 mm/readahead.c:145
 page_cache_ra_unbounded+0x838/0x940 mm/readahead.c:239
 page_cache_sync_readahead include/linux/pagemap.h:833 [inline]
 filemap_get_pages mm/filemap.c:2551 [inline]
 filemap_read+0x5de/0x2540 mm/filemap.c:2634
 __kernel_read+0x517/0x960 fs/read_write.c:443
 integrity_kernel_read+0x86/0xd0 security/integrity/iint.c:228
 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:485 [inline]
 ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline]
 ima_calc_file_hash+0x931/0x1920 security/integrity/ima/ima_crypto.c:573
 ima_collect_measurement+0x337/0x7c0 security/integrity/ima/ima_api.c:255
 process_measurement+0x113a/0x1ba0 security/integrity/ima/ima_main.c:351
 ima_file_check+0xc7/0x110 security/integrity/ima/ima_main.c:533
 do_open fs/namei.c:3618 [inline]
 path_openat+0x27a8/0x2fa0 fs/namei.c:3750
 do_filp_open+0x1e2/0x410 fs/namei.c:3777
 do_sys_openat2+0x150/0x4b0 fs/open.c:1255
 do_sys_open fs/open.c:1271 [inline]
 __do_sys_openat fs/open.c:1287 [inline]
 __se_sys_openat fs/open.c:1282 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1282
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f13b67cf799
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:00007fff2b287e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f13b6a48fa0 RCX: 00007f13b67cf799
RDX: 0000000000141842 RSI: 0000200000000100 RDI: ffffffffffffff9c
RBP: 00007f13b6865bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f13b6a48fac R14: 00007f13b6a48fa0 R15: 00007f13b6a48fa0
 </TASK>

The buggy address belongs to the page:
page:ffffea0001a57b00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x695ec
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001a57a88 ffffea0001a8d508 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 0x1100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 4313, ts 82315882921, free_ts 82318655102
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_pages_vma+0x393/0x7c0 mm/mempolicy.c:2146
 do_anonymous_page mm/memory.c:3838 [inline]
 handle_pte_fault mm/memory.c:4648 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x23be/0x4410 mm/memory.c:4883
 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1355
 handle_page_fault arch/x86/mm/fault.c:1443 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496
 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+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page_list+0x119/0x820 mm/page_alloc.c:3433
 release_pages+0x186c/0x1be0 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+0x176/0x300 mm/mmu_gather.c:338
 exit_mmap+0x3d0/0x640 mm/mmap.c:3218
 __mmput+0x115/0x3b0 kernel/fork.c:1127
 exit_mm+0x588/0x6e0 kernel/exit.c:550
 do_exit+0x5a9/0x20c0 kernel/exit.c:870
 do_group_exit+0x12e/0x300 kernel/exit.c:997
 __do_sys_exit_group kernel/exit.c:1008 [inline]
 __se_sys_exit_group kernel/exit.c:1006 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff8880695ec000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880695ec080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880695ec100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                             ^
 ffff8880695ec180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880695ec200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/07 10:00 linux-5.15.y 91d48252ad4b 5cb44a80 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_readpage
2026/02/22 04:09 linux-5.15.y 3330a8d33e08 6e7b5511 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_readpage
2026/02/22 02:18 linux-5.15.y 3330a8d33e08 6e7b5511 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_readpage
2026/02/21 22:18 linux-5.15.y 3330a8d33e08 6e7b5511 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_readpage
2023/12/30 08:56 linux-5.15.y d93fa2c78854 fb427a07 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_readpage
2023/04/30 08:48 linux-5.15.y f48aeeaaa64c 62df2017 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_readpage
2025/06/15 19:09 linux-5.15.y 1c700860e8bc 5f4b362d .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in ntfs_readpage
2023/03/18 08:02 linux-5.15.y 8020ae3c051d 7939252e .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in ntfs_readpage
2026/02/28 17:42 linux-5.15.y 3330a8d33e08 43249bac .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_readpage
2023/12/29 04:58 linux-5.15.y d93fa2c78854 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_readpage
* Struck through repros no longer work on HEAD.