syzbot

 sign-in | mailing list | source | docs
🐞 Open [851]
🐞 Fixed [87]
🐞 Invalid [1250]
⬇ Missing Backports [132]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

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: 1103d, last: 6d07h
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 ffff88806a09c170 by task syz.0.19/4310

CPU: 0 PID: 4310 Comm: syz.0.19 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: 0033:0x7f1bdd051799
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:00007ffeb3da19c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f1bdd2cafa0 RCX: 00007f1bdd051799
RDX: 0000000000141842 RSI: 0000200000000100 RDI: ffffffffffffff9c
RBP: 00007f1bdd0e7c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1bdd2cafac R14: 00007f1bdd2cafa0 R15: 00007f1bdd2cafa0
 </TASK>

The buggy address belongs to the page:
page:ffffea0001a82700 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x6a09c
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001a82748 ffffea0001aae348 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 4310, ts 85659647037, free_ts 85685923858
 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
 __page_cache_alloc+0xce/0x440 mm/filemap.c:1022
 do_read_cache_page+0x1da/0x1030 mm/filemap.c:3457
 read_mapping_page include/linux/pagemap.h:515 [inline]
 ntfs_map_page+0x24/0x390 fs/ntfs/aops.h:75
 load_and_init_upcase fs/ntfs/super.c:1678 [inline]
 load_system_files+0x1d47/0x55a0 fs/ntfs/super.c:1810
 ntfs_fill_super+0x19e0/0x2c90 fs/ntfs/super.c:2894
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 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
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
 __pagevec_release+0x6d/0xe0 mm/swap.c:983
 pagevec_release include/linux/pagevec.h:81 [inline]
 truncate_inode_pages_range+0x362/0xfe0 mm/truncate.c:329
 ntfs_evict_big_inode+0x2d/0x4a0 fs/ntfs/inode.c:2251
 evict+0x4c9/0x8d0 fs/inode.c:647
 load_and_init_upcase fs/ntfs/super.c:1693 [inline]
 load_system_files+0x276a/0x55a0 fs/ntfs/super.c:1810
 ntfs_fill_super+0x19e0/0x2c90 fs/ntfs/super.c:2894
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 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:
 ffff88806a09c000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806a09c080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88806a09c100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                             ^
 ffff88806a09c180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806a09c200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/19 06:26 linux-5.15.y 91d48252ad4b 0199f9a1 .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
2026/03/07 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.