syzbot


UBSAN: array-index-out-of-bounds in decompress_lznt

Status: upstream: reported C repro on 2024/05/14 16:19
Subsystems: ntfs3
[Documentation on labels]
Reported-by: syzbot+39b2fb0f2638669008ec@syzkaller.appspotmail.com
First crash: 42d, last: 28d
Cause bisection: introduced by (bisect log) :
commit d68968440b1a75dee05cfac7f368f1aa139e1911
Author: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Date: Mon Jan 29 07:30:09 2024 +0000

  fs/ntfs3: Update inode->i_size after success write into compressed file

Crash: UBSAN: array-index-out-of-bounds in decompress_lznt (log)
Repro: C syz .config
  
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] ntfs3: check if more than chunk-size bytes are written 1 (2) 2024/05/15 12:59
[syzbot] [ntfs3?] UBSAN: array-index-out-of-bounds in decompress_lznt 0 (1) 2024/05/14 16:19
Last patch testing requests (2)
Created Duration User Patch Repo Result
2024/05/25 02:23 11m retest repro upstream report log
2024/05/15 12:40 17m andrewjballance@gmail.com patch upstream OK log

Sample crash report:
------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/ntfs3/lznt.c:240:16
index 9 is out of range for type 'const size_t[9]' (aka 'const unsigned long[9]')
CPU: 1 PID: 5072 Comm: syz-executor335 Not tainted 6.9.0-rc7-syzkaller-00136-gf4345f05c0df #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_out_of_bounds+0x121/0x150 lib/ubsan.c:429
 decompress_chunk fs/ntfs3/lznt.c:240 [inline]
 decompress_lznt+0x229/0xd50 fs/ntfs3/lznt.c:387
 ni_read_frame+0x1633/0x1c50 fs/ntfs3/frecord.c:2684
 ni_readpage_cmpr+0x38b/0xa60 fs/ntfs3/frecord.c:2143
 ntfs_read_folio+0x19e/0x210 fs/ntfs3/inode.c:725
 filemap_read_folio+0x1a0/0x790 mm/filemap.c:2331
 filemap_update_page mm/filemap.c:2415 [inline]
 filemap_get_pages+0x15a9/0x2090 mm/filemap.c:2529
 filemap_read+0x457/0xfa0 mm/filemap.c:2601
 __kernel_read+0x5c8/0xab0 fs/read_write.c:434
 integrity_kernel_read+0xb0/0x100 security/integrity/iint.c:28
 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+0xadb/0x1b30 security/integrity/ima/ima_crypto.c:573
 ima_collect_measurement+0x535/0xa90 security/integrity/ima/ima_api.c:291
 process_measurement+0x13ac/0x1f60 security/integrity/ima/ima_main.c:359
 ima_file_check+0xf2/0x170 security/integrity/ima/ima_main.c:559
 security_file_post_open+0x6d/0xa0 security/security.c:2981
 do_open fs/namei.c:3644 [inline]
 path_openat+0x28b7/0x3240 fs/namei.c:3799
 do_filp_open+0x235/0x490 fs/namei.c:3826
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_open fs/open.c:1429 [inline]
 __se_sys_open fs/open.c:1425 [inline]
 __x64_sys_open+0x225/0x270 fs/open.c:1425
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbd0c2059b9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffa3c72cd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fffa3c72ea8 RCX: 00007fbd0c2059b9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180
RBP: 00007fbd0c298610 R08: 00007fffa3c72ea8 R09: 00007fffa3c72ea8
R10: 00007fffa3c72ea8 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fffa3c72e98 R14: 0000000000000001 R15: 0000000000000001
 </TASK>
---[ end trace ]---

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/11 01:53 upstream f4345f05c0df f7c35481 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-upstream-fs UBSAN: array-index-out-of-bounds in decompress_lznt
2024/05/11 01:31 upstream f4345f05c0df f7c35481 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs UBSAN: array-index-out-of-bounds in decompress_lznt
* Struck through repros no longer work on HEAD.