syzbot


KASAN: use-after-free Read in ocfs2_search_dirblock

Status: upstream: reported C repro on 2024/08/16 09:49
Subsystems: ocfs2
[Documentation on labels]
Reported-by: syzbot+b9704899e166798d57c9@syzkaller.appspotmail.com
Fix commit: ocfs2: fix directory entry check in ocfs2_search_dirblock()
Patched on: [ci-upstream-linux-next-kasan-gce-root], missing on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 187d, last: 40d
Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: KASAN: slab-out-of-bounds Read in ocfs2_find_entry (log)
Repro: C syz .config
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ocfs2?] KASAN: use-after-free Read in ocfs2_search_dirblock 0 (2) 2024/11/19 16:28
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 KASAN: use-after-free Read in ocfs2_search_dirblock C 7 2d10h 15d 0/3 upstream: reported C repro on 2025/02/04 10:38
linux-6.1 KASAN: use-after-free Read in ocfs2_search_dirblock origin:lts-only C 2 28d 28d 0/3 upstream: reported C repro on 2025/01/21 15:12
Last patch testing requests (7)
Created Duration User Patch Repo Result
2024/11/19 16:28 19m dmantipov@yandex.ru patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 158f238aa69d91ad74e535c73f552bd4b025109c OK log
2024/11/08 07:51 13m retest repro upstream report log
2024/11/08 07:51 13m retest repro upstream report log
2024/11/08 07:51 13m retest repro upstream report log
2024/08/30 05:29 18m retest repro upstream report log
2024/08/30 05:29 18m retest repro upstream report log
2024/08/30 05:29 18m retest repro upstream report log

Sample crash report:
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
==================================================================
BUG: KASAN: use-after-free in ocfs2_match fs/ocfs2/dir.c:334 [inline]
BUG: KASAN: use-after-free in ocfs2_search_dirblock+0x26b/0x820 fs/ocfs2/dir.c:367
Read of size 1 at addr ffff8880710858cb by task syz-executor292/5841

CPU: 0 UID: 0 PID: 5841 Comm: syz-executor292 Not tainted 6.12.0-syzkaller-10740-g509f806f7f70 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:489
 kasan_report+0x143/0x180 mm/kasan/report.c:602
 ocfs2_match fs/ocfs2/dir.c:334 [inline]
 ocfs2_search_dirblock+0x26b/0x820 fs/ocfs2/dir.c:367
 ocfs2_find_entry_id fs/ocfs2/dir.c:414 [inline]
 ocfs2_find_entry+0x1169/0x2730 fs/ocfs2/dir.c:1078
 ocfs2_find_files_on_disk+0xff/0x360 fs/ocfs2/dir.c:1981
 ocfs2_lookup_ino_from_name+0xb1/0x1e0 fs/ocfs2/dir.c:2003
 ocfs2_lookup+0x292/0xa30 fs/ocfs2/namei.c:122
 lookup_open fs/namei.c:3627 [inline]
 open_last_lookups fs/namei.c:3748 [inline]
 path_openat+0x11a7/0x3590 fs/namei.c:3984
 do_filp_open+0x27f/0x4e0 fs/namei.c:4014
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402
 do_sys_open fs/open.c:1417 [inline]
 __do_sys_open fs/open.c:1425 [inline]
 __se_sys_open fs/open.c:1421 [inline]
 __x64_sys_open+0x225/0x270 fs/open.c:1421
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f45aff47a59
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 18 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:00007f45afefe218 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f45affd36a8 RCX: 00007f45aff47a59
RDX: 0000000000000000 RSI: 0000000400141042 RDI: 0000000020000080
RBP: 00007f45affd36a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f45aff9c0c0
R13: 0000000400141042 R14: 00007f45aff9c200 R15: 0031656c69662f2e
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x71085
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001c42188 ffffea0001c42108 0000000000000000
raw: 0000000000000000 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 0x8(__GFP_MOVABLE), pid 1, tgid 1 (swapper/0), ts 16694661071, free_ts 17832813418
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556
 split_free_pages mm/page_alloc.c:6360 [inline]
 alloc_contig_range_noprof+0x821/0xe00 mm/page_alloc.c:6487
 __alloc_contig_pages mm/page_alloc.c:6516 [inline]
 alloc_contig_pages_noprof+0x4b3/0x5c0 mm/page_alloc.c:6596
 debug_vm_pgtable_alloc_huge_page+0xaf/0x100 mm/debug_vm_pgtable.c:1084
 init_args+0x83b/0xb20 mm/debug_vm_pgtable.c:1266
 debug_vm_pgtable+0xe0/0x550 mm/debug_vm_pgtable.c:1304
 do_one_initcall+0x248/0x870 init/main.c:1266
 do_initcall_level+0x157/0x210 init/main.c:1328
 do_initcalls+0x3f/0x80 init/main.c:1344
 kernel_init_freeable+0x435/0x5d0 init/main.c:1577
 kernel_init+0x1d/0x2b0 init/main.c:1466
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0xde3/0x1130 mm/page_alloc.c:2657
 free_contig_range+0x152/0x550 mm/page_alloc.c:6630
 destroy_args+0x92/0x910 mm/debug_vm_pgtable.c:1017
 debug_vm_pgtable+0x4be/0x550 mm/debug_vm_pgtable.c:1397
 do_one_initcall+0x248/0x870 init/main.c:1266
 do_initcall_level+0x157/0x210 init/main.c:1328
 do_initcalls+0x3f/0x80 init/main.c:1344
 kernel_init_freeable+0x435/0x5d0 init/main.c:1577
 kernel_init+0x1d/0x2b0 init/main.c:1466
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff888071085780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888071085800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888071085880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff888071085900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888071085980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (14):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/30 02:20 upstream 509f806f7f70 68914665 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs KASAN: use-after-free Read in ocfs2_search_dirblock
2024/08/16 03:58 upstream d7a5aa4b3c00 e4bacdaf .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root KASAN: use-after-free Read in ocfs2_search_dirblock
2024/11/28 15:16 linux-next f486c8aa16b8 5df23865 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-linux-next-kasan-gce-root KASAN: use-after-free Read in ocfs2_search_dirblock
2024/08/16 05:29 upstream d7a5aa4b3c00 e4bacdaf .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in ocfs2_search_dirblock
2024/08/16 04:45 upstream d7a5aa4b3c00 e4bacdaf .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in ocfs2_search_dirblock
2025/01/09 20:06 upstream eea6e4b4dfb8 9220929f .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: use-after-free Read in ocfs2_search_dirblock
2024/12/01 03:52 upstream d8b78066f4c9 68914665 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: use-after-free Read in ocfs2_search_dirblock
2024/10/04 12:33 upstream 3840cbe24cf0 d7906eff .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: use-after-free Read in ocfs2_search_dirblock
2024/08/16 03:04 upstream d7a5aa4b3c00 e4bacdaf .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: use-after-free Read in ocfs2_search_dirblock
2024/11/28 14:27 linux-next f486c8aa16b8 5df23865 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: use-after-free Read in ocfs2_search_dirblock
2025/01/03 01:49 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 573067a5a685 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: use-after-free Read in ocfs2_search_dirblock
2024/12/28 03:37 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 573067a5a685 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: use-after-free Read in ocfs2_search_dirblock
2024/12/22 05:10 upstream 48f506ad0b68 d7f584ee .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in ocfs2_search_dirblock
2024/12/20 19:49 upstream 8faabc041a00 49cfeac8 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in ocfs2_search_dirblock
* Struck through repros no longer work on HEAD.