syzbot


KASAN: use-after-free Read in ocfs2_search_extent_list

Status: upstream: reported C repro on 2024/12/09 23:04
Subsystems: ocfs2
[Documentation on labels]
Reported-by: syzbot+2313dda4dc4885c93578@syzkaller.appspotmail.com
First crash: 15d, last: 10d
Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: KASAN: use-after-free Read in ocfs2_search_extent_list (log)
Repro: C syz .config
  
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] ocfs2: Add a sanity check for corrupted file system. 1 (1) 2024/12/10 13:08
[syzbot] [ocfs2?] KASAN: use-after-free Read in ocfs2_search_extent_list 2 (6) 2024/12/10 11:47
Last patch testing requests (3)
Created Duration User Patch Repo Result
2024/12/10 11:27 19m dmantipov@yandex.ru patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 7cb1b466315004af98f6ba6c2546bb713ca3c237 OK log
2024/12/10 11:24 19m sunjunchao2870@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 5076001689e4 OK log
2024/12/10 11:07 20m eadavis@qq.com https://github.com/ea1davis/linux ocfs2/syz OK log

Sample crash report:
WARNING: The mand mount option has been deprecated and
         and is ignored by this kernel. Remove the mand
         option from the mount to silence this warning.
=======================================================
JBD2: Ignoring recovery information on journal
==================================================================
BUG: KASAN: use-after-free in ocfs2_search_extent_list+0x155/0x200 fs/ocfs2/alloc.c:776
Read of size 4 at addr ffff88804e0f7000 by task syz-executor327/5820

CPU: 0 UID: 0 PID: 5820 Comm: syz-executor327 Not tainted 6.13.0-rc2-syzkaller-00031-gf92f4749861b #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_search_extent_list+0x155/0x200 fs/ocfs2/alloc.c:776
 ocfs2_get_clusters_nocache+0x21a/0xbf0 fs/ocfs2/extent_map.c:438
 ocfs2_get_clusters+0x5bd/0xbd0 fs/ocfs2/extent_map.c:621
 ocfs2_extent_map_get_blocks+0x24c/0x7d0 fs/ocfs2/extent_map.c:668
 ocfs2_bmap+0x2b7/0x780 fs/ocfs2/aops.c:474
 bmap+0xa8/0xe0 fs/inode.c:1997
 jbd2_journal_bmap+0x12d/0x2b0 fs/jbd2/journal.c:926
 do_readahead fs/jbd2/recovery.c:88 [inline]
 jread+0x435/0xc80 fs/jbd2/recovery.c:165
 do_one_pass+0x3cd/0x3aa0 fs/jbd2/recovery.c:646
 jbd2_journal_skip_recovery+0x95/0x240 fs/jbd2/recovery.c:366
 jbd2_journal_wipe+0xc9/0x110 fs/jbd2/journal.c:2517
 ocfs2_journal_wipe+0xab/0x2a0 fs/ocfs2/journal.c:1192
 ocfs2_check_volume fs/ocfs2/super.c:2413 [inline]
 ocfs2_mount_volume+0xb86/0x1940 fs/ocfs2/super.c:1817
 ocfs2_fill_super+0x476e/0x5760 fs/ocfs2/super.c:1084
 mount_bdev+0x20a/0x2d0 fs/super.c:1693
 legacy_get_tree+0xee/0x190 fs/fs_context.c:662
 vfs_get_tree+0x90/0x2b0 fs/super.c:1814
 do_new_mount+0x2be/0xb40 fs/namespace.c:3507
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034
 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: 0033:0x7f71cfdb41aa
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007ffff267f8e8 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffff267f900 RCX: 00007f71cfdb41aa
RDX: 0000000020004440 RSI: 0000000020000040 RDI: 00007ffff267f900
RBP: 0000000000000004 R08: 00007ffff267f940 R09: 0000000000004431
R10: 00000000000008c0 R11: 0000000000000282 R12: 00000000000008c0
R13: 00007ffff267f940 R14: 0000000000000003 R15: 0000000001000000
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4e0f7
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001383e08 ffff8880b8644830 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 14558112771, free_ts 15104107640
 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+0xd2c/0x1000 mm/page_alloc.c:2657
 free_contig_range+0x14c/0x430 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:
 ffff88804e0f6f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88804e0f6f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88804e0f7000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88804e0f7080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804e0f7100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/12/11 04:20 upstream f92f4749861b cfc402b4 .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_extent_list
2024/12/05 23:04 upstream 5076001689e4 1c533826 .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_extent_list
2024/12/05 22:56 upstream 5076001689e4 1c533826 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: use-after-free Read in ocfs2_search_extent_list
* Struck through repros no longer work on HEAD.