syzbot


KASAN: slab-out-of-bounds Read in xlog_pack_data

Status: upstream: reported C repro on 2023/06/14 05:02
Bug presence: origin:upstream
Labels: missing-backport
[Documentation on labels]
Reported-by: syzbot+904ffc7f25c759741787@syzkaller.appspotmail.com
First crash: 376d, last: 331d
Bug presence (3)
Date Name Commit Repro Result
2023/07/29 linux-6.1.y (ToT) d2a6dc4eaf6d C [report] KASAN: slab-out-of-bounds Read in xlog_pack_data
2023/06/14 upstream (ToT) b6dad5178cea C [report] KASAN: slab-out-of-bounds Read in xlog_pack_data
2023/07/29 upstream (ToT) ffabf7c73176 C Didn't crash
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-out-of-bounds Read in xlog_pack_data xfs C error done 4 376d 372d 23/27 fixed on 2023/10/12 12:48
linux-5.15 KASAN: slab-out-of-bounds Read in xlog_pack_data origin:upstream missing-backport C error 1 330d 376d 0/3 upstream: reported C repro on 2023/06/14 08:07
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2023/09/07 09:01 2h00m fix candidate upstream job log (0)

Sample crash report:
XFS (loop0): Torn write (CRC failure) detected at log block 0x10. Truncating head block from 0x20.
XFS (loop0): Ending clean mount
XFS (loop0): Unmounting Filesystem
==================================================================
BUG: KASAN: slab-out-of-bounds in xlog_pack_data+0x2c8/0x444 fs/xfs/xfs_log.c:1795
Read of size 4 at addr ffff0000d71a4e00 by task syz-executor159/4223

CPU: 1 PID: 4223 Comm: syz-executor159 Not tainted 6.1.33-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x174/0x4c0 mm/kasan/report.c:395
 kasan_report+0xd4/0x130 mm/kasan/report.c:495
 __asan_report_load4_noabort+0x2c/0x38 mm/kasan/report_generic.c:350
 xlog_pack_data+0x2c8/0x444 fs/xfs/xfs_log.c:1795
 xlog_sync+0x3b8/0x11fc fs/xfs/xfs_log.c:2066
 xlog_state_release_iclog+0x4bc/0xa78 fs/xfs/xfs_log.c:619
 xlog_force_iclog fs/xfs/xfs_log.c:886 [inline]
 xlog_force_and_check_iclog fs/xfs/xfs_log.c:3156 [inline]
 xlog_force_lsn+0x69c/0x81c fs/xfs/xfs_log.c:3328
 xfs_log_force_seq+0x218/0x50c fs/xfs/xfs_log.c:3393
 __xfs_trans_commit+0xa1c/0x10a0 fs/xfs/xfs_trans.c:1014
 xfs_trans_commit+0x24/0x34 fs/xfs/xfs_trans.c:1049
 xfs_sync_sb+0x144/0x1ac fs/xfs/libxfs/xfs_sb.c:1012
 xfs_log_cover fs/xfs/xfs_log.c:1273 [inline]
 xfs_log_quiesce+0x57c/0x844 fs/xfs/xfs_log.c:1090
 xfs_log_clean+0xb0/0xde8 fs/xfs/xfs_log.c:1097
 xfs_log_unmount+0x30/0xbc fs/xfs/xfs_log.c:1112
 xfs_unmountfs+0x130/0x1d0 fs/xfs/xfs_mount.c:1081
 xfs_fs_put_super+0x78/0x260 fs/xfs/xfs_super.c:1115
 generic_shutdown_super+0x130/0x328 fs/super.c:501
 kill_block_super+0x70/0xdc fs/super.c:1450
 deactivate_locked_super+0xac/0x124 fs/super.c:332
 deactivate_super+0xf0/0x110 fs/super.c:363
 cleanup_mnt+0x394/0x41c fs/namespace.c:1186
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1193
 task_work_run+0x240/0x2f0 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x554/0x1a88 kernel/exit.c:869
 do_group_exit+0x194/0x22c kernel/exit.c:1019
 __do_sys_exit_group kernel/exit.c:1030 [inline]
 __se_sys_exit_group kernel/exit.c:1028 [inline]
 __wake_up_parent+0x0/0x60 kernel/exit.c:1028
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

The buggy address belongs to the physical page:
page:00000000a77b331a refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x117180
head:00000000a77b331a order:6 compound_mapcount:0 compound_pincount:0
flags: 0x5ffc00000010000(head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000d71a4d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000d71a4d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000d71a4e00: 01 fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
                   ^
 ffff0000d71a4e80: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
 ffff0000d71a4f00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/06/14 05:02 linux-6.1.y 2f3918bc53fb d2ee9228 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in xlog_pack_data
* Struck through repros no longer work on HEAD.