syzbot


KASAN: use-after-free Write in list_sort

Status: upstream: reported C repro on 2023/01/18 00:18
Subsystems: xfs
[Documentation on labels]
Reported-by: syzbot+f632f1268ced221d14f2@syzkaller.appspotmail.com
First crash: 523d, last: 488d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in list_sort xfs 1 396d 392d 0/27 auto-obsoleted due to no activity on 2023/08/23 01:25
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2023/02/22 00:24 30m bisect fix linux-4.14.y job log (0) log

Sample crash report:
syz-executor303 (13908): drop_caches: 2
syz-executor303 (13879): drop_caches: 2
syz-executor303 (13868): drop_caches: 2
XFS (loop5): Unmounting Filesystem
==================================================================
BUG: KASAN: use-after-free in list_sort.part.0+0x693/0x6d0 lib/list_sort.c:117
Write of size 8 at addr ffff8880b4aad148 by task syz-executor303/13894

CPU: 1 PID: 13894 Comm: syz-executor303 Not tainted 4.14.303-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_store8_noabort+0x68/0x70 mm/kasan/report.c:435
 list_sort.part.0+0x693/0x6d0 lib/list_sort.c:117
 list_sort+0x46/0x60 lib/list_sort.c:112
 xfs_buf_delwri_submit_buffers+0x96/0x9c0 fs/xfs/xfs_buf.c:1992
 xfs_buf_delwri_submit+0x76/0x240 fs/xfs/xfs_buf.c:2075
 xfs_qm_quotacheck+0x2a7/0x790 fs/xfs/xfs_qm.c:1367
 xfs_qm_mount_quotas+0xe9/0x570 fs/xfs/xfs_qm.c:1457
 xfs_mountfs+0x18be/0x1f40 fs/xfs/xfs_mount.c:979
 xfs_fs_fill_super+0xb7a/0x1380 fs/xfs/xfs_super.c:1688
 mount_bdev+0x2b3/0x360 fs/super.c:1134
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2572 [inline]
 do_mount+0xe65/0x2a30 fs/namespace.c:2905
 SYSC_mount fs/namespace.c:3121 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3098
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3
RIP: 0033:0x7f2ba5c6ff8a
RSP: 002b:00007ffc14f50a28 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00646975756f6e2c RCX: 00007f2ba5c6ff8a
RDX: 000000002000bb00 RSI: 0000000020000040 RDI: 00007ffc14f50a40
RBP: 00007ffc14f50a40 R08: 00007ffc14f50a80 R09: 000000000000bae7
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000004
R13: 0000555556f452c0 R14: 0000000000000000 R15: 00007ffc14f50a80

Allocated by task 13894:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 kmem_cache_alloc+0x124/0x3c0 mm/slab.c:3552
 kmem_zone_alloc+0x7f/0x180 fs/xfs/kmem.c:106
 kmem_zone_zalloc fs/xfs/kmem.h:131 [inline]
 _xfs_buf_alloc+0x32/0xcf0 fs/xfs/xfs_buf.c:248
 xfs_buf_get_map+0x436/0x5f0 fs/xfs/xfs_buf.c:695
 xfs_trans_get_buf_map+0x277/0x710 fs/xfs/xfs_trans_buf.c:170
 xfs_trans_get_buf fs/xfs/xfs_trans.h:179 [inline]
 xfs_qm_dqalloc+0x5e6/0xa20 fs/xfs/xfs_dquot.c:354
 xfs_qm_dqtobp+0x926/0xcf0 fs/xfs/xfs_dquot.c:518
 xfs_qm_dqread+0x3a3/0xe50 fs/xfs/xfs_dquot.c:629
 xfs_qm_dqget+0x4f4/0x19a0 fs/xfs/xfs_dquot.c:837
 xfs_qm_quotacheck_dqadjust+0x96/0x5c0 fs/xfs/xfs_qm.c:1077
 xfs_qm_dqusage_adjust+0x428/0xc20 fs/xfs/xfs_qm.c:1192
 xfs_bulkstat_ag_ichunk fs/xfs/xfs_itable.c:313 [inline]
 xfs_bulkstat+0x72a/0xf60 fs/xfs/xfs_itable.c:498
 xfs_qm_quotacheck+0x223/0x790 fs/xfs/xfs_qm.c:1338
 xfs_qm_mount_quotas+0xe9/0x570 fs/xfs/xfs_qm.c:1457
 xfs_mountfs+0x18be/0x1f40 fs/xfs/xfs_mount.c:979
 xfs_fs_fill_super+0xb7a/0x1380 fs/xfs/xfs_super.c:1688
 mount_bdev+0x2b3/0x360 fs/super.c:1134
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2572 [inline]
 do_mount+0xe65/0x2a30 fs/namespace.c:2905
 SYSC_mount fs/namespace.c:3121 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3098
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3

Freed by task 13868:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kmem_cache_free+0x7c/0x2b0 mm/slab.c:3758
 xfs_buf_rele+0x810/0x12a0 fs/xfs/xfs_buf.c:1074
 xfs_buftarg_shrink_scan+0x18a/0x270 fs/xfs/xfs_buf.c:1769
 do_shrink_slab mm/vmscan.c:401 [inline]
 shrink_slab+0x535/0xb60 mm/vmscan.c:504
 drop_slab_node+0x2b/0x60 mm/vmscan.c:531
 drop_slab+0x39/0x70 mm/vmscan.c:542
 drop_caches_sysctl_handler+0xc9/0xe0 fs/drop_caches.c:65
 proc_sys_call_handler.isra.0+0x1ba/0x340 fs/proc/proc_sysctl.c:598
 __vfs_write+0xe4/0x630 fs/read_write.c:480
 __kernel_write+0xf5/0x330 fs/read_write.c:501
 write_pipe_buf+0x143/0x1c0 fs/splice.c:797
 splice_from_pipe_feed fs/splice.c:502 [inline]
 __splice_from_pipe+0x326/0x7a0 fs/splice.c:626
 splice_from_pipe fs/splice.c:661 [inline]
 default_file_splice_write+0xc5/0x150 fs/splice.c:809
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x115/0x160 fs/splice.c:1018
 splice_direct_to_actor+0x27c/0x730 fs/splice.c:973
 do_splice_direct+0x164/0x210 fs/splice.c:1061
 do_sendfile+0x47f/0xb30 fs/read_write.c:1441
 SYSC_sendfile64 fs/read_write.c:1496 [inline]
 SyS_sendfile64+0x9b/0x110 fs/read_write.c:1488
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3

The buggy address belongs to the object at ffff8880b4aad040
 which belongs to the cache xfs_buf of size 584
The buggy address is located 264 bytes inside of
 584-byte region [ffff8880b4aad040, ffff8880b4aad288)
The buggy address belongs to the page:
page:ffffea0002d2ab40 count:1 mapcount:0 mapping:ffff8880b4aad040 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffff8880b4aad040 0000000000000000 0000000100000005
raw: ffffea000273cde0 ffffea000286bfa0 ffff8880b0c03000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880b4aad000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff8880b4aad080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880b4aad100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff8880b4aad180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880b4aad200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
syz-executor303 (13908): drop_caches: 2
XFS (loop0): Unmounting Filesystem
XFS (loop1): Unmounting Filesystem

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/01/22 22:35 linux-4.14.y 97205fccccdc cc0f9968 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-4-14 KASAN: use-after-free Write in list_sort
2023/01/18 00:18 linux-4.14.y c4215ee4771b 42660d9e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 KASAN: use-after-free Write in list_sort
* Struck through repros no longer work on HEAD.