syzbot


KASAN: null-ptr-deref Write in xfs_filestream_select_ag

Status: upstream: reported C repro on 2023/03/22 08:34
Labels: xfs (incorrect?)
Reported-by: syzbot+87466712bb342796810a@syzkaller.appspotmail.com
First crash: 78d, last: 1d13h

Cause bisection: introduced by (bisect log) :
commit 3e43877a9dac13771ac722462c87bea0bdc50759
Author: Dave Chinner <dchinner@redhat.com>
Date: Sun Feb 12 22:14:55 2023 +0000

  xfs: remove xfs_filestream_select_ag() longest extent check

Crash: general protection fault in xfs_filestream_select_ag (log)
Repro: C syz .config
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly xfs report (May 2023) 1 (2) 2023/05/05 13:59
[syzbot] [xfs?] KASAN: null-ptr-deref Write in xfs_filestream_select_ag 0 (1) 2023/03/22 08:34

Sample crash report:
XFS (loop0): metadata I/O error in "xfs_read_agf+0x27c/0x500" at daddr 0x1 len 1 error 117
XFS (loop0): page discard on page ffffea0001cbc2c0, inode 0x2a, pos 0.
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: null-ptr-deref in atomic_inc include/linux/atomic/atomic-instrumented.h:190 [inline]
BUG: KASAN: null-ptr-deref in xfs_filestream_pick_ag fs/xfs/xfs_filestream.c:156 [inline]
BUG: KASAN: null-ptr-deref in xfs_filestream_create_association fs/xfs/xfs_filestream.c:301 [inline]
BUG: KASAN: null-ptr-deref in xfs_filestream_select_ag+0x188b/0x1cc0 fs/xfs/xfs_filestream.c:372
Write of size 4 at addr 00000000000001c0 by task kworker/u4:4/66

CPU: 1 PID: 66 Comm: kworker/u4:4 Not tainted 6.4.0-rc5-syzkaller-00016-ga4d7d7011219 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 print_report mm/kasan/report.c:465 [inline]
 kasan_report+0xec/0x130 mm/kasan/report.c:572
 check_region_inline mm/kasan/generic.c:181 [inline]
 kasan_check_range+0x141/0x190 mm/kasan/generic.c:187
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_inc include/linux/atomic/atomic-instrumented.h:190 [inline]
 xfs_filestream_pick_ag fs/xfs/xfs_filestream.c:156 [inline]
 xfs_filestream_create_association fs/xfs/xfs_filestream.c:301 [inline]
 xfs_filestream_select_ag+0x188b/0x1cc0 fs/xfs/xfs_filestream.c:372
 xfs_bmap_btalloc_filestreams fs/xfs/libxfs/xfs_bmap.c:3593 [inline]
 xfs_bmap_btalloc+0xe58/0x1c10 fs/xfs/libxfs/xfs_bmap.c:3707
 xfs_bmap_alloc_userdata fs/xfs/libxfs/xfs_bmap.c:4081 [inline]
 xfs_bmapi_allocate+0x597/0x1200 fs/xfs/libxfs/xfs_bmap.c:4124
 xfs_bmapi_convert_delalloc+0x3e7/0xd20 fs/xfs/libxfs/xfs_bmap.c:4589
 xfs_convert_blocks fs/xfs/xfs_aops.c:266 [inline]
 xfs_map_blocks+0x74c/0xf80 fs/xfs/xfs_aops.c:389
 iomap_writepage_map fs/iomap/buffered-io.c:1634 [inline]
 iomap_do_writepage+0xa1e/0x23d0 fs/iomap/buffered-io.c:1796
 write_cache_pages+0x4a2/0xd30 mm/page-writeback.c:2473
 iomap_writepages+0x4f/0xb0 fs/iomap/buffered-io.c:1813
 xfs_vm_writepages+0x138/0x1c0 fs/xfs/xfs_aops.c:513
 do_writepages+0x1a8/0x640 mm/page-writeback.c:2551
 __writeback_single_inode+0x121/0xdb0 fs/fs-writeback.c:1603
 writeback_sb_inodes+0x54d/0xe70 fs/fs-writeback.c:1894
 wb_writeback+0x294/0xa50 fs/fs-writeback.c:2068
 wb_do_writeback fs/fs-writeback.c:2211 [inline]
 wb_workfn+0x2a5/0xfc0 fs/fs-writeback.c:2251
 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405
 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552
 kthread+0x344/0x440 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
==================================================================

Crashes (18):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Manager Title
2023/06/07 03:19 upstream a4d7d7011219 a4ae4f42 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kasan-gce-root KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/03/21 19:13 upstream 17214b70a159 8b4eb097 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/05/14 09:01 upstream bb7c241fae62 2b9ba477 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/05/13 00:22 upstream cc3c44c9fda2 ecca8a24 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/05/12 10:25 upstream 105131df9c3b adb9a3cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/05/11 02:02 upstream d295b66a7b66 14b12a99 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/05/10 03:41 upstream 1dc3731daf1f 30aa2a7e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/05/02 20:16 upstream 865fdb08197e 48e0a81d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/04/29 13:36 upstream 89d77f71f493 62df2017 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/04/21 23:33 upstream 2af3e53a4dc0 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/04/16 09:05 upstream a7a55e27ad72 ec410564 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/04/15 03:38 upstream 95abc817ab3a ec410564 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/04/13 08:18 upstream 0bcc40255504 82d5e53e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/04/06 19:14 upstream 99ddf2254feb 08707520 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/04/06 01:54 upstream 99ddf2254feb 8b834965 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/03/31 15:34 upstream 62bad54b26db f325deb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/03/29 12:43 upstream fcd476ea6a88 f325deb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
2023/03/21 18:34 upstream 17214b70a159 8b4eb097 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: null-ptr-deref Write in xfs_filestream_select_ag
* Struck through repros no longer work on HEAD.