syzbot


general protection fault in __ext4_journal_get_write_access

Status: fixed on 2022/11/15 22:34
Reported-by: syzbot+@syzkaller.appspotmail.com
Fix commit: 384d87ef2c95 block: Do not discard buffers under a mounted filesystem
First crash: 859d, last: 810d

Cause bisection: introduced by (bisect log) :
commit 89dd9a8c27f841704b527810f9180f06c351b89b
Author: Lee Jones <lee.jones@linaro.org>
Date: Mon Jul 6 13:33:12 2020 +0000

  usb: gadget: legacy: printer: Remove unused variable 'driver_desc'

Crash: WARNING: ODEBUG bug in netdev_run_todo (log)
Repro: C syz .config

Fix bisection: fixed by (bisect log) :
commit 384d87ef2c954fc58e6c5fd8253e4a1984f5fe02
Author: Jan Kara <jack@suse.cz>
Date: Fri Sep 4 08:58:52 2020 +0000

  block: Do not discard buffers under a mounted filesystem

Last patch testing requests:
Created Duration User Patch Repo Result
2022/09/25 21:30 18m retest repro upstream OK log
2022/09/23 10:30 18m retest repro upstream OK log
2022/09/21 12:29 19m retest repro upstream OK log
2022/09/21 09:29 9m retest repro upstream error

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 1 PID: 3564 Comm: kworker/u4:5 Not tainted 5.9.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:__ext4_journal_get_write_access+0x7c/0x440 fs/ext4/ext4_jbd2.c:227
Code: 54 ff 49 8d 5f 30 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 f2 09 b8 ff 48 8b 1b 48 83 c3 10 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 d5 09 b8 ff 4c 8b 2b 4d 85 ed 4c
RSP: 0018:ffffc900060e7050 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 0000000000000010 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffffff896fe520 RDI: 0000000000000286
RBP: ffffc900060e70c0 R08: dffffc0000000000 R09: fffffbfff135f926
R10: fffffbfff135f926 R11: 0000000000000000 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880a4d180e8
FS:  0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffedb7192c0 CR3: 000000009ba49000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ext4_mb_mark_diskspace_used+0x1f1/0x1690 fs/ext4/mballoc.c:3229
 ext4_mb_new_blocks+0x807/0x1710 fs/ext4/mballoc.c:4938
 ext4_ext_map_blocks+0x2ace/0x6d20 fs/ext4/extents.c:4238
 ext4_map_blocks+0x8b5/0x19d0 fs/ext4/inode.c:625
 mpage_map_one_extent fs/ext4/inode.c:2376 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2429 [inline]
 ext4_writepages+0x1657/0x3b00 fs/ext4/inode.c:2781
 do_writepages+0xda/0x1f0 mm/page-writeback.c:2352
 __writeback_single_inode+0xcc/0x640 fs/fs-writeback.c:1461
 writeback_sb_inodes+0x8f3/0x17f0 fs/fs-writeback.c:1721
 __writeback_inodes_wb fs/fs-writeback.c:1790 [inline]
 wb_writeback+0x483/0x8f0 fs/fs-writeback.c:1896
 wb_check_old_data_flush fs/fs-writeback.c:1998 [inline]
 wb_do_writeback fs/fs-writeback.c:2051 [inline]
 wb_workfn+0x963/0x11e0 fs/fs-writeback.c:2080
 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Modules linked in:
---[ end trace f27b229b43e07582 ]---
RIP: 0010:__ext4_journal_get_write_access+0x7c/0x440 fs/ext4/ext4_jbd2.c:227
Code: 54 ff 49 8d 5f 30 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 f2 09 b8 ff 48 8b 1b 48 83 c3 10 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 d5 09 b8 ff 4c 8b 2b 4d 85 ed 4c
RSP: 0018:ffffc900060e7050 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 0000000000000010 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffffff896fe520 RDI: 0000000000000286
RBP: ffffc900060e70c0 R08: dffffc0000000000 R09: fffffbfff135f926
R10: fffffbfff135f926 R11: 0000000000000000 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880a4d180e8
FS:  0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000046b5a0 CR3: 00000000a7ac9000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (7):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci-upstream-kasan-gce-smack-root 2020/10/11 12:32 upstream da690031a5d6 4a77ae0b .config console log report syz C
ci-upstream-kasan-gce-smack-root 2020/10/11 08:36 upstream da690031a5d6 4a77ae0b .config console log report syz C
ci-upstream-kasan-gce-selinux-root 2020/09/22 08:23 upstream 98477740630f 9e1fa68e .config console log report syz C
ci-upstream-kasan-gce-root 2020/09/22 08:04 upstream 98477740630f 9e1fa68e .config console log report syz C
ci-upstream-kasan-gce-selinux-root 2020/09/22 07:08 upstream 98477740630f 9e1fa68e .config console log report info
ci-upstream-kasan-gce-root 2020/09/22 06:47 upstream 98477740630f 9e1fa68e .config console log report info
ci-upstream-kasan-gce-root 2020/09/22 06:45 upstream 98477740630f 9e1fa68e .config console log report info
* Struck through repros no longer work on HEAD.