syzbot


BUG: unable to handle kernel NULL pointer dereference in generic_perform_write (2)
Status: fixed on 2020/07/17 17:58
Reported-by: syzbot+bca9799bf129256190da@syzkaller.appspotmail.com
Fix commit: 829b37b8 ext4: avoid race conditions when remounting with options that change dax
First crash: 124d, last: 122d

Cause bisection: introduced by (bisect log):

commit 5f0663bb4a64f588f0a2dd6d1be68d40f9af0086
Author: Dan Williams <dan.j.williams@intel.com>
Date: Thu Dec 21 20:25:11 2017 +0000

  ext4, dax: introduce ext4_dax_aops

Crash: BUG: unable to handle kernel NULL pointer dereference in __generic_file_write_iter (log)
Repro: syz .config
similar bugs (3):
Kernel Title Repro Bisected Count Last Reported Patched Status
linux-4.19 BUG: unable to handle kernel NULL pointer dereference in generic_perform_write 2 307d 389d 0/1 auto-closed as invalid on 2020/02/07 03:38
upstream BUG: unable to handle kernel NULL pointer dereference in generic_perform_write 2 286d 343d 0/17 auto-closed as invalid on 2020/01/28 20:19
linux-4.19 BUG: unable to handle kernel NULL pointer dereference in generic_perform_write (2) C fix 1 52d 142d 1/1 fixed on 2020/07/21 02:08
Patch testing requests:
Created Duration User Patch Repo Result
2020/06/10 22:07 21m tytso@mit.edu https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git 5749fe5af3db176659978718ddaecebb450cdb6b OK
2020/06/10 21:41 13m tytso@mit.edu https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git 5b8b9d0c6d0e0f1993c6c56deaf9646942c49d94 report log
2020/06/10 21:10 0m tytso@mit.edu https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 5b8b9d0c6d0e0f1993c6c56deaf9646942c49d94 error
2020/04/15 04:35 18m tytso@mit.edu patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 5b8b9d0c6d0e0f1993c6c56deaf9646942c49d94 OK

Sample crash report:

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro Maintainers
ci-upstream-kasan-gce-selinux-root 2020/04/11 21:35 upstream 5b8b9d0c a8c6a3f8 .config log report syz C akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci-upstream-kasan-gce-smack-root 2020/04/12 02:40 upstream 5b8b9d0c a8c6a3f8 .config log report syz akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci-upstream-kasan-gce-root 2020/04/10 06:06 upstream 5d30bcac a8c6a3f8 .config log report syz akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org