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Fri, 26 Aug 2022 01:37:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0EACBC433B5; Fri, 26 Aug 2022 01:37:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1661477855; bh=NmD18uuwN25Do8NTnX2JO0z/0j4qKJpv21ErkV3NsxE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=GjP4I6kx+n1vOS5fuh9FAeuT44KCyJeg9e4p7w1dRtZ54t9IeibSi5rI+1AuSwZ/I xdMlUobKhZjagctu7Qo21vGjbI6jcoHh7cN/8uuNVBU7uX/8nloFYAnFVGFlb4ewsh mqVdcxzsKXoHoXig1oxSylTxKen36xhYYvv2J0FM= Date: Thu, 25 Aug 2022 18:37:34 -0700 From: Andrew Morton To: syzbot Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, willy@infradead.org, Jaegeuk Kim , Chao Yu , linux-f2fs-devel@lists.sourceforge.net Subject: Re: [syzbot] BUG: unable to handle kernel NULL pointer dereference in set_page_dirty Message-Id: <20220825183734.0b08ae10a2e9e1bd156a19cd@linux-foundation.org> In-Reply-To: <000000000000d5b4fe05e7127662@google.com> References: <000000000000d5b4fe05e7127662@google.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (cc fsf2 developers) On Thu, 25 Aug 2022 08:29:32 -0700 syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: a41a877bc12d Merge branch 'for-next/fixes' into for-kernelci > git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci > console output: https://syzkaller.appspot.com/x/log.txt?x=175def47080000 > kernel config: https://syzkaller.appspot.com/x/.config?x=5cea15779c42821c > dashboard link: https://syzkaller.appspot.com/bug?extid=775a3440817f74fddb8c > compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2 > userspace arch: arm64 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+775a3440817f74fddb8c@syzkaller.appspotmail.com > > Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 > Mem abort info: > ESR = 0x0000000086000005 > EC = 0x21: IABT (current EL), IL = 32 bits > SET = 0, FnV = 0 > EA = 0, S1PTW = 0 > FSC = 0x05: level 1 translation fault > user pgtable: 4k pages, 48-bit VAs, pgdp=00000001249cc000 > [0000000000000000] pgd=080000012ee65003, p4d=080000012ee65003, pud=0000000000000000 > Internal error: Oops: 86000005 [#1] PREEMPT SMP > Modules linked in: > CPU: 0 PID: 3044 Comm: syz-executor.0 Not tainted 6.0.0-rc2-syzkaller-16455-ga41a877bc12d #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/20/2022 > pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : 0x0 > lr : folio_mark_dirty+0xbc/0x208 mm/page-writeback.c:2748 > sp : ffff800012803830 > x29: ffff800012803830 x28: ffff0000d02c8000 x27: 0000000000000009 > x26: 0000000000000001 x25: 0000000000000a00 x24: 0000000000000080 > x23: 0000000000000000 x22: ffff0000ef276c00 x21: 05ffc00000000007 > x20: ffff0000f14b83b8 x19: fffffc00036409c0 x18: fffffffffffffff5 > x17: ffff80000dd7a698 x16: ffff80000dbb8658 x15: 0000000000000000 > x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 > x11: ff808000083e9814 x10: 0000000000000000 x9 : ffff8000083e9814 > x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000 > x5 : ffff0000d9028000 x4 : ffff0000d5c31000 x3 : ffff0000d9027f80 > x2 : fffffffffffffff0 x1 : fffffc00036409c0 x0 : ffff0000f14b83b8 > Call trace: > 0x0 > set_page_dirty+0x38/0xbc mm/folio-compat.c:62 > get_next_nat_page+0x198/0x300 fs/f2fs/node.c:154 > __flush_nat_entry_set fs/f2fs/node.c:3005 [inline] > f2fs_flush_nat_entries+0x354/0x988 fs/f2fs/node.c:3109 > f2fs_write_checkpoint+0x350/0x568 fs/f2fs/checkpoint.c:1667 > f2fs_issue_checkpoint+0x1b0/0x234 > f2fs_sync_fs+0x8c/0xc8 fs/f2fs/super.c:1651 > sync_filesystem+0xe0/0x134 fs/sync.c:66 > generic_shutdown_super+0x38/0x190 fs/super.c:474 > kill_block_super+0x30/0x78 fs/super.c:1427 > kill_f2fs_super+0x140/0x184 fs/f2fs/super.c:4544 > deactivate_locked_super+0x70/0xd4 fs/super.c:332 > deactivate_super+0xb8/0xbc fs/super.c:363 > cleanup_mnt+0x1f8/0x234 fs/namespace.c:1186 > __cleanup_mnt+0x20/0x30 fs/namespace.c:1193 > task_work_run+0xc4/0x208 kernel/task_work.c:177 > resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] > do_notify_resume+0x174/0x1d0 arch/arm64/kernel/signal.c:1127 > prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] > exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] > el0_svc+0x9c/0x150 arch/arm64/kernel/entry-common.c:625 > el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:642 > el0t_64_sync+0x18c/0x190 > Code: bad PC value > ---[ end trace 0000000000000000 ]--- > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.