From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9C19C20C328; Wed, 6 Nov 2024 20:33:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730925236; cv=none; b=AvhkkkUZ75OD7hjzxzfb5o1fzsPL7o3oCY9/JlHE6q8TMFIpdn8CIJEf3tD9+a/lHBpLB5Dlhr9/PrR3JLlyF7usTHy2WXgw3HSpKHuyntz44xjpYDmrZsHlMZjrXUYYjTnlAa+AnwZvtT6amHPJXXSJB1ATDPIDyfZqg8ot58Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730925236; c=relaxed/simple; bh=bFm3H5xaKjdBfPTeKzQYKQ/MDJtJzswxi5/1angTsas=; h=Date:To:From:Subject:Message-Id; b=Vd4XsVIDPlOaynZOzzVhzyLOvm3sQPk+fyWGDnKInMctJ7vIc4izC0jJYJ+QnMf2teJY2/3GiLY4I4puPxN2WUh0Dw/cHAMY8UMdvG2xTWDGzBEgV8tho6NyYhlT6Tll3riO/2aE5/5Xe1eYWhv1V4k/eiSFyM4kw2L+M9R/+uU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=GUuU01Zr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="GUuU01Zr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17F85C4CEC6; Wed, 6 Nov 2024 20:33:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1730925236; bh=bFm3H5xaKjdBfPTeKzQYKQ/MDJtJzswxi5/1angTsas=; h=Date:To:From:Subject:From; b=GUuU01Zr6HuZqI+JLRGu1FOJ3ql6+/9L4a73XsPKwx330U+TaIbxt/f1mFVjkoPm3 upWvUMpl9uigNu+3RzhHXWP1ABETb7St7huEQtZveNoPwgXmCjYgzexAqzfX1hodxo u2JjEoawI6gyzMgdPXgdw54Wdq+/TTuRxmBkKSTQ= Date: Wed, 06 Nov 2024 12:33:55 -0800 To: mm-commits@vger.kernel.org,tj@kernel.org,stable@vger.kernel.org,bugreport@valiantsec.com,konishi.ryusuke@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: + nilfs2-fix-null-ptr-deref-in-block_touch_buffer-tracepoint.patch added to mm-hotfixes-unstable branch Message-Id: <20241106203356.17F85C4CEC6@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: nilfs2: fix null-ptr-deref in block_touch_buffer tracepoint has been added to the -mm mm-hotfixes-unstable branch. Its filename is nilfs2-fix-null-ptr-deref-in-block_touch_buffer-tracepoint.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/nilfs2-fix-null-ptr-deref-in-block_touch_buffer-tracepoint.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Ryusuke Konishi Subject: nilfs2: fix null-ptr-deref in block_touch_buffer tracepoint Date: Thu, 7 Nov 2024 01:07:32 +0900 Patch series "nilfs2: fix null-ptr-deref bugs on block tracepoints". This series fixes null pointer dereference bugs that occur when using nilfs2 and two block-related tracepoints. This patch (of 2): It has been reported that when using "block:block_touch_buffer" tracepoint, touch_buffer() called from __nilfs_get_folio_block() causes a NULL pointer dereference, or a general protection fault when KASAN is enabled. This happens because since the tracepoint was added in touch_buffer(), it references the dev_t member bh->b_bdev->bd_dev regardless of whether the buffer head has a pointer to a block_device structure. In the current implementation, the block_device structure is set after the function returns to the caller. Here, touch_buffer() is used to mark the folio/page that owns the buffer head as accessed, but the common search helper for folio/page used by the caller function was optimized to mark the folio/page as accessed when it was reimplemented a long time ago, eliminating the need to call touch_buffer() here in the first place. So this solves the issue by eliminating the touch_buffer() call itself. Link: https://lkml.kernel.org/r/20241106160811.3316-1-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/20241106160811.3316-2-konishi.ryusuke@gmail.com Fixes: 5305cb830834 ("block: add block_{touch|dirty}_buffer tracepoint") Signed-off-by: Ryusuke Konishi Reported-by: Ubisectech Sirius Closes: https://lkml.kernel.org/r/86bd3013-887e-4e38-960f-ca45c657f032.bugreport@valiantsec.com Reported-by: syzbot+9982fb8d18eba905abe2@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9982fb8d18eba905abe2 Tested-by: syzbot+9982fb8d18eba905abe2@syzkaller.appspotmail.com Cc: Tejun Heo Cc: Signed-off-by: Andrew Morton --- fs/nilfs2/page.c | 1 - 1 file changed, 1 deletion(-) --- a/fs/nilfs2/page.c~nilfs2-fix-null-ptr-deref-in-block_touch_buffer-tracepoint +++ a/fs/nilfs2/page.c @@ -39,7 +39,6 @@ static struct buffer_head *__nilfs_get_f first_block = (unsigned long)index << (PAGE_SHIFT - blkbits); bh = get_nth_bh(bh, block - first_block); - touch_buffer(bh); wait_on_buffer(bh); return bh; } _ Patches currently in -mm which might be from konishi.ryusuke@gmail.com are nilfs2-fix-null-ptr-deref-in-block_touch_buffer-tracepoint.patch nilfs2-fix-null-ptr-deref-in-block_dirty_buffer-tracepoint.patch