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 EE6421B0109; Wed, 20 Nov 2024 12:59:58 +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=1732107599; cv=none; b=XPtbCVrxmo2kAKGfu9C5bztyLfrEVjpk5cy73JTPzw9cmmf4c7T2Pex5p02N+RCKLksgeZXsrl72SOmV8LzyoEF3gb31Igo7uoFLzyez4x8d8tx3950+1HK+FbSh/qwHzC5jZICgSEtyAKplZ82oIqlYOQ90aZHctpwkas8ejS0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732107599; c=relaxed/simple; bh=2VcO19Q9HcwXQXMuMCEgtJqY+qt7b/NrAHviBceylVg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FQhM3efWJgzvwQwKizELO7vWvoENluX3PnaKuJcUquROKH9sWPdRNAZZvTpR4AjOWsV5upm/ELuyv7KORpPUN2yjux5E9iq1WXzgvHA5bBDryDiD7ftM2puqzthffaP3kMuJa/XS7mwyQaqXr+cH8Ot8UYzUnOlEFUtTA/9KOUM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=AbbmQLD8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="AbbmQLD8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4A1BC4CECD; Wed, 20 Nov 2024 12:59:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1732107598; bh=2VcO19Q9HcwXQXMuMCEgtJqY+qt7b/NrAHviBceylVg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AbbmQLD83m+Z87ShX9GR5YtGnI1QC8QUaLkDSYS7hegAhsZ/M8hyyIBQiwPBxTWLA kb/BNwVOOnCHeNPvGVKxeF19K+FYxHlKIu9hrsNUfRcYWWFYA6UGzFENNUUkUlb/3u /Xr4SfjAB6rbg9COrRKElzPQH8uS6pHP0FoFm40E= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ryusuke Konishi , Ubisectech Sirius , syzbot+9982fb8d18eba905abe2@syzkaller.appspotmail.com, Tejun Heo , Andrew Morton Subject: [PATCH 6.6 39/82] nilfs2: fix null-ptr-deref in block_touch_buffer tracepoint Date: Wed, 20 Nov 2024 13:56:49 +0100 Message-ID: <20241120125630.493661035@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241120125629.623666563@linuxfoundation.org> References: <20241120125629.623666563@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ryusuke Konishi commit cd45e963e44b0f10d90b9e6c0e8b4f47f3c92471 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- fs/nilfs2/page.c | 1 - 1 file changed, 1 deletion(-) --- a/fs/nilfs2/page.c +++ b/fs/nilfs2/page.c @@ -39,7 +39,6 @@ __nilfs_get_page_block(struct page *page first_block = (unsigned long)index << (PAGE_SHIFT - blkbits); bh = nilfs_page_get_nth_block(page, block - first_block); - touch_buffer(bh); wait_on_buffer(bh); return bh; }