From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail115-100.sinamail.sina.com.cn (mail115-100.sinamail.sina.com.cn [218.30.115.100]) (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 61304161310 for ; Wed, 18 Dec 2024 11:41:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=218.30.115.100 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734522092; cv=none; b=XXqk7irh20VanBF2wht1zqf98dTODjFMaZPq5+K+4EbMBcG1I9fOlSuLkQ0NoWujccVJEeXEe3gmnSB88Sde9epLh+w+CIuMdHENtb1FggXWd3QrP3hlER5RJHX5N5wwS0GhP1LBxvXjdq6oe6c+DzgpwwvPcNA/NYxhniIByxs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734522092; c=relaxed/simple; bh=0DfcjxSl9vpENmce3tmYyg0NWdcTUXJV/1qzGsZOnQk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=rvQm0nelbDNmvqLESu1HHNae982KLfKi/rF9zg1nKJYYab0CHVzlMmpb++Wh2+Ww0/nDujmpVJ8/E8VUklc/+tO/aD3CeSgDjePu3zNviPnCI7NQW/NTcBi7AWRpgxCCQT6TAI32Tar3BJSr/jRLSGCUHmPaQ+/5BltBSdQerGc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; arc=none smtp.client-ip=218.30.115.100 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([116.24.8.58]) by sina.com (10.185.250.23) with ESMTP id 6762B4D8000043C4; Wed, 18 Dec 2024 19:41:17 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 1706208913388 X-SMAIL-UIID: 59CC1986AB074209ABFE54E7DA78DF77-20241218-194117-1 From: Hillf Danton To: syzbot Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [net?] general protection fault in put_page (4) Date: Wed, 18 Dec 2024 19:41:02 +0800 Message-ID: <20241218114106.255-1-hdanton@sina.com> In-Reply-To: <6761aed9.050a0220.29fcd0.006b.GAE@google.com> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On Tue, Dec 17, 2024 at 6:03 PM > syzbot found the following issue on: > > HEAD commit: 78d4f34e2115 Linux 6.13-rc3 > git tree: upstream > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13f502df980000 #syz test --- x/net/core/skbuff.c +++ y/net/core/skbuff.c @@ -1105,7 +1105,9 @@ static void skb_release_data(struct sk_b int i; if (!skb_data_unref(skb, shinfo)) - goto exit; + return; + if (test_and_set_bit(7, &shinfo->flags)) + return; if (skb_zcopy(skb)) { bool skip_unref = shinfo->flags & SKBFL_MANAGED_FRAG_REFS; --