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 575C91C68C; Sun, 1 Sep 2024 16:44:05 +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=1725209045; cv=none; b=qfJDM37uJ3MAkyC5QB5k+kmSixCCjC5zOuljbyj9vRK+dyV81CSq6IO5nxxR5go0Xd8HXhUq9ukno+ZV3yYqBmD/apTnwTaQKx+n8gY+aY1CBEUlOXz8fC15yDD9l4LaE2iTob0U/CYG6gSLhuup8Z4D0+1h9Xi8OJMNOnONkjA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725209045; c=relaxed/simple; bh=XtjYyyplubDm1lzHaU2qxPeOrnObsMW8kmHsQngwuWY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ArzPx7gVrLDl/LrWB5ZTPvPFG54vu1guBOrlwCiN71pa+7S6qKVR2cJNc+8KDXd7Buy4GfP+TQ/SrwEOHtkzE1iecjMWREu4o+GwTeb+9oKA9hf+8lLEl4fhXac3Bmk1z5D5jJwLJ4qdPbg8xpr0q8a77iN0EZebJR8aufW2edk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=goPukHJ7; 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="goPukHJ7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D17A4C4CEC3; Sun, 1 Sep 2024 16:44:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1725209045; bh=XtjYyyplubDm1lzHaU2qxPeOrnObsMW8kmHsQngwuWY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=goPukHJ7kRJkv6MbGHgWZVWqNuZkkfR8oty9X4lWJRMXLICtJCLvuUnOv8Pxsds0l MV7mnvfj7+GM30+7dRRplBTjwM18e67JYeCYUw6iSj8rq2Uaq6xwlSoAupoxCH4a5v 5eazIyhpmCFjdId90Eaw/8SxKjFequRQdFEZLy3c= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+f9db6ff27b9bfdcfeca0@syzkaller.appspotmail.com, syzbot+dcd73ff9291e6d34b3ab@syzkaller.appspotmail.com, Allison Henderson , Paolo Abeni Subject: [PATCH 5.4 116/134] net:rds: Fix possible deadlock in rds_message_put Date: Sun, 1 Sep 2024 18:17:42 +0200 Message-ID: <20240901160814.448553906@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240901160809.752718937@linuxfoundation.org> References: <20240901160809.752718937@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Allison Henderson commit f1acf1ac84d2ae97b7889b87223c1064df850069 upstream. Functions rds_still_queued and rds_clear_recv_queue lock a given socket in order to safely iterate over the incoming rds messages. However calling rds_inc_put while under this lock creates a potential deadlock. rds_inc_put may eventually call rds_message_purge, which will lock m_rs_lock. This is the incorrect locking order since m_rs_lock is meant to be locked before the socket. To fix this, we move the message item to a local list or variable that wont need rs_recv_lock protection. Then we can safely call rds_inc_put on any item stored locally after rs_recv_lock is released. Fixes: bdbe6fbc6a2f ("RDS: recv.c") Reported-by: syzbot+f9db6ff27b9bfdcfeca0@syzkaller.appspotmail.com Reported-by: syzbot+dcd73ff9291e6d34b3ab@syzkaller.appspotmail.com Signed-off-by: Allison Henderson Link: https://lore.kernel.org/r/20240209022854.200292-1-allison.henderson@oracle.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman --- net/rds/recv.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) --- a/net/rds/recv.c +++ b/net/rds/recv.c @@ -424,6 +424,7 @@ static int rds_still_queued(struct rds_s struct sock *sk = rds_rs_to_sk(rs); int ret = 0; unsigned long flags; + struct rds_incoming *to_drop = NULL; write_lock_irqsave(&rs->rs_recv_lock, flags); if (!list_empty(&inc->i_item)) { @@ -434,11 +435,14 @@ static int rds_still_queued(struct rds_s -be32_to_cpu(inc->i_hdr.h_len), inc->i_hdr.h_dport); list_del_init(&inc->i_item); - rds_inc_put(inc); + to_drop = inc; } } write_unlock_irqrestore(&rs->rs_recv_lock, flags); + if (to_drop) + rds_inc_put(to_drop); + rdsdebug("inc %p rs %p still %d dropped %d\n", inc, rs, ret, drop); return ret; } @@ -761,16 +765,21 @@ void rds_clear_recv_queue(struct rds_soc struct sock *sk = rds_rs_to_sk(rs); struct rds_incoming *inc, *tmp; unsigned long flags; + LIST_HEAD(to_drop); write_lock_irqsave(&rs->rs_recv_lock, flags); list_for_each_entry_safe(inc, tmp, &rs->rs_recv_queue, i_item) { rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong, -be32_to_cpu(inc->i_hdr.h_len), inc->i_hdr.h_dport); + list_move(&inc->i_item, &to_drop); + } + write_unlock_irqrestore(&rs->rs_recv_lock, flags); + + list_for_each_entry_safe(inc, tmp, &to_drop, i_item) { list_del_init(&inc->i_item); rds_inc_put(inc); } - write_unlock_irqrestore(&rs->rs_recv_lock, flags); } /*