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 9F2F6189F3C; Wed, 25 Sep 2024 11:37:14 +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=1727264234; cv=none; b=FceA4UnrSEw8BZ4X91pAwJZuYUp3MCxD+xTXfAHM2WJvrhqkXOLgjMHhItQ0FddNgoERQigh6pDzSQ7e7X0WEdrn8ePPCHVCZfT6/aLIZ1FPG7sN+Tc+6kpP1gL4/UOxX+HQ1qOZ3lkmWI3QbVXZHDfy/A0JrTr+yl5JoQJkjy8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727264234; c=relaxed/simple; bh=9lBC4d65KKRSmO1eJbpsc08w5T/98CswSFBKhln48QA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=C8U5FF4t6gc9JyfnP0GY3bMqehqvCORjMy5hU/wECdBpGqEHe/vEx0DIQLXEoLcAg+JjQKymnOW8DnpzelR4tW0yyw1GzslMTJ9Bq+atTJHtx0J9XJsNkPbIQPjs6Q1u8CdX2MK97LusatNP3FP4si8Mp9XarQAuNT1hJqoS9vU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=B5C7opTb; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="B5C7opTb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 117ECC4CECD; Wed, 25 Sep 2024 11:37:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727264234; bh=9lBC4d65KKRSmO1eJbpsc08w5T/98CswSFBKhln48QA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B5C7opTbn+4tfIxcwB/fglu0ae+/Pe5tvihcHSyYjF+6c3dHMlf80gQAx7fXiP9vX Il/e3IS0hfQNX98itZZ1fCqbqbF875x1JueLGRCgbLD30tv1JlFM4YuaQLaBIjmYG8 YtgUTmiF1byN0FlIdX3ar9waFnFWSz8KYphDJFHe8eWUaYStMYIc2THpWhIDXP+UgP x1EfHxfpuzGmnImvMcrNaulG93szBXPc+UIQlTNH7QzdoFktTGaUHT5ifNpihgV5aP gHoiapXuKH6MxLxUcjgsMC5j3/FmJetnACLX3OqMxHX78NOFhIe2cUjuEgVzi4p440 E4ngmJrY3SEQQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jeongjun Park , Jakub Kicinski , Sasha Levin , wei.liu@kernel.org, paul@xen.org, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, xen-devel@lists.xenproject.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 6.11 013/244] net/xen-netback: prevent UAF in xenvif_flush_hash() Date: Wed, 25 Sep 2024 07:23:54 -0400 Message-ID: <20240925113641.1297102-13-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240925113641.1297102-1-sashal@kernel.org> References: <20240925113641.1297102-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.11 Content-Transfer-Encoding: 8bit From: Jeongjun Park [ Upstream commit 0fa5e94a1811d68fbffa0725efe6d4ca62c03d12 ] During the list_for_each_entry_rcu iteration call of xenvif_flush_hash, kfree_rcu does not exist inside the rcu read critical section, so if kfree_rcu is called when the rcu grace period ends during the iteration, UAF occurs when accessing head->next after the entry becomes free. Therefore, to solve this, you need to change it to list_for_each_entry_safe. Signed-off-by: Jeongjun Park Link: https://patch.msgid.link/20240822181109.2577354-1-aha310510@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/xen-netback/hash.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/xen-netback/hash.c b/drivers/net/xen-netback/hash.c index ff96f22648efd..45ddce35f6d2c 100644 --- a/drivers/net/xen-netback/hash.c +++ b/drivers/net/xen-netback/hash.c @@ -95,7 +95,7 @@ static u32 xenvif_new_hash(struct xenvif *vif, const u8 *data, static void xenvif_flush_hash(struct xenvif *vif) { - struct xenvif_hash_cache_entry *entry; + struct xenvif_hash_cache_entry *entry, *n; unsigned long flags; if (xenvif_hash_cache_size == 0) @@ -103,8 +103,7 @@ static void xenvif_flush_hash(struct xenvif *vif) spin_lock_irqsave(&vif->hash.cache.lock, flags); - list_for_each_entry_rcu(entry, &vif->hash.cache.list, link, - lockdep_is_held(&vif->hash.cache.lock)) { + list_for_each_entry_safe(entry, n, &vif->hash.cache.list, link) { list_del_rcu(&entry->link); vif->hash.cache.count--; kfree_rcu(entry, rcu); -- 2.43.0