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 BA71F3F99FD; Tue, 24 Mar 2026 12:54:02 +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=1774356842; cv=none; b=KUQo2Qizvuu/IVg5HHKlKLLKbDxiC0JVxSZPUAhJbEIuVh8FCF6X7rUhutedfG3o5WkzcPYQ2pvD0w08fuXbxOJ1jvEANajG0UpyJZfLi3AB1KC3sEGvqotWR3vyYOX2KQ/OFDp5xj9w1uRJWK/aqUSIazpBjRcm6neLfPT+7K0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774356842; c=relaxed/simple; bh=ADsowbatqb/2SsLJ3HQ7L93bqVYsEjgbcxdwOPOvHEM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=q43xkh2pf50mhqzHDeNcOgYGH+JdtmOuq14OD4+L4fSxBY2DUofVG+3+eAi9OAxhspA/AtuJKnCSTb3Qv4eBAys5ds7nKna5PnuVx4zahkewvMIqbqjis5x4xxQ+D1PHa9rqmnNclQoz14QizLWVVlAYbfwBKpfJTPB7A6rUFb0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Zx91Cyqn; 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="Zx91Cyqn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 105D7C2BC87; Tue, 24 Mar 2026 12:54:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774356842; bh=ADsowbatqb/2SsLJ3HQ7L93bqVYsEjgbcxdwOPOvHEM=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=Zx91Cyqnkt8uMg350UhoXhoGiTNI3QPQH4l0QYR2SHV5pT5yTmra3/UI0OIX21Y8J p886rCg30HTA68wgkAT3Zw56fUgRt3uJeef9BybcAHROo9HlEDdo5dYjUm4KZTZHle jr9EBfahZuIgRgstDHnVZ462MNVA/xsZk2URcaYPHoQQ7nGq6pNLnG/k4unpj6Vabg +GjrnEvW56NoGHHen9EwE/mAYvpEXBdZNKT7hWVT0mvbekwcv9g1dq4LYIJKfbQEAC fkaWgi1zn+aHL1ceTQceTbWSnDotv0mHRo31e8SpeUIGQxQx6xEnNF+db9j0uL8vl/ ojVi7mW7/TExw== From: Chuck Lever Date: Tue, 24 Mar 2026 08:53:25 -0400 Subject: [PATCH net-next v5 3/6] tls: Fix dangling skb pointer in tls_sw_read_sock() Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260324-tls-read-sock-v5-3-5408befe5774@oracle.com> References: <20260324-tls-read-sock-v5-0-5408befe5774@oracle.com> In-Reply-To: <20260324-tls-read-sock-v5-0-5408befe5774@oracle.com> To: john.fastabend@gmail.com, kuba@kernel.org, sd@queasysnail.net Cc: netdev@vger.kernel.org, kernel-tls-handshake@lists.linux.dev, Chuck Lever , Hannes Reinecke , Alistair Francis X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1636; i=chuck.lever@oracle.com; h=from:subject:message-id; bh=C6Eyt3fovBhxmJhtF8FQJ86E45z3fVSEaLjEsfKU3NA=; b=owEBbQKS/ZANAwAKATNqszNvZn+XAcsmYgBpwolnsXDk0WH80WoYeU6k0cmu667v0B5zeroba 8PFXjttiFeJAjMEAAEKAB0WIQQosuWwEobfJDzyPv4zarMzb2Z/lwUCacKJZwAKCRAzarMzb2Z/ l3YTEAC6byauf931LeW5aUqpW0+Z6ie5PjpOvAMPq+XTHmIZ30jw2RI8oWR9386+Q0TV0Yn4IYI IzVKtengbhwjh5tI3VT+bkhCLC3+URoT2xL1zboKEzgSCCFkHTpWMWTGwoDgnXa6OAhn1kMEAVv kWNlJAPxZvwtYdXH0f+QjuamKTanF9m+5cE/1davveacric7/xKoWocKG+m16FK+lS6hybSPZ5z UPcwxsafe/Za3P28tr/jhmLV+wmbLga+jAJiX/fatqdIDRT3q6xGQS2AGVQAfPbQQGVfc5DdEm6 2Id+QB9+e4ZxmT+TuAKOSRH5IuaX92CDOgS3K+8x/DWOiNCf5xgGWrXj3bXNK/e20/hkIcXPwpd XDQqtyLeMYx7pL/2+MyEzI3CWemxweZj1X3B5rAS81ECmPU87kNy91HDRPoELTo1yTc5f+r4DHy xHBHeyXxU774mEi2rZ1XuvfLyVVUiPA1qx+6z2lFVx03SRYH36gLvDiZO1jlV6s8dV1mwN4R49I acLsSVLt2/Yhv4/TbBqg28bAchfWaQOfzfSFmC3IYmyhY0VdWUQyHSZo2lilQM2/mniLKYmmuqy Dx/IOXqgE7GYJVUCY9Ea5V/u94+kRcZEF5TNjIyHRpSuxJChaAbcFYIE7qxTJxKFrRYRaNTMhEY YlRpPCPfMolsTiA== X-Developer-Key: i=chuck.lever@oracle.com; a=openpgp; fpr=28B2E5B01286DF243CF23EFE336AB3336F667F97 From: Chuck Lever Per ISO/IEC 9899:2011 section 6.2.4p2, a pointer value becomes indeterminate when the object it points to reaches the end of its lifetime; Annex J.2 classifies the use of such a value as undefined behavior. In tls_sw_read_sock(), consume_skb(skb) in the fully-consumed path frees the skb, but the "do { } while (skb)" loop condition then evaluates that freed pointer. Although the value is never dereferenced -- the loop either continues and overwrites skb, or exits -- any future change that adds a dereference between consume_skb() and the loop condition would produce a silent use-after-free. Fixes: 662fbcec32f4 ("net/tls: implement ->read_sock()") Reviewed-by: Hannes Reinecke Reviewed-by: Alistair Francis Signed-off-by: Chuck Lever --- net/tls/tls_sw.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 5626fdd4ea0a..5fdd43a55f1e 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -2356,7 +2356,7 @@ int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc, goto read_sock_end; decrypted = 0; - do { + for (;;) { if (!skb_queue_empty(&ctx->rx_list)) { skb = __skb_dequeue(&ctx->rx_list); rxm = strp_msg(skb); @@ -2405,10 +2405,11 @@ int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc, goto read_sock_requeue; } else { consume_skb(skb); + skb = NULL; if (!desc->count) - skb = NULL; + break; } - } while (skb); + } read_sock_end: tls_rx_reader_release(sk, ctx); -- 2.53.0