From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792428934; b=C339tM6iomPSSW+I8gU3rYKOhFFLd4Rumc5cA0+EtczG9TUj0hN9SEl8MhYSzgSrgHAi f9w7JhZORkoxCCzVEE5WCGAtU484kX5xch10SVr83deEtXuvGjzdNHNkVhHpu3DcLMfKP R1mD8V1P2QOfARZG8GbtGZaiPyy37Hbg4BJrb0MwegzBdpgj1QKPgywG/fR96tyPM8O1G xCPg+Jb5QTPWx+HoWIWDgiqkfACG3u8UUh1wa81bOggXBgEMphmMuqnGYq+WEHlC/ntS+ n1BHTF6ZIB8BUrTjgZnlIPPh0d7WSe5J74VKiwUEl+kmKifsmCFmkgijdXD38MM32YQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792428934; h=Received:DKIM-Signature:From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:References:In-Reply-To:To:Cc: X-Mailer:X-Developer-Signature:X-Developer-Key; bh=413E26pmnObogmjRvlgsF2MjO9P7v6cLOObeHeXQYEM=; b=xiMjd5TNjQ0jBaT7NRix5wgXMfGZ3/Glvd7h9zt1APEkBiNCr3X+Ee0dfCnTmDV1tkJp l3ZvgF+rrx3FXuOJW5XaHHpjroQUtJGJz2WkWIhTYcZXeW2GBUn4O6e/wNBjLHxvFGzHV ZT9PK8VciP8sodUGHYtDgIf/+Maax9BdqnuOSoItB9tBBdkSBv/0DwyHP3WLQyBTdFgIT fA2BK3oj7YNhH9c1JpR8LWOruJJQBDAV8zYCZpu+3/midi44tbLzddld95On1mTL0PAR8 i2vp0s5kzmgBA14UUmY9nBYIWImFhqkrIgE8aqp0/jufKrquUXcvBZ4BIonR2FK7I+Q== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=M80EyCNj; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 229C1606A326; Mon, 19 Oct 2026 16:55:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=M80EyCNj Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD4A61F000C4; Mon, 19 Oct 2026 16:55:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792428934; bh=413E26pmnObogmjRvlgsF2MjO9P7v6cLOObeHeXQYEM=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=M80EyCNjt1dhH5PqJSqka27fUsXHw/kGwa6VmQPSq87VkhaTqww6P9JA9dluOOjWm ce0kmBfk6+s/csK2TmxsbA3gVZL5BQeI6N8c+zIYGJoA/ShbQXvofO2J/yCFZqQHtD 1OVR7j4fNGogiasxt7/8IhQV6C6aMZVrVW5Av/+eQZUKjVs6icaO9fv+eoJJVP5cLC ujmxH03iGbRcEPpB1pzEAdru4OhLDCDAdvYZYgg2o/MPj/9WT+AG/M0bxIccr259S4 9xxClp3pb4vIV+F74b8S8uKdbOsWzGrdEE5s0O+8euf9RpT5fRtygEyTI9LZsklBGV P5GeX6cBUgjQw== From: Chuck Lever Date: Mon, 19 Oct 2026 12:55:18 -0400 Subject: [PATCH net-next v6 2/9] tls: Check for a pending signal after an empty record X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261019-tls-follow-on-v6-2-ab01c4ecca0c@kernel.org> References: <20261019-tls-follow-on-v6-0-ab01c4ecca0c@kernel.org> In-Reply-To: <20261019-tls-follow-on-v6-0-ab01c4ecca0c@kernel.org> To: John Fastabend , Jakub Kicinski , Sabrina Dubroca , "David S. Miller" , Paolo Abeni , Simon Horman , Chuck Lever , Dave Watson , Shuah Khan , Qingfang Deng , Eric Dumazet Cc: netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, sashiko-bot X-Mailer: b4 0.17-dev-9c833 X-Developer-Signature: v=1; a=openpgp-sha256; l=3923; i=cel@kernel.org; h=from:subject:message-id; bh=LEaa/zPrbZyrUKVGzo2eVQ0L46Z0zDzVvnXIjPTfq0c=; b=owEBbQKS/ZANAwAKATNqszNvZn+XAcsmYgBq1kuA1hhegB5Ns5vw93gVtegy/E5yvwD6wvI2g dDNykOHg3mJAjMEAAEKAB0WIQQosuWwEobfJDzyPv4zarMzb2Z/lwUCatZLgAAKCRAzarMzb2Z/ l1JzEACehNO3EK7cRrxaxX93kl+d3b2bAf8o5v3OilOajEK6cjuM3m1KryzcCgGTbk/b+iWO37x QH4MWooKXyHjf0G/0I1DA8QmBGdbnMbNeS7fQaqkxpDlV7vqA6GoM5BgVLZciD7y88YJPSOyavR /+5lKXVwWNDFOd37kWUudU3miro0OHUh08htabaL2oqdqOK7d2cxyox3oEcHSHLHsqShKBdkYeT F1GfOLbkcgWmryYkBjHvCt631YN1GcLhDDhShLWj+RD+FhOxQrTZb9jIs663fy4CJeGeDhOSSWD crFeNUVMkS3oWo1gr2qhEWt65nRdMuE3j8ZIVX5zl3tAx2cWQ3ESRTTyNQQ6q9bxAjzQdHu3UKM 54k4hR1DNp+z5xMzSI9w9L8KwKA1U+ut79+W/p7LX9HxSxoUTf3YqaEfhugX+dbRql8aN6c9jTk Kn2jJBCpgyb4g2ZzyLJa8sny4XPSCZG6U+JrmC9JWqhRBO1uXbsYS+tLqB8hk6u37Dd3NoaIx7s aiV8ffihecQAniRw+gtA089ffdFXYtF5XDwtoP5SW8UJ/pTmHHCmNv/+9SswGG1KdXVog1vfaLO Bj1irtcO1XVx1+5Wp3ti5/g0jniPnHWR7AUtkvjS1ynrPaRNQ8nVBnE4mAj8nEOeCfT/LiOHLH4 +/oWYG9npkpqHFQ== X-Developer-Key: i=cel@kernel.org; a=openpgp; fpr=28B2E5B01286DF243CF23EFE336AB3336F667F97 tls_rx_rec_wait() tests signal_pending() only after it sleeps, and it skips the wait loop when a record is already parsed. tls_sw_recvmsg() calls tls_rx_rec_wait() once per record, and a zero-length application_data record does not advance either bound of the receive loop. A peer that streams such records holds the caller in recvmsg(), unresponsive to SIGKILL, for as long as they arrive. The hang has not been reproduced. Test for a pending signal in tls_sw_recvmsg() before it fetches the record after an empty one. A reader that has copied data gets the data. A nonblocking reader with a signal pending gets -EAGAIN rather than -EINTR. Pending task work alone makes signal_pending() true, and io_uring retries a nonblocking receive only on -EAGAIN. The test stays out of tls_rx_rec_wait() because tls_sw_read_sock() also calls tls_rx_rec_wait(), from callers that cannot act on a signal. Decrypt an empty record synchronously. The code at recv_end overwrites err once any record has been decrypted asynchronously. With only empty records queued, the reader then gets zero, not the errno. Fixes: c46234ebb4d1 ("tls: RX path for ktls") Reported-by: sashiko-bot Closes: https://sashiko.dev/#/patchset/20260720-tcp-read-sock-v2-0-29545d034f3c@kernel.org?part=1 Signed-off-by: Chuck Lever --- net/tls/tls_sw.c | 27 ++++++++++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-) diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 0ef0edd51edd..e8a9f0c91e81 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1734,6 +1734,14 @@ tls_read_flush_backlog(struct sock *sk, struct tls_prot_info *prot, return sk_flush_backlog(sk); } +/* io_uring retries a nonblocking receive only on -EAGAIN. */ +static int tls_rx_signal_err(struct sock *sk, bool nonblock) +{ + long timeo = sock_rcvtimeo(sk, nonblock); + + return timeo ? sock_intr_errno(timeo) : -EAGAIN; +} + static int tls_rx_reader_acquire(struct sock *sk, struct tls_sw_context_rx *ctx, bool nonblock) { @@ -1755,7 +1763,7 @@ static int tls_rx_reader_acquire(struct sock *sk, struct tls_sw_context_rx *ctx, if (timeo <= 0) return -EAGAIN; if (signal_pending(current)) - return sock_intr_errno(timeo); + return tls_rx_signal_err(sk, nonblock); if (ret < 0) return ret; } @@ -1824,6 +1832,7 @@ int tls_sw_recvmsg(struct sock *sk, bool is_peek = flags & MSG_PEEK; bool rx_more = false; bool released = true; + bool nodata = false; bool zc_capable; if (unlikely(flags & MSG_ERRQUEUE)) @@ -1858,6 +1867,14 @@ int tls_sw_recvmsg(struct sock *sk, struct tls_decrypt_arg darg; int to_decrypt, chunk; + /* A run of empty records advances neither loop bound, and + * tls_rx_rec_wait() tests for a signal only after sleeping. + */ + if (nodata && signal_pending(current)) { + err = tls_rx_signal_err(sk, flags & MSG_DONTWAIT); + goto recv_end; + } + err = tls_rx_rec_wait(sk, flags & MSG_DONTWAIT, released, !!(decrypted + copied)); if (err <= 0) @@ -1874,9 +1891,12 @@ int tls_sw_recvmsg(struct sock *sk, tlm->control == TLS_RECORD_TYPE_DATA) darg.zc = true; - /* Do not use async mode if record is non-data */ + /* Do not use async mode if record is non-data or empty. + * Once a record has gone async, recv_end discards the + * error that ends a run of empty records. + */ if (tlm->control == TLS_RECORD_TYPE_DATA) - darg.async = ctx->async_capable; + darg.async = ctx->async_capable && to_decrypt; else darg.async = false; @@ -1910,6 +1930,7 @@ int tls_sw_recvmsg(struct sock *sk, /* TLS 1.3 may have updated the length by more than overhead */ rxm = strp_msg(darg.skb); chunk = rxm->full_len; + nodata = !chunk; tls_rx_rec_done(ctx); if (!darg.zc) { -- 2.55.0