From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 54A9B38D3F0; Wed, 7 Oct 2026 19:49:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791402591; cv=none; b=a53QnEDeCtE9gZFXjvLlIYrLx+inuTSTWjf8jZjDNB2jqbv6t3T43CJfkpBXBwIEs8ySec9aEzQT2K9/RQLaJ0PpB15u9+l+fkmuD95bxfzNi7zLmgPHMe6MQWrkGfXa8dtZAXeEcRgwcTMeEU47ZIA1jHrtJ6YComb5Nllv67k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791402591; c=relaxed/simple; bh=Wdhb3pW7f+y7cF6TjE/est2fJddaFrDQGeAMlxf89aQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=F9xmHpTiEEVKu/VULN61P0Ac3nUnuSO3Bl1WrTl62lUuMsr3mb1SNRudPHjvjzeoJ2KU1AqM4AZiBQRk9C6BBwWU8UOrb2j53pXXw9bn9x2S5g78I0UO4mLRio5EtKdiVFiNPFdQBLw2VRA9EKYLVF9w972PJxRn9qUBqK1WqoM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OXwMJV/O; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OXwMJV/O" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E8B1B1F0089A; Wed, 7 Oct 2026 19:49:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791402590; bh=DINgOqURJ5eGbdb4g7792UX6puWOtU60lJWEbBwVUZ4=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=OXwMJV/OVtSn4t58rnBw4QkCm9FmNgitwDT/nrD80cFtnrl/YIgQT6ij9st8BpfWQ x/eX41E67/EWeH0kTYybLKL4JbGbwR2kXTZAACkdCaEkeegVpNgqUNAiKOtJ/+cG++ eNkmWnKTIqIR+SH99PZY0HZb3iGnMQcUEo3lqJEpiU2w1tOOhDlg/j2IEehtJUJ9Cr chtn3IvwikHrOogNZUC+hPDf3k41bglRN3fsPIpk4cYuQ3rRnBntMiDQdQxGqcyiWU TTqYo3+x2GGGtm4ns+wjwMEzOu4WTOnD81ac2d6R4VFPWTfSJap73I/ziKCC91tXpq SvJhV7unufvmQ== From: Chuck Lever Date: Wed, 07 Oct 2026 15:49:31 -0400 Subject: [PATCH net-next v3 2/9] tls: Check for a pending signal after an empty record 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: <20261007-tls-follow-on-v3-2-6d52d98389b3@kernel.org> References: <20261007-tls-follow-on-v3-0-6d52d98389b3@kernel.org> In-Reply-To: <20261007-tls-follow-on-v3-0-6d52d98389b3@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 0.16-dev-da966 X-Developer-Signature: v=1; a=openpgp-sha256; l=3037; i=cel@kernel.org; h=from:subject:message-id; bh=Wdhb3pW7f+y7cF6TjE/est2fJddaFrDQGeAMlxf89aQ=; b=owEBbQKS/ZANAwAKATNqszNvZn+XAcsmYgBqxqJZxqM/O4r1Wisx3dGvXo/ge7CTlAGv+q/tc k1H+9DBdpCJAjMEAAEKAB0WIQQosuWwEobfJDzyPv4zarMzb2Z/lwUCasaiWQAKCRAzarMzb2Z/ l1aTD/9TLeZQjYqsWAD2rzELmUqsdQuxloSBVcaW3sbiRjdC6deh69yBsKsuEAgZxyJTNP4Sxrq 8pOMu3hrRookQebhwfLoPnNsoK3rODQd+kxDQIhWfihFdeVZfK+Ck6JBpcbSZoD17tc9kQuE+Ef GJDr1nkP7ihEsYmKbayoYI0rFtqT3aLQR6zUS9chi1tbKG+hc8a5spH3uTrkieF++diWuywPY4E +StsSLyAUeJwH0ai7YNG6fIYL8V22cFOPlnQEbiOiDndlVzyiZPtSsZDIeWTmOsmdoDoT9JqSql F04qQAb7gpJ2RCV8njdBuN/mzY4sWrgoLBf/L34NXmvj9PSIpQA0+YyzKqk7DqLXJKqnf6hhNwg 0hjZ1pbr5EQpdfEaKiU16PgN0OLFJlIrXXYwvhw/AqXFf3xiGPjgdkLvboXfDR+zrjEtAQ6phU3 zSb/O0+e4QCUv038vPw/2cmXJxVkZ5RhkvLsgaIwU+MldXoZqAKnf28AqemGI0joSXyaI+KPlFR bHOt+uZHKr5THX8dIBoucpzz4oGXpRx9WdSwgJSzTorodtSkPpGuKplkqWeOt62de2g673y4ZrO tXWFixRnhUohUOhMQuhzT6J9azPFkxaL1F3vjnJyQoXXl+VnEikViPzbx6jtycbc5ODK1sNNFmd /amgDkyiw+fhB6A== 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, and a nonblocking reader gets -EINTR. 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 | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 275a6047da9e..32be5a8f80ed 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1824,6 +1824,7 @@ 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 +1859,16 @@ 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 it sleeps. + */ + if (nodata && signal_pending(current)) { + long timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); + + err = sock_intr_errno(timeo); + goto recv_end; + } + err = tls_rx_rec_wait(sk, flags & MSG_DONTWAIT, released, !!(decrypted + copied)); if (err <= 0) @@ -1874,9 +1885,12 @@ 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 if it + * is 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 +1924,7 @@ 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