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 972BF33F8A2; Sat, 30 May 2026 17:45:05 +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=1780163106; cv=none; b=Uqaq67FVlBFa0q+6n0zYJoE3x+jnJfsW0TS1aOSAL4+QMbxHwoWsVYCkc3Fe9SuwfA6C1Y0Tce3dHG6VNxCYQsh4tVkQMEswOSVPsisWeXnH3HeJoBHJzw2f2hjN/77Wt+SOKDrmSdLOqhV8PCusOmMo+U6ddwf8lzz2IbAbI6k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780163106; c=relaxed/simple; bh=a35hfQEFGCRu2z5EKFLZEDIKYd1tVzZTA3/tbkpyT+w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=e6ZN6gvzmrMpwBjh0jpce5JSasVaIY2G/ytP0gcCaY1pEPnDG3StYIECk9SQ2EWu5A1fGz8DnK6aWvH+DcmCmfPLu6TnATtd6D3bRrF0dskaSehGGq6lnSpe1H3AD7BRgSNqlBZVw6T5C5xYWYDdo7SpB3XmZlvHBsTjQ5cGNWQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bAeHeEAC; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="bAeHeEAC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DBFBA1F00893; Sat, 30 May 2026 17:45:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780163105; bh=0lZIkks0Vv3nr9Jm6ZTMOVMZ3frievWaBACBvtGKtl8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bAeHeEACRnuH/KIu5ExQqcKc6iWzLzeHfwgjb3DpOIiez3eEsgMxV5lwxj3xQSqqU v4KN0suyvLiU6tCBlYTGMhZXALlpwEP+H8GxaqzeA9J8Ykj7hxHbOW57NYJar8ahJv NH3azfxuwNXbD5XfmX4onXI3QX4Wz0kgfuVMBLVk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Faith , Pumpkin Chang , David Howells , Marc Dionne , Jakub Kicinski , Jay Wang Subject: [PATCH 5.15 156/776] rxrpc: Fix recvmsg() unconditional requeue Date: Sat, 30 May 2026 17:57:50 +0200 Message-ID: <20260530160244.500264469@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160240.228940103@linuxfoundation.org> References: <20260530160240.228940103@linuxfoundation.org> User-Agent: quilt/0.69 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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Howells [ Upstream commit 2c28769a51deb6022d7fbd499987e237a01dd63a ] If rxrpc_recvmsg() fails because MSG_DONTWAIT was specified but the call at the front of the recvmsg queue already has its mutex locked, it requeues the call - whether or not the call is already queued. The call may be on the queue because MSG_PEEK was also passed and so the call was not dequeued or because the I/O thread requeued it. The unconditional requeue may then corrupt the recvmsg queue, leading to things like UAFs or refcount underruns. Fix this by only requeuing the call if it isn't already on the queue - and moving it to the front if it is already queued. If we don't queue it, we have to put the ref we obtained by dequeuing it. Also, MSG_PEEK doesn't dequeue the call so shouldn't call rxrpc_notify_socket() for the call if we didn't use up all the data on the queue, so fix that also. Fixes: 540b1c48c37a ("rxrpc: Fix deadlock between call creation and sendmsg/recvmsg") Reported-by: Faith Reported-by: Pumpkin Chang Signed-off-by: David Howells Acked-by: Marc Dionne Signed-off-by: Jakub Kicinski Cc: stable@vger.kernel.org [Adapted to 5.15: use write_lock_bh/write_unlock_bh, trace_rxrpc_call directly for see-call tracing, 5.15 trace enum naming convention, and added entries to both plain enum and EM() macro list.] Signed-off-by: Jay Wang Signed-off-by: Greg Kroah-Hartman --- include/trace/events/rxrpc.h | 8 ++++++++ net/rxrpc/recvmsg.c | 22 ++++++++++++++++++---- 2 files changed, 26 insertions(+), 4 deletions(-) --- a/include/trace/events/rxrpc.h +++ b/include/trace/events/rxrpc.h @@ -93,9 +93,13 @@ enum rxrpc_call_trace { rxrpc_call_put_notimer, rxrpc_call_put_timer, rxrpc_call_put_userid, + rxrpc_call_put_recvmsg_peek_nowait, rxrpc_call_queued, rxrpc_call_queued_ref, rxrpc_call_release, + rxrpc_call_see_recvmsg_requeue, + rxrpc_call_see_recvmsg_requeue_first, + rxrpc_call_see_recvmsg_requeue_move, rxrpc_call_seen, }; @@ -291,9 +295,13 @@ enum rxrpc_tx_point { EM(rxrpc_call_put_notimer, "PnT") \ EM(rxrpc_call_put_timer, "PTM") \ EM(rxrpc_call_put_userid, "Pus") \ + EM(rxrpc_call_put_recvmsg_peek_nowait, "PpN") \ EM(rxrpc_call_queued, "QUE") \ EM(rxrpc_call_queued_ref, "QUR") \ EM(rxrpc_call_release, "RLS") \ + EM(rxrpc_call_see_recvmsg_requeue, "SrQ") \ + EM(rxrpc_call_see_recvmsg_requeue_first,"SrF") \ + EM(rxrpc_call_see_recvmsg_requeue_move, "SrM") \ E_(rxrpc_call_seen, "SEE") #define rxrpc_transmit_traces \ --- a/net/rxrpc/recvmsg.c +++ b/net/rxrpc/recvmsg.c @@ -607,7 +607,8 @@ try_again: if (after(call->rx_top, call->rx_hard_ack) && call->rxtx_buffer[(call->rx_hard_ack + 1) & RXRPC_RXTX_BUFF_MASK]) - rxrpc_notify_socket(call); + if (!(flags & MSG_PEEK)) + rxrpc_notify_socket(call); break; default: ret = 0; @@ -642,11 +643,24 @@ error_unlock_call: error_requeue_call: if (!(flags & MSG_PEEK)) { write_lock_bh(&rx->recvmsg_lock); - list_add(&call->recvmsg_link, &rx->recvmsg_q); - write_unlock_bh(&rx->recvmsg_lock); + if (list_empty(&call->recvmsg_link)) { + list_add(&call->recvmsg_link, &rx->recvmsg_q); + trace_rxrpc_call(call->debug_id, + rxrpc_call_see_recvmsg_requeue, + refcount_read(&call->ref), + __builtin_return_address(0), NULL); + write_unlock_bh(&rx->recvmsg_lock); + } else if (list_is_first(&call->recvmsg_link, &rx->recvmsg_q)) { + write_unlock_bh(&rx->recvmsg_lock); + rxrpc_put_call(call, rxrpc_call_see_recvmsg_requeue_first); + } else { + list_move(&call->recvmsg_link, &rx->recvmsg_q); + write_unlock_bh(&rx->recvmsg_lock); + rxrpc_put_call(call, rxrpc_call_see_recvmsg_requeue_move); + } trace_rxrpc_recvmsg(call, rxrpc_recvmsg_requeue, 0, 0, 0, 0); } else { - rxrpc_put_call(call, rxrpc_call_put); + rxrpc_put_call(call, rxrpc_call_put_recvmsg_peek_nowait); } error_no_call: release_sock(&rx->sk);