From unknown Sat Aug 16 12:44:33 2025 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-Mailer: MIME-tools 5.509 (Entity 5.509) Content-Type: text/plain; charset=utf-8 From: bug#36364 <36364@debbugs.gnu.org> To: bug#36364 <36364@debbugs.gnu.org> Subject: Status: Potential SSH session exhaustion Reply-To: bug#36364 <36364@debbugs.gnu.org> Date: Sat, 16 Aug 2025 19:44:33 +0000 retitle 36364 Potential SSH session exhaustion reassign 36364 guix submitter 36364 zerodaysfordays@sdf.lonestar.org (Jakob L. Kreuze) severity 36364 normal thanks From debbugs-submit-bounces@debbugs.gnu.org Mon Jun 24 13:30:45 2019 Received: (at submit) by debbugs.gnu.org; 24 Jun 2019 17:30:45 +0000 Received: from localhost ([127.0.0.1]:57896 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hfSni-0006MZ-Ft for submit@debbugs.gnu.org; Mon, 24 Jun 2019 13:30:43 -0400 Received: from lists.gnu.org ([209.51.188.17]:43005) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hfSng-0006MP-Nq for submit@debbugs.gnu.org; Mon, 24 Jun 2019 13:30:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46401) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hfSne-000749-SH for bug-guix@gnu.org; Mon, 24 Jun 2019 13:30:40 -0400 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on eggs.gnu.org X-Spam-Level: X-Spam-Status: No, score=0.8 required=5.0 tests=BAYES_50,RCVD_IN_DNSWL_NONE, URIBL_BLOCKED autolearn=disabled version=3.3.2 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hfSnc-0008Cf-Kl for bug-guix@gnu.org; Mon, 24 Jun 2019 13:30:38 -0400 Received: from mx.sdf.org ([205.166.94.20]:53652) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hfSnb-0007zz-Sg for bug-guix@gnu.org; Mon, 24 Jun 2019 13:30:36 -0400 Received: from Epsilon (pool-173-76-53-40.bstnma.fios.verizon.net [173.76.53.40]) (authenticated (0 bits)) by mx.sdf.org (8.15.2/8.14.5) with ESMTPSA id x5OHOwTV022033 (using TLSv1.2 with cipher AES256-GCM-SHA384 (256 bits) verified NO) for ; Mon, 24 Jun 2019 17:25:11 GMT From: zerodaysfordays@sdf.lonestar.org (Jakob L. Kreuze) To: bug-guix@gnu.org Subject: Potential SSH session exhaustion Date: Mon, 24 Jun 2019 13:23:31 -0400 Message-ID: <87pnn2x5gs.fsf@sdf.lonestar.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 205.166.94.20 X-Spam-Score: -2.3 (--) X-Debbugs-Envelope-To: submit X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -3.3 (---) --=-=-= Content-Type: text/plain Hello, Guix In developing a test suite for the internals of 'guix deploy', the virtual machine I spun up spat out an OpenSSH error that I've never encountered before. Jun 24 16:59:26 localhost sshd[235]: error: no more sessions This is, initially, quite curious. Creating the SSH session with #:log-verbosity set to 'protocol gives some insight. ;;; [2019/06/24 13:08:36.711847, 2] channel_open: Creating a channel 43 with 64000 window and 32768 max packet ;;; [2019/06/24 13:08:36.711959, 2] ssh_packet_global_request: Received SSH_MSG_GLOBAL_REQUEST packet ;;; [2019/06/24 13:08:36.711987, 2] ssh_packet_global_request: UNKNOWN SSH_MSG_GLOBAL_REQUEST hostkeys-00@openssh.com 0 ;;; [2019/06/24 13:08:36.712010, 1] ssh_packet_process: Couldn't do anything with packet type 80 ;;; [2019/06/24 13:08:36.712197, 2] ssh_packet_channel_open_conf: Received a CHANNEL_OPEN_CONFIRMATION for channel 43:0 ;;; [2019/06/24 13:08:36.712219, 2] ssh_packet_channel_open_conf: Remote window : 0, maxpacket : 32768 ;;; [2019/06/24 13:08:36.712618, 2] channel_rcv_change_window: Adding 2097152 bytes to channel (43:0) (from 0 bytes) ;;; [2019/06/24 13:08:36.712651, 2] channel_request: Channel request exec success ... ;;; [2019/06/24 12:59:26.296022, 2] channel_open: Creating a channel 74 with 64000 window and 32768 max packet ;;; [2019/06/24 12:59:26.296262, 2] ssh_packet_channel_open_conf: Received a CHANNEL_OPEN_CONFIRMATION for channel 74:8 ;;; [2019/06/24 12:59:26.296308, 2] ssh_packet_channel_open_conf: Remote window : 0, maxpacket : 32768 ;;; [2019/06/24 12:59:26.296667, 2] channel_rcv_change_window: Adding 2097152 bytes to channel (74:8) (from 0 bytes) ;;; [2019/06/24 12:59:26.296721, 2] channel_request: Channel request exec success ;;; [2019/06/24 12:59:26.487339, 2] grow_window: growing window (channel 74:8) to 1280000 bytes ;;; [2019/06/24 12:59:26.489031, 2] channel_open: Creating a channel 75 with 64000 window and 32768 max packet ;;; [2019/06/24 12:59:26.489376, 2] ssh_packet_channel_open_conf: Received a CHANNEL_OPEN_CONFIRMATION for channel 75:8 ;;; [2019/06/24 12:59:26.489402, 2] ssh_packet_channel_open_conf: Remote window : 0, maxpacket : 32768 ;;; [2019/06/24 12:59:26.489858, 2] channel_rcv_change_window: Adding 2097152 bytes to channel (75:8) (from 0 bytes) ;;; [2019/06/24 12:59:26.489906, 2] channel_request: Channel request exec success ;;; [2019/06/24 12:59:26.542586, 2] grow_window: growing window (channel 75:8) to 1280000 bytes ;;; [2019/06/24 12:59:26.546104, 2] channel_open: Creating a channel 76 with 64000 window and 32768 max packet ;;; [2019/06/24 12:59:26.546407, 2] ssh_packet_channel_open_conf: Received a CHANNEL_OPEN_CONFIRMATION for channel 76:9 ;;; [2019/06/24 12:59:26.546438, 2] ssh_packet_channel_open_conf: Remote window : 0, maxpacket : 32768 ;;; [2019/06/24 12:59:26.546839, 2] channel_rcv_change_window: Adding 2097152 bytes to channel (76:9) (from 0 bytes) ;;; [2019/06/24 12:59:26.546865, 2] channel_request: Channel request exec success ;;; [2019/06/24 12:59:26.630055, 2] grow_window: growing window (channel 76:9) to 1280000 bytes ;;; [2019/06/24 12:59:27.272139, 2] channel_open: Creating a channel 77 with 64000 window and 32768 max packet ;;; [2019/06/24 12:59:27.272846, 1] ssh_packet_channel_open_fail: Channel opening failure: channel 77 error (2) open failed I will admit that my knowledge of the SSH protocol is limited, but the rising channel number gives me the impression that channels are going out of scope and aren't being cleaned up. For reference, this occurs when 'remote-eval' is invoked multiple times -- which, in turn, invokes 'send-files'. building path(s) `/gnu/store/3rfkwdbayg7m3wdrydmcljnfqhvrady5-remote-exp.scm' sending 1 store item (0 MiB) to 'localhost'... exporting path `/gnu/store/3rfkwdbayg7m3wdrydmcljnfqhvrady5-remote-exp.scm' building path(s) `/gnu/store/ib59b0pnypsw4vf59f2gwpwhn343xnzb-remote-exp.scm' sending 1 store item (0 MiB) to 'localhost'... exporting path `/gnu/store/ib59b0pnypsw4vf59f2gwpwhn343xnzb-remote-exp.scm' [this is where the "no more sessions" error occurs] Currently, my code performs all of these 'remote-eval' calls with the same session. I suppose it would be possible to create a new session for each call, but I feel I should raise this as it may cause issues down the line: do we need to do something about cleaning up SSH channels? If a reproducible example is necessary, you can look to the temporary 'tests/machine.scm' in 64ffe453b0c71f417927737fa808dffe858359cd on my personal branch.[1] Regards, Jakob [1]: https://git.sr.ht/~jakob/guix/ --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEa1VJLOiXAjQ2BGSm9Qb9Fp2P2VoFAl0RBxMACgkQ9Qb9Fp2P 2VrvcxAApJkJljMn9BObHClrw8V+oOnNn2xO8qrcqRZQEPxBiJYVRWj3fLg18ozE S9ePPsmWe+UvVSg8wszOydt4RVejJVKaGg1OZYY5tLznMiVQU6k65lQN1jpzkOr1 pgenJZNE0SqgL9rkV/4kHiBf/S97T3kBKYn9VU+1Sh2KPOLqOtCisiqICY5sfTBY /R+ZHn9Ijo2tMX1XoDWSpsA4VxdwhS0Y8Oqab/7MjiqoCr3TgY05tzYEZ88JCfQ/ V9ljl3FKMXhFd8tLKDKoM0q+FNfF18G6+HtPHPnlLn4Anh3hKBry/Y4WycPBziNz wp3iydtLQrDMYMKBjD9fQ0nH7NQGBbGpyY02IZLwF+LL+Fjschl9VXRYIZMz15iG HcX9lFy660bLEbyvXnnaL5bJGhAVHiejeu6F069L3s4t9U4NiKXs8tNpRDrHKmRm K2wgm55hWZDGM0LCyjRXl++iPY8lVlIo/NOQqEF4GH3+DxnSF+LXYYUJka9lz5Cn 8qrmiQzHjQBuvfmA2L+3MOe1tmphe++bKiewZKS/EcDwx02W5wWq+yXrngM+JE+R 5ajkHe+HvewLDj55RQyMu5byPWR72m1Bdyd4yb3732Qmm+C/0R7ggsQrhObakAJT Ojg8G9VRg2xMLYbZ7ukzm+bfYEDjsyqpUtRQm4bwAKvqrB++cH4= =Ldje -----END PGP SIGNATURE----- --=-=-=-- From debbugs-submit-bounces@debbugs.gnu.org Mon Jun 24 16:45:49 2019 Received: (at 36364) by debbugs.gnu.org; 24 Jun 2019 20:45:49 +0000 Received: from localhost ([127.0.0.1]:58150 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hfVqX-00048N-1C for submit@debbugs.gnu.org; Mon, 24 Jun 2019 16:45:49 -0400 Received: from eggs.gnu.org ([209.51.188.92]:60708) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hfVqR-000486-GL for 36364@debbugs.gnu.org; Mon, 24 Jun 2019 16:45:45 -0400 Received: from fencepost.gnu.org ([2001:470:142:3::e]:43956) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hfVqK-0003XT-DL; Mon, 24 Jun 2019 16:45:38 -0400 Received: from [2a01:e0a:1d:7270:af76:b9b:ca24:c465] (port=43900 helo=ribbon) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1hfVqI-0001gB-Vj; Mon, 24 Jun 2019 16:45:35 -0400 From: =?utf-8?Q?Ludovic_Court=C3=A8s?= To: zerodaysfordays@sdf.lonestar.org (Jakob L. Kreuze) Subject: Re: bug#36364: Potential SSH session exhaustion References: <87pnn2x5gs.fsf@sdf.lonestar.org> X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 6 Messidor an 227 de la =?utf-8?Q?R=C3=A9volution?= X-PGP-Key-ID: 0x090B11993D9AEBB5 X-PGP-Key: http://www.fdn.fr/~lcourtes/ludovic.asc X-PGP-Fingerprint: 3CE4 6455 8A84 FDC6 9DB4 0CFB 090B 1199 3D9A EBB5 X-OS: x86_64-pc-linux-gnu Date: Mon, 24 Jun 2019 22:45:33 +0200 In-Reply-To: <87pnn2x5gs.fsf@sdf.lonestar.org> (Jakob L. Kreuze's message of "Mon, 24 Jun 2019 13:23:31 -0400") Message-ID: <87ftny3e6q.fsf@gnu.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="=-=-=" X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Spam-Score: -2.3 (--) X-Debbugs-Envelope-To: 36364 Cc: 36364@debbugs.gnu.org X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -3.3 (---) --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Hello Jakob, zerodaysfordays@sdf.lonestar.org (Jakob L. Kreuze) skribis: > In developing a test suite for the internals of 'guix deploy', the > virtual machine I spun up spat out an OpenSSH error that I've never > encountered before. > > Jun 24 16:59:26 localhost sshd[235]: error: no more sessions > > This is, initially, quite curious. Creating the SSH session with > #:log-verbosity set to 'protocol gives some insight. [...] > ;;; [2019/06/24 12:59:26.546104, 2] channel_open: Creating a channel 76= with 64000 window and 32768 max packet > ;;; [2019/06/24 12:59:26.546407, 2] ssh_packet_channel_open_conf: Recei= ved a CHANNEL_OPEN_CONFIRMATION for channel 76:9 > ;;; [2019/06/24 12:59:26.546438, 2] ssh_packet_channel_open_conf: Remot= e window : 0, maxpacket : 32768 > ;;; [2019/06/24 12:59:26.546839, 2] channel_rcv_change_window: Adding 2= 097152 bytes to channel (76:9) (from 0 bytes) > ;;; [2019/06/24 12:59:26.546865, 2] channel_request: Channel request ex= ec success > ;;; [2019/06/24 12:59:26.630055, 2] grow_window: growing window (channe= l 76:9) to 1280000 bytes > ;;; [2019/06/24 12:59:27.272139, 2] channel_open: Creating a channel 77= with 64000 window and 32768 max packet > ;;; [2019/06/24 12:59:27.272846, 1] ssh_packet_channel_open_fail: Chann= el opening failure: channel 77 error (2) open failed > > I will admit that my knowledge of the SSH protocol is limited, but the > rising channel number gives me the impression that channels are going > out of scope and aren't being cleaned up. Procedures like =E2=80=98send-files=E2=80=99 call =E2=80=98channel-get-exit= -status=E2=80=99 and =E2=80=98close-port=E2=80=99 on ports that represent SSH channels. AFAICS, =E2=80=98close-port=E2=80=99 triggers a call of =E2=80=98ptob_close= =E2=80=99 in Guile-SSH, which in turn calls =E2=80=98ssh_channel_close=E2=80=99. sshd_config(5) says: --8<---------------cut here---------------start------------->8--- MaxSessions Specifies the maximum number of open shell, login or subsystem (e.g. sftp) sessions permitted per network connection. Multiple sessions may be established by clients that support connection multiplexing. Setting MaxSessions to 1 will effectively disable session multiplexing, whereas setting it to 0 will prevent all shell, login and subsystem sessions while still permitting forwarding. The default is 10. --8<---------------cut here---------------end--------------->8--- So you must be hitting this limit. I see that =E2=80=98remote-eval=E2=80=99 does not close =E2=80=98remote=E2= =80=99 though, so this channel port remains open until it=E2=80=99s GC=E2=80=99d, which happens too late. = Could you try the attached patch? It allows me to do more than 10 =E2=80=98remote-ev= al=E2=80=99 calls in a row. Thanks, Ludo=E2=80=99. --=-=-= Content-Type: text/x-patch Content-Disposition: inline diff --git a/guix/remote.scm b/guix/remote.scm index cc051dee8a..fa19ece112 100644 --- a/guix/remote.scm +++ b/guix/remote.scm @@ -116,6 +116,7 @@ remote store." (mbegin %store-monad (built-derivations to-build) ((store-lift send-files) to-send remote #:recursive? #t) + (return (close-connection remote)) (return (%remote-eval lowered session)))) (let ((to-send (map (lambda (input) (match (gexp-input-thing input) @@ -127,4 +128,5 @@ remote store." (mbegin %store-monad ((store-lift send-files) to-send remote #:recursive? #t) (return (build-derivations remote to-build)) + (return (close-connection remote)) (return (%remote-eval lowered session))))))) --=-=-=-- From debbugs-submit-bounces@debbugs.gnu.org Mon Jun 24 19:30:01 2019 Received: (at 36364) by debbugs.gnu.org; 24 Jun 2019 23:30:02 +0000 Received: from localhost ([127.0.0.1]:58358 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hfYPR-0006Un-KW for submit@debbugs.gnu.org; Mon, 24 Jun 2019 19:30:01 -0400 Received: from ol.sdf.org ([205.166.94.20]:57143 helo=mx.sdf.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hfYPO-0006Ud-TY for 36364@debbugs.gnu.org; Mon, 24 Jun 2019 19:30:00 -0400 Received: from Epsilon (pool-173-76-53-40.bstnma.fios.verizon.net [173.76.53.40]) (authenticated (0 bits)) by mx.sdf.org (8.15.2/8.14.5) with ESMTPSA id x5ONTtm0002156 (using TLSv1.2 with cipher AES256-GCM-SHA384 (256 bits) verified NO); Mon, 24 Jun 2019 23:29:56 GMT From: zerodaysfordays@sdf.lonestar.org (Jakob L. Kreuze) To: Ludovic =?utf-8?Q?Court=C3=A8s?= Subject: Re: bug#36364: Potential SSH session exhaustion In-Reply-To: <87ftny3e6q.fsf@gnu.org> ("Ludovic \=\?utf-8\?Q\?Court\=C3\=A8s\=22'\?\= \=\?utf-8\?Q\?s\?\= message of "Mon, 24 Jun 2019 22:45:33 +0200") References: <87pnn2x5gs.fsf@sdf.lonestar.org> <87ftny3e6q.fsf@gnu.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) Date: Mon, 24 Jun 2019 19:28:28 -0400 Message-ID: <877e9awokj.fsf@sdf.lonestar.org> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" X-Spam-Score: 0.0 (/) X-Debbugs-Envelope-To: 36364 Cc: 36364@debbugs.gnu.org X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -1.0 (-) --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Hi, Ludovic Court=C3=A8s writes: > Procedures like =E2=80=98send-files=E2=80=99 call =E2=80=98channel-get-ex= it-status=E2=80=99 and > =E2=80=98close-port=E2=80=99 on ports that represent SSH channels. > > AFAICS, =E2=80=98close-port=E2=80=99 triggers a call of =E2=80=98ptob_clo= se=E2=80=99 in Guile-SSH, > which in turn calls =E2=80=98ssh_channel_close=E2=80=99. > > sshd_config(5) says: > > MaxSessions Specifies the maximum number of open shell, login or subsy= stem > (e.g. sftp) sessions permitted per network connection. Multiple sessions = may be > established by clients that support connection multiplexing. Setting MaxS= essions > to 1 will effectively disable session multiplexing, whereas setting it to= 0 will > prevent all shell, login and subsystem sessions while still permitting > forwarding. The default is 10. > > So you must be hitting this limit. Ah, thank you for the corrections :) > I see that =E2=80=98remote-eval=E2=80=99 does not close =E2=80=98remote= =E2=80=99 though, so this > channel port remains open until it=E2=80=99s GC=E2=80=99d, which happens = too late. > Could you try the attached patch? It allows me to do more than 10 > =E2=80=98remote-eval=E2=80=99 calls in a row. Wow, that was quick. The patch works like a charm, thanks! Regards, Jakob --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEa1VJLOiXAjQ2BGSm9Qb9Fp2P2VoFAl0RXJ0ACgkQ9Qb9Fp2P 2Vpwfw/6Awi/sdKYTZLbLwfydvRUMXMK68YpdFxAzNCf7spd0Ayv5nGblKqXRWOz ATDXea+fNpFmgbKF1KVztCrWqxCS8ySyujlQlC+ETGbyygvjlhFpJg6HmYyW/S+R 4v78zxWUHgVNT/rVdpKToJQd2037PlvHGJBAYFuT9YOAeJ61NcCL6MMP/2eHO3fi JhgkFEJiv51Cu06zLXzpKFHh1zUXYXjs9hpVBD+HwYU9pM5GKB73+crx9Np0qF/w 975l1QqIA5hJgDfZQLXilQ1a9YBuL2ev28N6WoUnMeWQ3/zyEGQc4a6gAWoxYXtY DVOMs3iiSU85FKcHFJKowkWP6n7qNSwJWWg3oLJojeUApOc/TdnOWKGcc/1dP8bF HxV8Rysp2YPVS7kw/G9uctHjqz620j09oX8fhA5afc6EKUAQydHv2MjsfwoQYWPB obt9xOCVd93xB962d7CrXIeIWBue8EKc9qwkladCwsu9ik+dm36Ltm2MWUa5Zd+Z N+A0ScIv17G50wMn3IVacCrupPwF3r0rE5FOHxC35sChb8NjjG9/R4n9cIWEzAUu 1x7ACDPQK6vrmkNFSSWiuK4PnLl2yC23SzAvmmDLBF2caqRM6Cx2ft45o6SNzxJC M2Dlqc+rTWYOw7FUhTQY69fiQOl/gPDRI8rCTxzJQYqMV7rCY0I= =mzRr -----END PGP SIGNATURE----- --=-=-=-- From debbugs-submit-bounces@debbugs.gnu.org Tue Jun 25 12:14:34 2019 Received: (at 36364-done) by debbugs.gnu.org; 25 Jun 2019 16:14:34 +0000 Received: from localhost ([127.0.0.1]:33366 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hfo5Z-0003g5-UV for submit@debbugs.gnu.org; Tue, 25 Jun 2019 12:14:34 -0400 Received: from eggs.gnu.org ([209.51.188.92]:37792) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hfo5U-0003fj-EJ for 36364-done@debbugs.gnu.org; Tue, 25 Jun 2019 12:14:32 -0400 Received: from fencepost.gnu.org ([2001:470:142:3::e]:60950) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hfo5N-0006FU-Cc; Tue, 25 Jun 2019 12:14:21 -0400 Received: from [2001:660:6102:320:e120:2c8f:8909:cdfe] (port=53748 helo=ribbon) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1hfo5L-00076N-L9; Tue, 25 Jun 2019 12:14:20 -0400 From: =?utf-8?Q?Ludovic_Court=C3=A8s?= To: zerodaysfordays@sdf.lonestar.org (Jakob L. Kreuze) Subject: Re: bug#36364: Potential SSH session exhaustion References: <87pnn2x5gs.fsf@sdf.lonestar.org> <87ftny3e6q.fsf@gnu.org> <877e9awokj.fsf@sdf.lonestar.org> Date: Tue, 25 Jun 2019 18:14:16 +0200 In-Reply-To: <877e9awokj.fsf@sdf.lonestar.org> (Jakob L. Kreuze's message of "Mon, 24 Jun 2019 19:28:28 -0400") Message-ID: <87y31pk5gn.fsf@gnu.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Spam-Score: -2.3 (--) X-Debbugs-Envelope-To: 36364-done Cc: 36364-done@debbugs.gnu.org X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -3.3 (---) Hi, zerodaysfordays@sdf.lonestar.org (Jakob L. Kreuze) skribis: > Ludovic Court=C3=A8s writes: [...] >> I see that =E2=80=98remote-eval=E2=80=99 does not close =E2=80=98remote= =E2=80=99 though, so this >> channel port remains open until it=E2=80=99s GC=E2=80=99d, which happens= too late. >> Could you try the attached patch? It allows me to do more than 10 >> =E2=80=98remote-eval=E2=80=99 calls in a row. > > Wow, that was quick. The patch works like a charm, thanks! Cool, thanks for testing! (I plan to merge the =E2=80=98remove-eval=E2=80=99 patches soonish=E2=80=A6) Ludo=E2=80=99. From unknown Sat Aug 16 12:44:33 2025 Received: (at fakecontrol) by fakecontrolmessage; To: internal_control@debbugs.gnu.org From: Debbugs Internal Request Subject: Internal Control Message-Id: bug archived. Date: Wed, 24 Jul 2019 11:24:09 +0000 User-Agent: Fakemail v42.6.9 # This is a fake control message. # # The action: # bug archived. thanks # This fakemail brought to you by your local debbugs # administrator