[{"id":3678436,"web_url":"http://patchwork.ozlabs.org/comment/3678436/","msgid":"","list_archive_url":null,"date":"2026-04-16T23:36:44","subject":"Re: [PATCH] smb: server: fix max_connections off-by-one in tcp accept\n path","submitter":{"id":79386,"url":"http://patchwork.ozlabs.org/api/people/79386/","name":"Namjae Jeon","email":"linkinjeon@kernel.org"},"content":"On Fri, Apr 17, 2026 at 6:17 AM DaeMyung Kang wrote:\n>\n> The global max_connections check in ksmbd's TCP accept path counts\n> the newly accepted connection with atomic_inc_return(), but then\n> rejects the connection when the result is greater than or equal to\n> server_conf.max_connections.\n>\n> That makes the effective limit one smaller than configured. For\n> example:\n>\n> - max_connections=1 rejects the first connection\n> - max_connections=2 allows only one connection\n>\n> The per-IP limit in the same function uses <= correctly because it\n> counts only pre-existing connections. The global limit instead checks\n> the post-increment total, so it should reject only when that total\n> exceeds the configured maximum.\n>\n> Fix this by changing the comparison from >= to >, so exactly\n> max_connections simultaneous connections are allowed and the next one\n> is rejected. This matches the documented meaning of max_connections\n> in fs/smb/server/ksmbd_netlink.h as the \"Number of maximum simultaneous\n> connections\".\n>\n> Fixes: 0d0d4680db22 (\"ksmbd: add max connections parameter\")\n> Cc: stable@vger.kernel.org\n> Signed-off-by: DaeMyung Kang \nApplied it to #ksmbd-for-next-next.\nThanks!","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-cifs@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256\n header.s=k20201202 header.b=nHSY6H4H;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c04:e001:36c::12fc:5321; helo=tor.lore.kernel.org;\n envelope-from=linux-cifs+bounces-10880-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org\n header.b=\"nHSY6H4H\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=10.30.226.201"],"Received":["from tor.lore.kernel.org (tor.lore.kernel.org\n [IPv6:2600:3c04:e001:36c::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fxZFK0pr1z1yDF\n\tfor ; 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Thu, 16 Apr 2026\n 16:36:56 -0700 (PDT)","Precedence":"bulk","X-Mailing-List":"linux-cifs@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","References":"<20260416211735.3558718-1-charsyam@gmail.com>","In-Reply-To":"<20260416211735.3558718-1-charsyam@gmail.com>","From":"Namjae Jeon ","Date":"Fri, 17 Apr 2026 08:36:44 +0900","X-Gmail-Original-Message-ID":"\n ","X-Gm-Features":"AQROBzB66y9CrUgy1WHZWYxRh_RXy7Qc-7PMcqfpOvkbqt64rMF7nxAIdWWdei4","Message-ID":"\n ","Subject":"Re: [PATCH] smb: server: fix max_connections off-by-one in tcp accept\n path","To":"DaeMyung Kang ","Cc":"Steve French ,\n Sergey Senozhatsky ,\n\tTom Talpey , linux-cifs@vger.kernel.org,\n linux-kernel@vger.kernel.org,\n\tstable@vger.kernel.org","Content-Type":"text/plain; charset=\"UTF-8\"","Content-Transfer-Encoding":"quoted-printable"}}]