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=1793830953; b=vsuDGyx2Ppd7g3WX1SwzeVoX4cWFd81KhzKQaaXKK8eB/qiHftM7gBCzF+zvKtYUSWkW CtiNR5KqGoc3Y+c7i/SD86d7meRJX9JBwCoGIkzeaxjjHZlvoIUBrb0/Tr0Em/ixzvr2f ScJeo2tNwbEOyTHY4cofcx1j2L7H8ZcTXnOK57k+iSJGaTYUkXUOtEd8NRXCrmluqTVIT iiLZoal8uesuWO3P5p6h/AcMq1FOT0+dbr0gF7h3X8GvH75y60vi/0QpAL6UTY0TzZFF6 m9nX6x3M4+xpRBeoJmRSOpCSyNTAi1Mwe98X85qyqWIQBPOX92e6HMam1RyL25n60yw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793830953; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=PvABLrsC2PZezqlr/htZCkEnlvOgM2Z5j5PTVY/LTBM=; b=wwqOqxB+N7bEPCs+NRbw/3VWpWTSakZvzFMxSMp+YQ+FUTH/YYA+1SKzujTVc9F99J3r vF7VBS4G+ZiraX+oIWy/bBqmZjf15vAuxudHnr8UQvahJ9+JVNO93swelKheFv6gayelY ngyIulEuf+fm1QTo+ievvmDN+68OWmXmzzRIYVB+ptI+ZJtWFUy7OBdhmokSi+nvkli6w i9RxQ6dS2j9VrMQ8mr+/c63A/PMgRURmHqWJxZHPstuUU/77r2XF7V0c6w2jeUl1phsOM DyNh+usxqITyKmV171JRJ2WoQgBaXvCbRv3LyzpAdhJNfR2uzrEq1maTDSvTQaY8YbA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="nM/8yTed"; 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 7F7BA606A844; Wed, 4 Nov 2026 22:22:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=nM/8yTed Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1827D1F000C1; Wed, 4 Nov 2026 22:22:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793830953; bh=PvABLrsC2PZezqlr/htZCkEnlvOgM2Z5j5PTVY/LTBM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nM/8yTeda6swLCz75LZfRXGPry/NgP1Gw2sLldaegmjhEdmuESgcZZBlHuc1Bb67W whKyrJyCct2sydIvGPLxhNU0vsLFt2ESE7Qn2JUr3/fviKL1Bgy2qpbCyKHSeMCA+3 rZshnEePZXJq3hfRww/DC2Vx4JvlHcbeup0Brp0U= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Namjae Jeon , Sasha Levin Subject: [PATCH 6.18 0419/1005] ksmbd: reject blocking compound lock requests Date: Wed, 4 Nov 2026 16:02:32 -0500 Message-ID: <20261104211055.833284573@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211043.516122098@linuxfoundation.org> References: <20261104211043.516122098@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Namjae Jeon [ Upstream commit 16a7f7c2ecf3c893b65f0fb78fa7a7171ae0ba9e ] Clients set SMB2_LOCKFLAG_FAIL_IMMEDIATELY when a LOCK request contains multiple lock elements, and servers reject requests that omit it. Accepting such a request can leave earlier elements locked while a later element waits asynchronously, enabling prolonged partial lock ownership and avoidable deadlocks. Return STATUS_INVALID_PARAMETER before processing any element when a multi-element lock request contains a blocking lock. Unlock arrays remain unaffected. Signed-off-by: Namjae Jeon Signed-off-by: Sasha Levin --- fs/smb/server/smb2pdu.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index edbac6c9b577c..40d7e3b6ed7e1 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -7753,6 +7753,13 @@ int smb2_lock(struct ksmbd_work *work) } list_for_each_entry_safe(smb_lock, tmp, &lock_list, llist) { + if (lock_count > 1 && + !(le32_to_cpu(lock_ele[0].Flags) & SMB2_LOCKFLAG_UNLOCK) && + !(smb_lock->flags & SMB2_LOCKFLAG_FAIL_IMMEDIATELY)) { + err = -EINVAL; + goto out; + } + if (smb_lock->cmd < 0) { err = -EINVAL; goto out; -- 2.53.0