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=1794061010; b=CBWj9abhhHLrbqA2SGB67fEbng0nhxF76CFhEb7wamShvru2Im5VebUO8YhjNweh9zXc L6GxQQLGoXmRVkxyN2JobGqGV7epElPaN/WZXQUmLDTvRBXTMzUtAZdxw80EQogbNtThd rLaNbcmUCKY3VkmbuE49UHiwd+lOB6zRZDbTG7Q321pF+OTJdhCEYVjUdtGRiVLTY+qq9 msGLMTB53qjMTfj2A/ENQA5bIPtCGbBsNtoFho7KHLGMLlkX4gtC9hSL0I2tBP7gEkCbh 8FVNvWfSt51lYb5r3MMBDHI2KiEUCI0m+3MyFo0YMKCJtMH84jLjpTwMM2lr+U+Zn5w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794061010; 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=rjEBcH0RnCBxDudztVP4w9J1j7R0hNp1A+wLJQSFoCQ=; b=hHDV30X+QIRb+ZsbNB4pYmpEudPU0dnncd5wUl++nvWWRuoHHFcN0CL6YxZT3783URqN Q6XrhIBWd0hsAMRdtvmnAtG8UFs9ZUZX2f9fk3JYvqa0dfQo4qNc0MCfo7qNSlMmWmwJs AOh2JipJid0qzHreshtuUzkGjZubpftej3CeoeVHrKYZKsM2tnXhs5s0smSvMVXtJ15o7 GHCK0ZI2RJmWRgbqb5E2QIZ83XPuYTMhTL5xmcIDXb7YkMyOJoibRBusZ4r73ibtEIJ16 4WfbIcEhgxFx7Eu30dpXj/ApX1PlVg+tqD8SVn/qUuR+oDP2MFXo80WG5oL97fYRhAQ== 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="evVT/+tP"; 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 8BDBD606D80E; Sat, 7 Nov 2026 14:16:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=evVT/+tP Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3866E1F008A1; Sat, 7 Nov 2026 14:16:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794061010; bh=rjEBcH0RnCBxDudztVP4w9J1j7R0hNp1A+wLJQSFoCQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=evVT/+tPDHysKU7JIjzPq4XdR1OCHFA7vbV/zujjZWSztev4oRD4x3xeKZ/TRtcTJ hZPQiwJ+wOvWcS+4jrvGmGqfU0QEQZNWjJH5B42F5IA7bnm7AgnJcDaXVsWpy3i0ss sEjtmiEwKq5hbwPuQWVfHCr5wy31Hn7+zyXQnZXY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Namjae Jeon , Sasha Levin Subject: [PATCH 6.12 0353/1536] ksmbd: reject blocking compound lock requests Date: Sat, 7 Nov 2026 08:39:29 -0500 Message-ID: <20261107135007.581500357@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134957.653319350@linuxfoundation.org> References: <20261107134957.653319350@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-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 e5d5a08022198..4bbff7f413003 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -7706,6 +7706,13 @@ 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