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=1794590248; b=ft42ILVaplt+4VVEjMn4PIoPHg/NiXDfsxbE3umOrrLVfvpPaBJWodyR0N7X0JDKsho/ nPB1WYNUL+y6ZhK3cGXA6gFzAEMAjm2HJ/9Ev4YgWAb7g1cS8AjSfHjoKLOcRNHmdxLZ8 zZM6O93jQV9u6hVuWjNNS4KyGmerixnt7w0pNVOisyFcyCZYlD57uBMMxqRW9lhMEecwZ xHKrE1HFttB8QPKjYi/76oB2f2cubrMMjAcz8CMLDQIKHvcwRXv4rQsPkEm/m/Bweww/F 6hQs+yvnwJT69U8gePd8e3TUdJh7GJU3Jx6w3er25iHEXotm4PQOz4fw7MghrOaKMJQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794590248; 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=pyumZJgacJHFwOVJ0jxeLB5Qm3If35qC92LVdAZrM2Y=; b=BbFfusboUQq2zFpigWgF9Q1e+bk34rqZUg/wb55Vf+xIj+Jm1Ut32EDpi/i4JPptjdlX VodX2DivyZ36cG1L1z3rC450EXBDPIz1uY82AtLTowZbroZ+Bwb9Ie9OyU4onsVJJexWI xR1Y2S0bRipz+b/NuawxHDzigRKH+Tr64Pr2/acd+FDbH2wM7YaYdZLgyy6HYa/EMhP6P MDDXYTUkulDp4x2fOxIiqfpXdr3yRBHrNZxSitmnmIc6jPCiBrwsnIxOKNzIz2Bbo6VXO YhXDA108DGuzFlv41VTc4AqdAt8uUGfJsLI6ESGEa/T4DTlZnQDL+ysAJS87rQ6ef8w== 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=eif3hrBD; 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 2D7AC60A2636; Fri, 13 Nov 2026 17:17:28 +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=eif3hrBD Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD6771F000C6; Fri, 13 Nov 2026 17:17:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794590248; bh=pyumZJgacJHFwOVJ0jxeLB5Qm3If35qC92LVdAZrM2Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=eif3hrBDr2Bjspm2P912k2yo2K/2Xqi/wrXdXpsRVfZI1RBuK8/RydbTSEfaSVwfY KF1O1FWsB/2+M4k97fkYXMfM+CxC9Qh8b5gI50gVNMgzoZtExqXQs2oQgUYtHjnFcs P+BsXCzXBXAWLVrUEKBJ+M8j1TC3lETTS0cWwWWo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Namjae Jeon , Ian Bridges , Sasha Levin Subject: [PATCH 6.18 245/686] ksmbd: grant a POSIX ACL group entry only to the groups members Date: Fri, 13 Nov 2026 10:46:18 -0500 Message-ID: <20261113153829.356260335@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153820.902362109@linuxfoundation.org> References: <20261113153820.902362109@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: Ian Bridges [ Upstream commit c00ec7ad449b68c291a4986e481941302ed399c5 ] When no ACE of the DACL matches the caller, Everyone or Authenticated Users, smb_check_perm_dacl() falls back to the file's POSIX ACL. It takes the first ACL_USER or ACL_GROUP entry whose id equals the caller's uid. For ACL_GROUP, this compares a gid with the caller's uid. A numerical match grants the group's permissions even when the caller is not a member. Match a group entry only when the caller is also in the group. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Reported-by: Namjae Jeon Closes: https://lore.kernel.org/linux-cifs/CAKYAXd93czbFD=znZUq_pJLXzDR5N3zc_auvAGWT7pzKR1f9Ag@mail.gmail.com/ Cc: stable@vger.kernel.org Signed-off-by: Ian Bridges Signed-off-by: Namjae Jeon Signed-off-by: Sasha Levin --- fs/smb/server/smbacl.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/smb/server/smbacl.c b/fs/smb/server/smbacl.c index 33a607e709f18..63f7bccb4d9af 100644 --- a/fs/smb/server/smbacl.c +++ b/fs/smb/server/smbacl.c @@ -1606,7 +1606,10 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, const struct path *path, else continue; - if (id == uid) { + /* A group entry grants only to the group's members */ + if (id == uid && + (pa_entry->e_tag == ACL_USER || + in_group_p(make_kgid(&init_user_ns, id)))) { mode_to_access_flags(pa_entry->e_perm, 0777, &access_bits); -- 2.53.0