From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 685BF35BDDD; Wed, 3 Dec 2025 17:00:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764781246; cv=none; b=HMTf/g3txYl95ngmZDm61wlFvS11JptLThYLL6RbO2Xt2MIUbIA6XA0Am8jGxlbwtAm07o1DiPp0W0OWsu7ixZLJwSimMHdvbirjujZyZuVPAt4sG4qe2cmV0IM6f3llrVq6XnAKVn1OHNgImK41ALdg0emdObsyOO8E5X2pB2A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764781246; c=relaxed/simple; bh=7ojcJ8v1ZHLbDYnEUKqDnAWybzDjeh1J9hww2SbRyYk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iQgwLrFlkcwjnBzE6A7QnE+ZGEC8sKEPizCrMBOFUl5njBKP7Vdno/dFfMSLofFWaTD8zbnnjcKFw5WzAEyclcAvWKTcXRg0uEL+jPqtGmZAu9x4EI8hsyWa76fNNZ9nNJjOsLaN7HxmZh7vmjbsyhxX8KfO3I3z087AQeNc1cM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=0KOpjnCa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="0KOpjnCa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6C3FC4CEF5; Wed, 3 Dec 2025 17:00:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764781246; bh=7ojcJ8v1ZHLbDYnEUKqDnAWybzDjeh1J9hww2SbRyYk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0KOpjnCa9F74XgqpjN/7IwqMOfx51mki/2ndFCQkzYdGwQK6WuQZ3oBTcYSE8NT7n KSLybXpzAUh2iQgHJSLVljFeGgGM0NhtrsgKzKclR/Lw26KUNlbez9AOdKBeHSciBp DtjA8FVsRiiKnhf/5xAOv6f4hYoq9M2xGkJLZjo4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sean Heelan , Namjae Jeon , Steve French , Nazar Kalashnikov Subject: [PATCH 6.6 90/93] ksmbd: fix use-after-free in session logoff Date: Wed, 3 Dec 2025 16:30:23 +0100 Message-ID: <20251203152339.887030489@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251203152336.494201426@linuxfoundation.org> References: <20251203152336.494201426@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sean Heelan commit 2fc9feff45d92a92cd5f96487655d5be23fb7e2b upstream. The sess->user object can currently be in use by another thread, for example if another connection has sent a session setup request to bind to the session being free'd. The handler for that connection could be in the smb2_sess_setup function which makes use of sess->user. Signed-off-by: Sean Heelan Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Nazar Kalashnikov Signed-off-by: Greg Kroah-Hartman --- v2: Fix duplicate From: header Backport fix for CVE-2025-37899 fs/smb/server/smb2pdu.c | 4 ---- 1 file changed, 4 deletions(-) --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -2255,10 +2255,6 @@ int smb2_session_logoff(struct ksmbd_wor sess->state = SMB2_SESSION_EXPIRED; up_write(&conn->session_lock); - if (sess->user) { - ksmbd_free_user(sess->user); - sess->user = NULL; - } ksmbd_all_conn_set_status(sess_id, KSMBD_SESS_NEED_SETUP); rsp->StructureSize = cpu_to_le16(4);