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=1793214655; b=5DnOasqckfM4NkXoVDG0qQb+hD44KeiqGjpfYn/ixaY+xT82ng/3XXYPwEy5bRBUfGE7 73/OYblmp+SWcjIljH0UnEUYeExFNaL4BLAEImOBldassNHLsIhOXeBBnm0Kud8qOpsEb nox/8x6oKbUfgLtBiG7VjDu3n1di8qDW297EFAAEY0ULTNc00uUCEiAWAhXt/1XHj9B94 kgxPY/JUPoL0K9HlJndWuV/8Is/DZXBpZxWRrgaeOAgtQYHxyUaYtb9JJfuJinUBOcvE9 Wwzj92/mVMDEpUvi/xn9rV1+4Qtj5cvhiVerKVBJ/Upj8fOs1C67/uAGlzEXGacFniA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793214655; 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=3Pf36+kstbtfoRyGtpUyHnXVSWJ/oyF1xDL45XANKvM=; b=rufFtuU/8BbNDYUh+R0/nkC9pU8AC2tJhcXWbIvdotIVhxSJLDCgTyjnev79BBgFXpq/ PTAkIuqEoKZrxEGOif6j95veuSRNfTwZ9jr3ot5hTbJZyg0+QM2DjqImtbVM+WWMgc3Xl BWwTjZNfpogU+Iz8IcYUvO0CYdUf4mp/+RkvtNISr98Jlfp48KRoMMYIRiNacnaWdu7/A R0p17QvLRCsWMluwqC0N7xFMbxYH4KAGEmX9hnMV/dQUAjn9ru+BvfGV+8zvdbW8okK0C Wvq32kFwnfGRCKni5SGH8Y5I8xb8DxH5hULVHmlKdvOlbj7kNBkCKHXLXZYUOUIm8lw== 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=t8fpQR6Q; 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 0FB59606A31F; Wed, 28 Oct 2026 19:10:55 +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=t8fpQR6Q Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60B701F01825; Wed, 28 Oct 2026 19:10:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793214654; bh=3Pf36+kstbtfoRyGtpUyHnXVSWJ/oyF1xDL45XANKvM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=t8fpQR6Q6sgzu3C4HKMtm12ilnGvSjoQvva7LY4UOjHdtJ8AIsW+F8iU0W+jPyPO2 0QCroNSSXJ2r1WnWY31KAUdXFHSgHgYzool5yqlHAYCFNJiuBKMk2n8cVRiLmex0I0 Nq8bWRxmr9SOg616BHEqOeqE6upuGgaQPhzYkX8o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Igor Stepansky , Namjae Jeon , Steve French , Sasha Levin Subject: [PATCH 6.1 0934/1887] ksmbd: add chann_lock to protect ksmbd_chann_list xarray Date: Wed, 28 Oct 2026 17:50:30 +0100 Message-ID: <20261028170520.667447497@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170459.200466217@linuxfoundation.org> References: <20261028170459.200466217@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 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Namjae Jeon [ Upstream commit 4f3a06cc57976cafa8c6f716646be6c79a99e485 ] ksmbd_chann_list xarray lacks synchronization, allowing use-after-free in multi-channel sessions (between lookup_chann_list() and ksmbd_chann_del). Adds rw_semaphore chann_lock to struct ksmbd_session and protects all xa_load/xa_store/xa_erase accesses. Cc: stable@vger.kernel.org Reported-by: Igor Stepansky Signed-off-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Sasha Levin --- fs/smb/server/mgmt/user_session.c | 5 +++++ fs/smb/server/mgmt/user_session.h | 1 + fs/smb/server/smb2pdu.c | 12 +++++++++++- 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/fs/smb/server/mgmt/user_session.c b/fs/smb/server/mgmt/user_session.c index 605e17c7b2a17..33ae100fd07ed 100644 --- a/fs/smb/server/mgmt/user_session.c +++ b/fs/smb/server/mgmt/user_session.c @@ -32,12 +32,14 @@ static void free_channel_list(struct ksmbd_session *sess) struct channel *chann; unsigned long index; + down_write(&sess->chann_lock); xa_for_each(&sess->ksmbd_chann_list, index, chann) { xa_erase(&sess->ksmbd_chann_list, index); kfree(chann); } xa_destroy(&sess->ksmbd_chann_list); + up_write(&sess->chann_lock); } static void __session_rpc_close(struct ksmbd_session *sess, @@ -220,7 +222,9 @@ static int ksmbd_chann_del(struct ksmbd_conn *conn, struct ksmbd_session *sess) { struct channel *chann; + down_write(&sess->chann_lock); chann = xa_erase(&sess->ksmbd_chann_list, (long)conn); + up_write(&sess->chann_lock); if (!chann) return -ENOENT; @@ -422,6 +426,7 @@ static struct ksmbd_session *__session_create(int protocol) rwlock_init(&sess->tree_conns_lock); atomic_set(&sess->refcnt, 2); init_rwsem(&sess->rpc_lock); + init_rwsem(&sess->chann_lock); ret = __init_smb2_session(sess); if (ret) diff --git a/fs/smb/server/mgmt/user_session.h b/fs/smb/server/mgmt/user_session.h index 011362e975b00..90ae30ba402f4 100644 --- a/fs/smb/server/mgmt/user_session.h +++ b/fs/smb/server/mgmt/user_session.h @@ -49,6 +49,7 @@ struct ksmbd_session { char sess_key[CIFS_KEY_SIZE]; struct hlist_node hlist; + struct rw_semaphore chann_lock; struct xarray ksmbd_chann_list; struct xarray tree_conns; struct ida tree_conn_ida; diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 16477ad9dde8d..b05a9488aaa4d 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -78,7 +78,13 @@ static inline bool check_session_id(struct ksmbd_conn *conn, u64 id) struct channel *lookup_chann_list(struct ksmbd_session *sess, struct ksmbd_conn *conn) { - return xa_load(&sess->ksmbd_chann_list, (long)conn); + struct channel *chann; + + down_read(&sess->chann_lock); + chann = xa_load(&sess->ksmbd_chann_list, (long)conn); + up_read(&sess->chann_lock); + + return chann; } /** @@ -1580,7 +1586,9 @@ static int ntlm_authenticate(struct ksmbd_work *work, return -ENOMEM; chann->conn = conn; + down_write(&sess->chann_lock); xa_store(&sess->ksmbd_chann_list, (long)conn, chann, GFP_KERNEL); + up_write(&sess->chann_lock); } } @@ -1673,7 +1681,9 @@ static int krb5_authenticate(struct ksmbd_work *work, return -ENOMEM; chann->conn = conn; + down_write(&sess->chann_lock); xa_store(&sess->ksmbd_chann_list, (long)conn, chann, GFP_KERNEL); + up_write(&sess->chann_lock); } } -- 2.53.0