From: Denis Arefev Date: Wed, 9 Apr 2025 09:04:49 +0000 (+0300) Subject: ksmbd: Prevent integer overflow in calculation of deadtime X-Git-Tag: v6.6.88~69 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=160935d81f2c577984cb684af8decb5090f73b28;p=thirdparty%2Fkernel%2Fstable.git ksmbd: Prevent integer overflow in calculation of deadtime commit a93ff742820f75bf8bb3fcf21d9f25ca6eb3d4c6 upstream. The user can set any value for 'deadtime'. This affects the arithmetic expression 'req->deadtime * SMB_ECHO_INTERVAL', which is subject to overflow. The added check makes the server behavior more predictable. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and tranport layers") Cc: stable@vger.kernel.org Signed-off-by: Denis Arefev Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/smb/server/transport_ipc.c b/fs/smb/server/transport_ipc.c index 2d7cd7f42f278..281101fd1f76f 100644 --- a/fs/smb/server/transport_ipc.c +++ b/fs/smb/server/transport_ipc.c @@ -296,7 +296,11 @@ static int ipc_server_config_on_startup(struct ksmbd_startup_request *req) server_conf.signing = req->signing; server_conf.tcp_port = req->tcp_port; server_conf.ipc_timeout = req->ipc_timeout * HZ; - server_conf.deadtime = req->deadtime * SMB_ECHO_INTERVAL; + if (check_mul_overflow(req->deadtime, SMB_ECHO_INTERVAL, + &server_conf.deadtime)) { + ret = -EINVAL; + goto out; + } server_conf.share_fake_fscaps = req->share_fake_fscaps; ksmbd_init_domain(req->sub_auth); @@ -322,6 +326,7 @@ static int ipc_server_config_on_startup(struct ksmbd_startup_request *req) ret |= ksmbd_set_work_group(req->work_group); ret |= ksmbd_tcp_set_interfaces(KSMBD_STARTUP_CONFIG_INTERFACES(req), req->ifc_list_sz); +out: if (ret) { pr_err("Server configuration error: %s %s %s\n", req->netbios_name, req->server_string,