fix: prevent int underflow in link write (#935)

jean-roland · web-flow · commit fe559a44b88b · 2025-04-07T17:18:19.000+08:00
diff --git a/src/link/link.c b/src/link/link.c
@@ -182,7 +182,7 @@ z_result_t _z_link_send_wbuf(const _z_link_t *link, const _z_wbuf_t *wbf, _z_sys
         size_t n = bs.len;
         do {
             size_t wb = link->_write_f(link, bs.start, n, socket);
-            if (wb == SIZE_MAX) {
+            if ((wb == SIZE_MAX) || (wb > n)) {
                 ret = _Z_ERR_TRANSPORT_TX_FAILED;
                 break;
             }

Original file line number	Diff line number	Diff line change
`@@ -182,7 +182,7 @@ z_result_t _z_link_send_wbuf(const _z_link_t link, const _z_wbuf_t wbf, _z_sys`
`182`	`182`	`size_t n = bs.len;`
`183`	`183`	`do {`
`184`	`184`	`size_t wb = link->_write_f(link, bs.start, n, socket);`
`185`		`- if (wb == SIZE_MAX) {`
	`185`	`+ if ((wb == SIZE_MAX) \|\| (wb > n)) {`
`186`	`186`	`ret = _Z_ERR_TRANSPORT_TX_FAILED;`
`187`	`187`	`break;`
`188`	`188`	`}`