reboot.c: limit printing of the fourth argument to 255 bytes

esyr · ldv-alt · commit 395c90f71ccf · 2018-01-11T15:54:33.000Z
The size of kernel buffer is 256 bytes and the last byte is always zero.

* reboot.c (SYS_FUNC(reboot)): Replace printstr call with printstr_ex
with size of 255 and style flag QUOTE_0_TERMINATED.
diff --git a/reboot.c b/reboot.c
@@ -17,7 +17,12 @@ SYS_FUNC(reboot)
 	printxval(bootflags3, cmd, "LINUX_REBOOT_CMD_???");
 	if (cmd == LINUX_REBOOT_CMD_RESTART2) {
 		tprints(", ");
-		printstr(tcp, tcp->u_arg[3]);
+		/*
+		 * The size of kernel buffer is 256 bytes and
+		 * the last byte is always zero, at most 255 bytes
+		 * are copied from the user space.
+		 */
+		printstr_ex(tcp, tcp->u_arg[3], 255, QUOTE_0_TERMINATED);
 	}
 	return RVAL_DECODED;
 }

Original file line number	Diff line number	Diff line change
`@@ -17,7 +17,12 @@ SYS_FUNC(reboot)`
`17`	`17`	`printxval(bootflags3, cmd, "LINUX_REBOOT_CMD_???");`
`18`	`18`	`if (cmd == LINUX_REBOOT_CMD_RESTART2) {`
`19`	`19`	`tprints(", ");`
`20`		`- printstr(tcp, tcp->u_arg[3]);`
	`20`	`+ /*`
	`21`	`+ * The size of kernel buffer is 256 bytes and`
	`22`	`+ * the last byte is always zero, at most 255 bytes`
	`23`	`+ * are copied from the user space.`
	`24`	`+ */`
	`25`	`+ printstr_ex(tcp, tcp->u_arg[3], 255, QUOTE_0_TERMINATED);`
`21`	`26`	`}`
`22`	`27`	`return RVAL_DECODED;`
`23`	`28`	`}`