From: Alan Cox <alan@linux.intel.com>
Date: Mon, 29 Aug 2016 16:46:10 +0000 (+0100)
Subject: devsys: check for over end copies for ps
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=64f497a015558fded362b18e965371ec69385fde;p=FUZIX.git

devsys: check for over end copies for ps

Doesn't matter too much today but it will when we have MMU support
---

diff --git a/Kernel/devsys.c b/Kernel/devsys.c
index 8850450d..a76df30f 100644
--- a/Kernel/devsys.c
+++ b/Kernel/devsys.c
@@ -39,7 +39,9 @@ int sys_read(uint8_t minor, uint8_t rawflag, uint8_t flag)
 			uzero(udata.u_base, udata.u_count);
 		return udata.u_count;
 	case 3:
-		if (udata.u_offset >= PTABSIZE * sizeof(struct p_tab))
+		if (udata.u_count > sizeof(struct p_tab))
+			udata.u_count = sizeof(struct p_tab);
+		if (udata.u_offset + udata.u_count > PTABSIZE * sizeof(struct p_tab))
 			return 0;
 		return uputsys(addr + udata.u_offset, udata.u_count);
 #ifdef CONFIG_NET_NATIVE