From: David Engraf <david.engraf@sysgo.com>
Date: Fri, 8 Aug 2014 21:23:16 +0000 (-0700)
Subject: initramfs: add write error checks
X-Git-Tag: v3.17-rc1~73^2~84
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=9687fd9101afaa1c4b1de7ffd2f9d7e53f45b29f;p=karo-tx-linux.git

initramfs: add write error checks

On a system with low memory extracting the initramfs may fail.  If this
happens the user gets "Failed to execute /init" instead of an initramfs
error.

Check return value of sys_write and call error() when the write was
incomplete or failed.

Signed-off-by: David Engraf <david.engraf@sysgo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/init/initramfs.c b/init/initramfs.c
index a7566031242e..bece48c3461e 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -369,7 +369,8 @@ static int __init do_name(void)
 static int __init do_copy(void)
 {
 	if (count >= body_len) {
-		xwrite(wfd, victim, body_len);
+		if (xwrite(wfd, victim, body_len) != body_len)
+			error("write error");
 		sys_close(wfd);
 		do_utime(vcollected, mtime);
 		kfree(vcollected);
@@ -377,7 +378,8 @@ static int __init do_copy(void)
 		state = SkipIt;
 		return 0;
 	} else {
-		xwrite(wfd, victim, count);
+		if (xwrite(wfd, victim, count) != count)
+			error("write error");
 		body_len -= count;
 		eat(count);
 		return 1;