[PATCH 4/4] oom: fix oom_adjust_write() input sanity check.

[KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>]

Subject: [PATCH] oom: fix oom_adjust_write() input sanity check.

Andrew Morton pointed out oom_adjust_write() has very strange EIO
and new line handling. this patch fixes it.


Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>,
Cc: Andrew Morton <akpm@linux-foundation.org>,
---
 fs/proc/base.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

Index: b/fs/proc/base.c
===================================================================
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1033,12 +1033,15 @@ static ssize_t oom_adjust_write(struct f
 		count = sizeof(buffer) - 1;
 	if (copy_from_user(buffer, buf, count))
 		return -EFAULT;
+
+	strstrip(buffer);
 	oom_adjust = simple_strtol(buffer, &end, 0);
+	if (*end)
+		return -EINVAL;
 	if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
 	     oom_adjust != OOM_DISABLE)
 		return -EINVAL;
-	if (*end == '\n')
-		end++;
+
 	task = get_proc_task(file->f_path.dentry->d_inode);
 	if (!task)
 		return -ESRCH;
@@ -1057,9 +1060,8 @@ static ssize_t oom_adjust_write(struct f
 	task->signal->oom_adj = oom_adjust;
 	unlock_task_sighand(task, &flags);
 	put_task_struct(task);
-	if (end - buffer == 0)
-		return -EIO;
-	return end - buffer;
+
+	return count;
 }
 
 static const struct file_operations proc_oom_adjust_operations = {


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