Commit cba8aafe authored Sep 22, 2009 by Vincent Li Committed by Linus Torvalds Sep 23, 2009

fs/proc/base.c: fix proc_fault_inject_write() input sanity check



Remove obfuscated zero-length input check and return -EINVAL instead of
-EIO error to make the error message clear to user.  Add whitespace
stripping.  No functionality changes.

The old code:

echo  1  > /proc/pid/make-it-fail (ok)
echo 1foo > /proc/pid/make-it-fail (-bash: echo: write error: Input/output error)

The new code:

echo  1  > /proc/pid/make-it-fail (ok)
echo 1foo > /proc/pid/make-it-fail (-bash: echo: write error: Invalid argument)

This patch is conservative in changes to not breaking existing
scripts/applications.

Signed-off-by: Vincent Li <macli@brc.ubc.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent fb92a4b0

fs/proc/base.c

+5 −6

Original line number	Diff line number	Diff line
		@@ -1187,17 +1187,16 @@ static ssize_t proc_fault_inject_write(struct file * file,
		count = sizeof(buffer) - 1;
		if (copy_from_user(buffer, buf, count))
		return -EFAULT;
		make_it_fail = simple_strtol(buffer, &end, 0);
		if (*end == '\n')
		end++;
		make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
		if (*end)
		return -EINVAL;
		task = get_proc_task(file->f_dentry->d_inode);
		if (!task)
		return -ESRCH;
		task->make_it_fail = make_it_fail;
		put_task_struct(task);
		if (end - buffer == 0)
		return -EIO;
		return end - buffer;

		return count;
		}

		static const struct file_operations proc_fault_inject_operations = {

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