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>
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 5bc5870..837469a 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1187,17 +1187,16 @@
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 = {
