Commit 5d863b89 authored by KOSAKI Motohiro's avatar KOSAKI Motohiro Committed by Linus Torvalds

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: default avatarKOSAKI 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: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8c5cd6f3
...@@ -1021,21 +1021,24 @@ static ssize_t oom_adjust_write(struct file *file, const char __user *buf, ...@@ -1021,21 +1021,24 @@ static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos) size_t count, loff_t *ppos)
{ {
struct task_struct *task; struct task_struct *task;
char buffer[PROC_NUMBUF], *end; char buffer[PROC_NUMBUF];
int oom_adjust; long oom_adjust;
unsigned long flags; unsigned long flags;
int err;
memset(buffer, 0, sizeof(buffer)); memset(buffer, 0, sizeof(buffer));
if (count > sizeof(buffer) - 1) if (count > sizeof(buffer) - 1)
count = sizeof(buffer) - 1; count = sizeof(buffer) - 1;
if (copy_from_user(buffer, buf, count)) if (copy_from_user(buffer, buf, count))
return -EFAULT; return -EFAULT;
oom_adjust = simple_strtol(buffer, &end, 0);
err = strict_strtol(strstrip(buffer), 0, &oom_adjust);
if (err)
return -EINVAL;
if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
oom_adjust != OOM_DISABLE) oom_adjust != OOM_DISABLE)
return -EINVAL; return -EINVAL;
if (*end == '\n')
end++;
task = get_proc_task(file->f_path.dentry->d_inode); task = get_proc_task(file->f_path.dentry->d_inode);
if (!task) if (!task)
return -ESRCH; return -ESRCH;
...@@ -1054,9 +1057,8 @@ static ssize_t oom_adjust_write(struct file *file, const char __user *buf, ...@@ -1054,9 +1057,8 @@ static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
unlock_task_sighand(task, &flags); unlock_task_sighand(task, &flags);
put_task_struct(task); put_task_struct(task);
if (end - buffer == 0)
return -EIO; return count;
return end - buffer;
} }
static const struct file_operations proc_oom_adjust_operations = { static const struct file_operations proc_oom_adjust_operations = {
......
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