diff options
| author | Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> | 2008-02-14 10:26:24 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-02-25 16:34:17 +0100 |
| commit | ae0027869db7d28563cd783865fab04ffd18419c (patch) | |
| tree | 9d57da1dd823e9413fd539a4a60e09df6fe630f8 /fs | |
| parent | 2d07b255c7b8a9723010e5c74778e058dc05162e (diff) | |
latencytop: fix kernel panic while reading latency proc file
Reading /proc/<pid>/latency or /proc/<pid>/task/<tid>/latency could cause
NULL pointer dereference.
In lstats_open(), get_proc_task() can return NULL, in which case the kernel
will oops at lstats_show_proc() because m->private is NULL.
When get_proc_task() returns NULL, the kernel should return -ENOENT.
This can be reproduced by the following script.
while :
do
date
bash -c 'ls > ls.$$' &
pid=$!
cat /proc/$pid/latency &
cat /proc/$pid/latency &
cat /proc/$pid/latency &
cat /proc/$pid/latency
done
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/proc/base.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 96ee899d6502..989e3078d7af 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -350,6 +350,8 @@ static int lstats_open(struct inode *inode, struct file *file) struct seq_file *m; struct task_struct *task = get_proc_task(inode); + if (!task) + return -ENOENT; ret = single_open(file, lstats_show_proc, NULL); if (!ret) { m = file->private_data; |