| Message ID | 20240830102314.409307-1-Yibin.Ding@unisoc.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere, archived |
| Headers | show |
| Series | [1/2] interconnect: Add character pointer initialization | expand |
On Fri, Aug 30, 2024 at 06:23:14PM +0800, Yibin Ding wrote: > From: Yibin Ding <Yibin.ding@unisoc.com> > > For uninitialized nodes such as > /sys/kernel/debug/interconnect/test_client/dst_node, if the cat operation > is performed directly without writing content to the node, it will cause > a crash due to accessing a null pointer. So it is necessary to add a null > pointer check in the debugfs_read_file_str() function. > > Signed-off-by: Yibin Ding <Yibin.ding@unisoc.com> > --- > fs/debugfs/file.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c > index c6f4a9a98b85..8bbe7df6dfd1 100644 > --- a/fs/debugfs/file.c > +++ b/fs/debugfs/file.c > @@ -970,6 +970,10 @@ ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf, > return ret; > > str = *(char **)file->private_data; > + if (!str) { > + debugfs_file_put(dentry); > + return -EINVAL; > + } How can private_data be NULL now with patch 1 in this series? I guess the allocation could fail, but really, how can it? thanks, greg k-h
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index c6f4a9a98b85..8bbe7df6dfd1 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -970,6 +970,10 @@ ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf, return ret; str = *(char **)file->private_data; + if (!str) { + debugfs_file_put(dentry); + return -EINVAL; + } len = strlen(str) + 1; copy = kmalloc(len, GFP_KERNEL); if (!copy) {