uprobes/tracing: Ensure inode != NULL in create_trace_uprobe()
probe_event_enable/disable() check tu->inode != NULL at the start.
This is ugly, if igrab() can fail create_trace_uprobe() should not
succeed and "postpone" the failure.
And S_ISREG(inode->i_mode) check added by d24d7dbf is not safe.
Note: alloc_uprobe() should probably check igrab() != NULL as well.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 15b8ece..f7838cf 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -256,7 +256,7 @@
inode = igrab(path.dentry->d_inode);
path_put(&path);
- if (!S_ISREG(inode->i_mode)) {
+ if (!inode || !S_ISREG(inode->i_mode)) {
ret = -EINVAL;
goto fail_address_parse;
}
@@ -544,7 +544,7 @@
struct uprobe_trace_consumer *utc;
int ret = 0;
- if (!tu->inode || tu->consumer)
+ if (tu->consumer)
return -EINTR;
utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL);
@@ -568,7 +568,7 @@
static void probe_event_disable(struct trace_uprobe *tu, int flag)
{
- if (!tu->inode || !tu->consumer)
+ if (!tu->consumer)
return;
uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons);