tracing/uprobes: Fix to return -EFAULT if copy_from_user failed

mhiramat · rostedt · commit f3f58935edbc · 2018-10-10T22:19:11.000-04:00
Fix probe_mem_read() to return -EFAULT if copy_from_user() failed. The copy_from_user() returns remaining bytes when it failed, but probe_mem_read() caller expects it returns error code like as probe_kernel_read(). Link: http://lkml.kernel.org/r/153547306719.26502.8353484532699160223.stgit@devbox Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
@@ -105,7 +105,7 @@ probe_mem_read(void *dest, void *src, size_t size)
 {
 	void __user *vaddr = (void __force __user *)src;
 
-	return copy_from_user(dest, vaddr, size);
+	return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
 }
 /*
  * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max

Original file line number	Diff line number	Diff line change
`@@ -105,7 +105,7 @@ probe_mem_read(void dest, void src, size_t size)`
`105`	`105`	`{`
`106`	`106`	`void __user vaddr = (void __force __user )src;`
`107`	`107`
`108`		`- return copy_from_user(dest, vaddr, size);`
	`108`	`+ return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;`
`109`	`109`	`}`
`110`	`110`	`/*`
`111`	`111`	`* Fetch a null-terminated string. Caller MUST set (u32 )dest with max`