4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Kamalesh Babulal <kamal...@linux.vnet.ibm.com>
commit 6e9df95b76cad18f7b217bdad7bb8a26d63b8c47 upstream.
livepatch module author can pass module name/old function name with more
than the defined character limit. With obj->name length greater than
MODULE_NAME_LEN, the livepatch module gets loaded but waits forever on
the module specified by obj->name to be loaded. It also populates a /sys
directory with an untruncated object name.
In the case of funcs->old_name length greater then KSYM_NAME_LEN, it
would not match against any of the symbol table entries. Instead loop
through the symbol table comparing them against a nonexisting function,
which can be avoided.
The same issues apply, to misspelled/incorrect names. At least gatekeep
the modules with over the limit string length, by checking for their
length during livepatch module registration.
Cc: sta...@vger.kernel.org
Signed-off-by: Kamalesh Babulal <kamal...@linux.vnet.ibm.com>
Acked-by: Josh Poimboeuf <jpoim...@redhat.com>
Signed-off-by: Jiri Kosina <jkos...@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
kernel/livepatch/core.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -605,6 +605,9 @@ static int klp_init_func(struct klp_obje
if (!func->old_name || !func->new_func)
return -EINVAL;
+ if (strlen(func->old_name) >= KSYM_NAME_LEN)
+ return -EINVAL;
+
INIT_LIST_HEAD(&func->stack_node);
func->patched = false;
func->transition = false;
@@ -678,6 +681,9 @@ static int klp_init_object(struct klp_pa
if (!obj->funcs)
return -EINVAL;
+ if (klp_is_module(obj) && strlen(obj->name) >= MODULE_NAME_LEN)
+ return -EINVAL;
+
obj->patched = false;
obj->mod = NULL;
