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authorKamalesh Babulal <kamalesh@linux.vnet.ibm.com>2018-07-20 15:16:42 +0530
committerJiri Kosina <jkosina@suse.cz>2018-07-23 12:12:00 +0200
commit6e9df95b76cad18f7b217bdad7bb8a26d63b8c47 (patch)
tree19c58f8bccc180f5e0d8a825f6965a5d342a9760 /kernel/livepatch
parenta48c7709fe42712e86d2d68e1c9c4d2ce14c6a16 (diff)
downloadlinux-6e9df95b76cad18f7b217bdad7bb8a26d63b8c47.tar.bz2
livepatch: Validate module/old func name length
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: stable@vger.kernel.org Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'kernel/livepatch')
-rw-r--r--kernel/livepatch/core.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 3a4656fb7047..5b77a7314e01 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -678,6 +678,9 @@ static int klp_init_func(struct klp_object *obj, struct klp_func *func)
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;
@@ -751,6 +754,9 @@ static int klp_init_object(struct klp_patch *patch, struct klp_object *obj)
if (!obj->funcs)
return -EINVAL;
+ if (klp_is_module(obj) && strlen(obj->name) >= MODULE_NAME_LEN)
+ return -EINVAL;
+
obj->patched = false;
obj->mod = NULL;