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authorLi RongQing <lirongqing@baidu.com>2019-03-07 04:16:24 +0300
committerPaul Moore <paul@paul-moore.com>2019-03-19 02:11:49 +0300
commit95e0b46fcebd7dbf6850dee96046e4c4ddc7f69c (patch)
tree96f51a145ebd0a123a41fe995ee11a0ec526f6bf /kernel/auditsc.c
parent9e98c678c2d6ae3a17cb2de55d17f69dddaa231b (diff)
downloadlinux-95e0b46fcebd7dbf6850dee96046e4c4ddc7f69c.tar.xz
audit: fix a memleak caused by auditing load module
module.name will be allocated unconditionally when auditing load module, and audit_log_start() can fail with other reasons, or audit_log_exit maybe not called, caused module.name is not freed so free module.name in audit_free_context and __audit_syscall_exit unreferenced object 0xffff88af90837d20 (size 8): comm "modprobe", pid 1036, jiffies 4294704867 (age 3069.138s) hex dump (first 8 bytes): 69 78 67 62 65 00 ff ff ixgbe... backtrace: [<0000000008da28fe>] __audit_log_kern_module+0x33/0x80 [<00000000c1491e61>] load_module+0x64f/0x3850 [<000000007fc9ae3f>] __do_sys_init_module+0x218/0x250 [<0000000000d4a478>] do_syscall_64+0x117/0x400 [<000000004924ded8>] entry_SYSCALL_64_after_hwframe+0x49/0xbe [<000000007dc331dd>] 0xffffffffffffffff Fixes: ca86cad7380e3 ("audit: log module name on init_module") Signed-off-by: Zhang Yu <zhangyu31@baidu.com> Signed-off-by: Li RongQing <lirongqing@baidu.com> [PM: manual merge fixup in __audit_syscall_exit()] Signed-off-by: Paul Moore <paul@paul-moore.com>
Diffstat (limited to 'kernel/auditsc.c')
-rw-r--r--kernel/auditsc.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index d1eab1d4a930..fa7b8047aab8 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -840,6 +840,13 @@ static inline void audit_proctitle_free(struct audit_context *context)
context->proctitle.len = 0;
}
+static inline void audit_free_module(struct audit_context *context)
+{
+ if (context->type == AUDIT_KERN_MODULE) {
+ kfree(context->module.name);
+ context->module.name = NULL;
+ }
+}
static inline void audit_free_names(struct audit_context *context)
{
struct audit_names *n, *next;
@@ -923,6 +930,7 @@ int audit_alloc(struct task_struct *tsk)
static inline void audit_free_context(struct audit_context *context)
{
+ audit_free_module(context);
audit_free_names(context);
unroll_tree_refs(context, NULL, 0);
free_tree_refs(context);
@@ -1266,7 +1274,6 @@ static void show_special(struct audit_context *context, int *call_panic)
audit_log_format(ab, "name=");
if (context->module.name) {
audit_log_untrustedstring(ab, context->module.name);
- kfree(context->module.name);
} else
audit_log_format(ab, "(null)");
@@ -1697,6 +1704,7 @@ void __audit_syscall_exit(int success, long return_code)
context->in_syscall = 0;
context->prio = context->state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
+ audit_free_module(context);
audit_free_names(context);
unroll_tree_refs(context, NULL, 0);
audit_free_aux(context);