| From eb09405438b2e28123b6392fb97dc1152c4e8235 Mon Sep 17 00:00:00 2001 |
| From: Li RongQing <lirongqing@baidu.com> |
| Date: Thu, 7 Mar 2019 09:16:24 +0800 |
| Subject: audit: fix a memleak caused by auditing load module |
| |
| [ Upstream commit 95e0b46fcebd7dbf6850dee96046e4c4ddc7f69c ] |
| |
| 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> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| kernel/auditsc.c | 10 +++++++++- |
| 1 file changed, 9 insertions(+), 1 deletion(-) |
| |
| diff --git a/kernel/auditsc.c b/kernel/auditsc.c |
| index d1eab1d4a930e..fa7b8047aab89 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); |
| -- |
| 2.20.1 |
| |