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| author | Li RongQing <lirongqing@baidu.com> | 2019-03-07 02:16:24 +0100 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2019-03-19 00:11:49 +0100 |
| commit | 95e0b46fcebd7dbf6850dee96046e4c4ddc7f69c (patch) | |
| tree | 96f51a145ebd0a123a41fe995ee11a0ec526f6bf /kernel/auditsc.c | |
| parent | Linux 5.1-rc1 (diff) | |
| download | linux-95e0b46fcebd7dbf6850dee96046e4c4ddc7f69c.tar.xz linux-95e0b46fcebd7dbf6850dee96046e4c4ddc7f69c.zip | |
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.c | 10 |
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); |