Re: audit-related slab memory leak in recent -mm kernels?
On Fri, Feb 24, 2006 at 01:41:24PM -0500, Valdis.Kletnieks(a)vt.edu wrote:
For a while, I've been seeing a pretty serious leak in slab-32
entries in -mm
kernels. Doing a quilt bisection on -mm calls out git-audit.patch as the
offender.
In kernel/auditsc.c, we have audit_inode_context(), which does:
ctx = kmalloc(len, GFP_KERNEL);
...
context->names[idx].ctx = ctx;
but the only obvious kfree() I can find is in audit_free_names(), but that
one is (a) inside an if statement along with a printk(KERN_ERR) and (b) has
a '#if AUDIT_DEBUG == 2' around it.
[/usr/src/linux-2.6.16-rc4-mm2/kernel]1 grep -n '\.ctx' *.c
auditsc.c:384: kfree(context->names[i].ctx);
auditsc.c:686: if (context->names[i].ctx) {
auditsc.c:688: context->names[i].ctx);
auditsc.c:961: context->names[idx].ctx = ctx;
Is this my memory leak? If so, who is supposed to be freeing it?
That kfree is misplaced. It should be here. Does this solve it on
your end?
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 4626c35..1867fc3 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -381,7 +381,6 @@ static inline void audit_free_names(stru
printk(KERN_ERR "names[%d] = %p = %s\n", i,
context->names[i].name,
context->names[i].name ?: "(null)");
- kfree(context->names[i].ctx);
}
dump_stack();
return;
@@ -392,9 +391,11 @@ static inline void audit_free_names(stru
context->ino_count = 0;
#endif
- for (i = 0; i < context->name_count; i++)
+ for (i = 0; i < context->name_count; i++) {
if (context->names[i].name)
__putname(context->names[i].name);
+ kfree(context->names[i].ctx);
+ }
context->name_count = 0;
if (context->pwd)
dput(context->pwd);