diff options
| author | David Woodhouse <David.Woodhouse@intel.com> | 2013-03-14 13:23:11 +0000 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2013-03-18 11:40:21 +0000 |
| commit | 63662139e519ce06090b2759cf4a1d291b9cc0e2 (patch) | |
| tree | 65fe475f0f13719da4f78a85d44116a5c23ba7d1 | |
| parent | fe9ab00f8354a4c388e30301859c5741590c3809 (diff) | |
params: Fix potential memory leak in add_sysfs_param()
On allocation failure, it would fail to free the old attrs array which
was no longer referenced by anything (since it would free the old
module_param_attrs struct on the way out).
Comment the suspicious-looking krealloc() usage to explain why it *isn't*
actually buggy, despite looking like a classic realloc() usage bug.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
| -rw-r--r-- | kernel/params.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/params.c b/kernel/params.c index ed35345be536..53b958fcd639 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -613,10 +613,13 @@ static __modinit int add_sysfs_param(struct module_kobject *mk, sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1), GFP_KERNEL); if (!new) { - kfree(mk->mp); + kfree(attrs); err = -ENOMEM; goto fail; } + /* Despite looking like the typical realloc() bug, this is safe. + * We *want* the old 'attrs' to be freed either way, and we'll store + * the new one in the success case. */ attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL); if (!attrs) { err = -ENOMEM; |