2022-08-23 01:51:59

by Gaosheng Cui

Subject: [PATCH] apparmor: fix a memleak in multi_transaction_new()

In multi_transaction_new(), the variable t is not freed or passed out
on the failure of copy_from_user(t->data, buf, size), which could lead
to a memleak.

Fix this bug by adding a put_multi_transaction(t) in the error path.

Fixes: 1dea3b41e84c5 ("apparmor: speed up transactional queries")
Signed-off-by: Gaosheng Cui <[email protected]>
---
security/apparmor/apparmorfs.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index d066ccc219e2..7160e7aa58b9 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -868,8 +868,10 @@ static struct multi_transaction *multi_transaction_new(struct file *file,
if (!t)
return ERR_PTR(-ENOMEM);
kref_init(&t->count);
- if (copy_from_user(t->data, buf, size))
+ if (copy_from_user(t->data, buf, size)) {
+ put_multi_transaction(t);
return ERR_PTR(-EFAULT);
+ }

return t;
}
--
2.25.1

2022-08-24 17:56:31

by John Johansen

Subject: Re: [PATCH] apparmor: fix a memleak in multi_transaction_new()

On 8/22/22 18:15, Gaosheng Cui wrote:
> In multi_transaction_new(), the variable t is not freed or passed out
> on the failure of copy_from_user(t->data, buf, size), which could lead
> to a memleak.
>
> Fix this bug by adding a put_multi_transaction(t) in the error path.
>
> Fixes: 1dea3b41e84c5 ("apparmor: speed up transactional queries")
> Signed-off-by: Gaosheng Cui <[email protected]>

yep, thanks. I will pull this into apparmor-next

Acked-by: John Johansen <[email protected]>

> ---
> security/apparmor/apparmorfs.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
> index d066ccc219e2..7160e7aa58b9 100644
> --- a/security/apparmor/apparmorfs.c
> +++ b/security/apparmor/apparmorfs.c
> @@ -868,8 +868,10 @@ static struct multi_transaction *multi_transaction_new(struct file *file,
> if (!t)
> return ERR_PTR(-ENOMEM);
> kref_init(&t->count);
> - if (copy_from_user(t->data, buf, size))
> + if (copy_from_user(t->data, buf, size)) {
> + put_multi_transaction(t);
> return ERR_PTR(-EFAULT);
> + }
>
> return t;
> }