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SubjectRe: [PATCH] net: tipc: Fix a possible null-pointer dereference in tipc_publ_purge()
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On 7/25/19 5:20 PM, Jia-Ju Bai wrote:
> In tipc_publ_purge(), there is an if statement on 215 to
> check whether p is NULL:
> if (p)
>
> When p is NULL, it is used on line 226:
> kfree_rcu(p, rcu);
>
> Thus, a possible null-pointer dereference may occur.
>
> To fix this bug, p is checked before being used.
>
> This bug is found by a static analysis tool STCheck written by us.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
> ---
> net/tipc/name_distr.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/net/tipc/name_distr.c b/net/tipc/name_distr.c
> index 44abc8e9c990..241ed2274473 100644
> --- a/net/tipc/name_distr.c
> +++ b/net/tipc/name_distr.c
> @@ -223,7 +223,8 @@ static void tipc_publ_purge(struct net *net, struct publication *publ, u32 addr)
> publ->key);
> }
>
> - kfree_rcu(p, rcu);
> + if (p)

No, I don't think so because kfree_rcu() will internally check if "p"
pointer is NULL or not.

> + kfree_rcu(p, rcu);
> }
>
> /**
>

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