netdev - [PATCH V3 bpf] xdp: add NULL pointer check in __xdp

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20180726141703.6236-1-ap420073@gmail.com>
Date:   Thu, 26 Jul 2018 23:17:03 +0900
From:   Taehee Yoo <ap420073@...il.com>
To:     daniel@...earbox.net, ast@...nel.org
Cc:     netdev@...r.kernel.org, bjorn.topel@...el.com, brouer@...hat.com,
        kafai@...com, jakub.kicinski@...ronome.com,
        Taehee Yoo <ap420073@...il.com>
Subject: [PATCH V3 bpf] xdp: add NULL pointer check in __xdp_return()

rhashtable_lookup() can return NULL. so that NULL pointer
check routine should be added.

Fixes: 02b55e5657c3 ("xdp: add MEM_TYPE_ZERO_COPY")
Acked-by: Martin KaFai Lau <kafai@...com>
Signed-off-by: Taehee Yoo <ap420073@...il.com>
---
V3 : reduce code line
V2 : add WARN_ON_ONCE when xa is NULL.
 net/core/xdp.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/core/xdp.c b/net/core/xdp.c
index 9d1f220..6771f18 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -345,7 +345,8 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
 		rcu_read_lock();
 		/* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */
 		xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
-		xa->zc_alloc->free(xa->zc_alloc, handle);
+		if (!WARN_ON_ONCE(!xa))
+			xa->zc_alloc->free(xa->zc_alloc, handle);
 		rcu_read_unlock();
 	default:
 		/* Not possible, checked in xdp_rxq_info_reg_mem_model() */
-- 
2.9.3