From 4bce110b08396e01b9068cd967f7f01ce1c5689f Mon Sep 17 00:00:00 2001 From: Sergey Matyukevich Date: Wed, 13 Nov 2019 11:06:47 +0000 Subject: [PATCH] qtnfmac: fix using skb after free BugLink: https://bugs.launchpad.net/bugs/1860490 [ Upstream commit 4a33f21cef84b1b933958c99ed5dac1726214b35 ] KASAN reported use-after-free error: [ 995.220767] BUG: KASAN: use-after-free in qtnf_cmd_send_with_reply+0x169/0x3e0 [qtnfmac] [ 995.221098] Read of size 2 at addr ffff888213d1ded0 by task kworker/1:1/71 The issue in qtnf_cmd_send_with_reply impacts all the commands that do not need response other then return code. For such commands, consume_skb is used for response skb and right after that return code in response skb is accessed. Signed-off-by: Sergey Matyukevich Signed-off-by: Kalle Valo Signed-off-by: Sasha Levin Signed-off-by: Kamal Mostafa Signed-off-by: Khalid Elmously --- drivers/net/wireless/quantenna/qtnfmac/commands.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/quantenna/qtnfmac/commands.c b/drivers/net/wireless/quantenna/qtnfmac/commands.c index dc0c7244b60e..c0c32805fb8d 100644 --- a/drivers/net/wireless/quantenna/qtnfmac/commands.c +++ b/drivers/net/wireless/quantenna/qtnfmac/commands.c @@ -83,6 +83,7 @@ static int qtnf_cmd_send_with_reply(struct qtnf_bus *bus, struct qlink_cmd *cmd; struct qlink_resp *resp = NULL; struct sk_buff *resp_skb = NULL; + int resp_res = 0; u16 cmd_id; u8 mac_id; u8 vif_id; @@ -113,6 +114,7 @@ static int qtnf_cmd_send_with_reply(struct qtnf_bus *bus, } resp = (struct qlink_resp *)resp_skb->data; + resp_res = le16_to_cpu(resp->result); ret = qtnf_cmd_check_reply_header(resp, cmd_id, mac_id, vif_id, const_resp_size); if (ret) @@ -128,8 +130,8 @@ out: else consume_skb(resp_skb); - if (!ret && resp) - return qtnf_cmd_resp_result_decode(le16_to_cpu(resp->result)); + if (!ret) + return qtnf_cmd_resp_result_decode(resp_res); pr_warn("VIF%u.%u: cmd 0x%.4X failed: %d\n", mac_id, vif_id, cmd_id, ret); -- 2.39.5