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From: Duoming Zhou <duoming@zju.edu.cn>
To: linux-kernel@vger.kernel.org
Cc: arend.vanspriel@broadcom.com,
	kvalo@kernel.org,
	konrad.dybcio@linaro.org,
	hdegoede@redhat.com,
	minipli@grsecurity.net,
	linux-wireless@vger.kernel.org,
	brcm80211@lists.linux.dev,
	brcm80211-dev-list.pdl@broadcom.com,
	Duoming Zhou <duoming@zju.edu.cn>
Subject: [PATCH] wifi: brcmfmac: pcie: handle randbuf allocation failure
Date: Fri,  1 Mar 2024 21:51:34 +0800
Message-Id: <20240301135134.29577-1-duoming@zju.edu.cn>
Precedence: bulk

The kzalloc() in brcmf_pcie_download_fw_nvram() will return
null if the physical memory has run out. As a result, if we
use get_random_bytes() to generate random bytes in the randbuf,
the null pointer dereference bug will happen.

Return -ENOMEM from brcmf_pcie_download_fw_nvram() if kzalloc()
fails for randbuf.

Fixes: 91918ce88d9f ("wifi: brcmfmac: pcie: Provide a buffer of random bytes to the device")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
index d7fb88bb6ae..5ab9c902e49 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
@@ -1730,6 +1730,8 @@ static int brcmf_pcie_download_fw_nvram(struct brcmf_pciedev_info *devinfo,
 
 			address -= rand_len;
 			randbuf = kzalloc(rand_len, GFP_KERNEL);
+			if (!randbuf)
+				return -ENOMEM;
 			get_random_bytes(randbuf, rand_len);
 			memcpy_toio(devinfo->tcm + address, randbuf, rand_len);
 			kfree(randbuf);
-- 
2.17.1