diff options
| author | Duoming Zhou <duoming@zju.edu.cn> | 2024-03-06 22:04:37 +0800 |
|---|---|---|
| committer | Kalle Valo <kvalo@kernel.org> | 2024-03-12 17:32:25 +0200 |
| commit | 316f790ebcf94bdf59f794b7cdea4068dc676d4c (patch) | |
| tree | 26e017c9ab6dc1ae5eff5af37270cc48b1a9f965 | |
| parent | 789c17185fb0f39560496c2beab9b57ce1d0cbe7 (diff) | |
wifi: brcmfmac: pcie: handle randbuf allocation failure
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.
In order to prevent allocation failure, this patch adds a separate
function using buffer on kernel stack to generate random bytes in
the randbuf, which could prevent the kernel stack from overflow.
Fixes: 91918ce88d9f ("wifi: brcmfmac: pcie: Provide a buffer of random bytes to the device")
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240306140437.18177-1-duoming@zju.edu.cn
| -rw-r--r-- | drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c index d7fb88bb6ae1..06698a714b52 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c @@ -1675,6 +1675,15 @@ struct brcmf_random_seed_footer { #define BRCMF_RANDOM_SEED_MAGIC 0xfeedc0de #define BRCMF_RANDOM_SEED_LENGTH 0x100 +static noinline_for_stack void +brcmf_pcie_provide_random_bytes(struct brcmf_pciedev_info *devinfo, u32 address) +{ + u8 randbuf[BRCMF_RANDOM_SEED_LENGTH]; + + get_random_bytes(randbuf, BRCMF_RANDOM_SEED_LENGTH); + memcpy_toio(devinfo->tcm + address, randbuf, BRCMF_RANDOM_SEED_LENGTH); +} + static int brcmf_pcie_download_fw_nvram(struct brcmf_pciedev_info *devinfo, const struct firmware *fw, void *nvram, u32 nvram_len) @@ -1717,7 +1726,6 @@ static int brcmf_pcie_download_fw_nvram(struct brcmf_pciedev_info *devinfo, .length = cpu_to_le32(rand_len), .magic = cpu_to_le32(BRCMF_RANDOM_SEED_MAGIC), }; - void *randbuf; /* Some Apple chips/firmwares expect a buffer of random * data to be present before NVRAM @@ -1729,10 +1737,7 @@ static int brcmf_pcie_download_fw_nvram(struct brcmf_pciedev_info *devinfo, sizeof(footer)); address -= rand_len; - randbuf = kzalloc(rand_len, GFP_KERNEL); - get_random_bytes(randbuf, rand_len); - memcpy_toio(devinfo->tcm + address, randbuf, rand_len); - kfree(randbuf); + brcmf_pcie_provide_random_bytes(devinfo, address); } } else { brcmf_dbg(PCIE, "No matching NVRAM file found %s\n", |