From: Dan Carpenter <dan.carpenter@oracle.com> stable inclusion from stable-v5.10.137 commit 05ceda14ef7c73104e709c414c3680d8a59f51d4 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 7a4836560a6198d245d5732e26f94898b12eb760 ] The simple_write_to_buffer() function will succeed if even a single byte is initialized. However, we need to initialize the whole buffer to prevent information leaks. Just use memdup_user(). Fixes: ff974e408334 ("wil6210: debugfs interface to send raw WMI command") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com> Link: https://lore.kernel.org/r/Ysg14NdKAZF/hcNG@kili Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> --- drivers/net/wireless/ath/wil6210/debugfs.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/drivers/net/wireless/ath/wil6210/debugfs.c b/drivers/net/wireless/ath/wil6210/debugfs.c index 2d618f90afa7..58c98e58bccb 100644 --- a/drivers/net/wireless/ath/wil6210/debugfs.c +++ b/drivers/net/wireless/ath/wil6210/debugfs.c @@ -1012,18 +1012,12 @@ static ssize_t wil_write_file_wmi(struct file *file, const char __user *buf, u16 cmdid; int rc, rc1; - if (cmdlen < 0) + if (cmdlen < 0 || *ppos != 0) return -EINVAL; - wmi = kmalloc(len, GFP_KERNEL); - if (!wmi) - return -ENOMEM; - - rc = simple_write_to_buffer(wmi, len, ppos, buf, len); - if (rc < 0) { - kfree(wmi); - return rc; - } + wmi = memdup_user(buf, len); + if (IS_ERR(wmi)) + return PTR_ERR(wmi); cmd = (cmdlen > 0) ? &wmi[1] : NULL; cmdid = le16_to_cpu(wmi->command_id); -- 2.20.1