From d0915b2255bfbdd537fd6a52f9a0a7037ecbe2d5 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 31 Oct 2014 13:40:39 +0300 Subject: [PATCH] staging: r8188eu: get a string from the user correctly The original code had two bugs: 1) It didn't check if the string was zero length so it could oops when it tried to dereference the ZERO_SIZE_PTR. 2) It didn't enforce that the string was NUL terminated. It was also messy as pants. Signed-off-by: Dan Carpenter Signed-off-by: Greg Kroah-Hartman --- .../staging/rtl8188eu/os_dep/rtw_android.c | 22 +++++-------------- 1 file changed, 6 insertions(+), 16 deletions(-) diff --git a/drivers/staging/rtl8188eu/os_dep/rtw_android.c b/drivers/staging/rtl8188eu/os_dep/rtw_android.c index d9d55d12fd5f..b40317822aed 100644 --- a/drivers/staging/rtl8188eu/os_dep/rtw_android.c +++ b/drivers/staging/rtl8188eu/os_dep/rtw_android.c @@ -162,22 +162,12 @@ int rtw_android_priv_cmd(struct net_device *net, struct ifreq *ifr, int cmd) ret = -EFAULT; goto exit; } - command = kmalloc(priv_cmd.total_len, GFP_KERNEL); - if (!command) { - DBG_88E("%s: failed to allocate memory\n", __func__); - ret = -ENOMEM; - goto exit; - } - if (!access_ok(VERIFY_READ, priv_cmd.buf, priv_cmd.total_len)) { - DBG_88E("%s: failed to access memory\n", __func__); - ret = -EFAULT; - goto exit; - } - if (copy_from_user(command, (char __user *)priv_cmd.buf, - priv_cmd.total_len)) { - ret = -EFAULT; - goto exit; - } + if (priv_cmd.total_len < 1) + return -EINVAL; + command = memdup_user(priv_cmd.buf, priv_cmd.total_len); + if (IS_ERR(command)) + return PTR_ERR(command); + command[priv_cmd.total_len - 1] = 0; DBG_88E("%s: Android private cmd \"%s\" on %s\n", __func__, command, ifr->ifr_name); cmd_num = rtw_android_cmdstr_to_num(command); -- 2.20.1