If there is a failure during copy_from_user or user-provided data buffer is invalid, rtl_debugfs_set_write_reg should return negative error code instead of a positive value count. Fix this bug by returning correct error code. Moreover, the check of buffer against null is removed since it will be handled by copy_from_user. Fixes: 610247f46feb ("rtlwifi: Improve debugging by using debugfs") Signed-off-by: Wei Chen <harperchen1110@xxxxxxxxx> --- Changes in v2: - Add fixes commit tag - Correct the subject prefix drivers/net/wireless/realtek/rtlwifi/debug.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/realtek/rtlwifi/debug.c b/drivers/net/wireless/realtek/rtlwifi/debug.c index 0b1bc04cb6ad..3e7f9b4f1f19 100644 --- a/drivers/net/wireless/realtek/rtlwifi/debug.c +++ b/drivers/net/wireless/realtek/rtlwifi/debug.c @@ -278,8 +278,8 @@ static ssize_t rtl_debugfs_set_write_reg(struct file *filp, tmp_len = (count > sizeof(tmp) - 1 ? sizeof(tmp) - 1 : count); - if (!buffer || copy_from_user(tmp, buffer, tmp_len)) - return count; + if (copy_from_user(tmp, buffer, tmp_len)) + return -EFAULT; tmp[tmp_len] = '\0'; @@ -287,7 +287,7 @@ static ssize_t rtl_debugfs_set_write_reg(struct file *filp, num = sscanf(tmp, "%x %x %x", &addr, &val, &len); if (num != 3) - return count; + return -EINVAL; switch (len) { case 1: -- 2.25.1