From: Wei Chen <harperchen1110@xxxxxxxxx> [ Upstream commit 905a9241e4e8c15d2c084fee916280514848fe35 ] If there is a failure during copy_from_user or user-provided data buffer is invalid, rtl_debugfs_set_write_rfreg 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> Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230326053138.91338-1-harperchen1110@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 0b1bc04cb6adb..602717928887d 100644 --- a/drivers/net/wireless/realtek/rtlwifi/debug.c +++ b/drivers/net/wireless/realtek/rtlwifi/debug.c @@ -375,8 +375,8 @@ static ssize_t rtl_debugfs_set_write_rfreg(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'; @@ -386,7 +386,7 @@ static ssize_t rtl_debugfs_set_write_rfreg(struct file *filp, if (num != 4) { rtl_dbg(rtlpriv, COMP_ERR, DBG_DMESG, "Format is <path> <addr> <mask> <data>\n"); - return count; + return -EINVAL; } rtl_set_rfreg(hw, path, addr, bitmask, data); -- 2.39.2