This is a note to let you know that I've just added the patch titled wifi: rtlwifi: fix incorrect error codes in rtl_debugfs_set_write_reg() to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: wifi-rtlwifi-fix-incorrect-error-codes-in-rtl_debugf.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit ad2f3d20ee05ce644d868aea74cb9c03bdf99fa1 Author: Wei Chen <harperchen1110@xxxxxxxxx> Date: Sun Mar 26 05:42:17 2023 +0000 wifi: rtlwifi: fix incorrect error codes in rtl_debugfs_set_write_reg() [ Upstream commit 5dbe1f8eb8c5ac69394400a5b86fd81775e96c43 ] 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> Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230326054217.93492-1-harperchen1110@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/wireless/realtek/rtlwifi/debug.c b/drivers/net/wireless/realtek/rtlwifi/debug.c index deacc7a28d3a7..6a0dfc6d4905e 100644 --- a/drivers/net/wireless/realtek/rtlwifi/debug.c +++ b/drivers/net/wireless/realtek/rtlwifi/debug.c @@ -319,8 +319,8 @@ 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'; @@ -328,7 +328,7 @@ 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: