From: Jian Yu Date: Mon, 21 Nov 2016 05:46:48 +0000 (-0500) Subject: staging/lustre: Use proper number of bytes in copy_from_user X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=8d130c3b0fb6d7eddbe985ff941845f70b043957;p=openwrt%2Fstaging%2Fblogic.git staging/lustre: Use proper number of bytes in copy_from_user This patch removes the usage of MAX_STRING_SIZE from copy_from_user() and just copies enough bytes to cover count passed in. Signed-off-by: Jian Yu Reviewed-on: http://review.whamcloud.com/23462 Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-8774 Reviewed-by: John L. Hammond Signed-off-by: Oleg Drokin Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c index 8a2f02f33371..db4999246fea 100644 --- a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c +++ b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c @@ -400,10 +400,17 @@ int lprocfs_wr_uint(struct file *file, const char __user *buffer, char dummy[MAX_STRING_SIZE + 1], *end; unsigned long tmp; - dummy[MAX_STRING_SIZE] = '\0'; - if (copy_from_user(dummy, buffer, MAX_STRING_SIZE)) + if (count >= sizeof(dummy)) + return -EINVAL; + + if (count == 0) + return 0; + + if (copy_from_user(dummy, buffer, count)) return -EFAULT; + dummy[count] = '\0'; + tmp = simple_strtoul(dummy, &end, 0); if (dummy == end) return -EINVAL;