From 085cbdafca9c3d7bc2f27523a343f61db82f2ccb Mon Sep 17 00:00:00 2001
From: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Date: Mon, 15 Nov 2021 19:26:51 +0100
Subject: [PATCH] pxe: simplify label_boot()
Coverity CID 131256 indicates a possible buffer overflow in label_boot().
This would only occur if the size of the downloaded file would exceed 4
GiB. But anyway we can simplify the code by using snprintf() and checking
the return value.
Addresses-Coverity-ID: 131256 ("Security best practices violations (STRING_OVERFLOW)")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
Reviewed-by: Artem Lapkin <email2tema@gmail.com>
---
boot/pxe_utils.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/boot/pxe_utils.c b/boot/pxe_utils.c
index b08aee9896..defbe465e4 100644
--- a/boot/pxe_utils.c
+++ b/boot/pxe_utils.c
@@ -532,11 +532,10 @@ static int label_boot(struct pxe_context *ctx, struct pxe_label *label)
}
initrd_addr_str = env_get("ramdisk_addr_r");
- strcpy(initrd_filesize, simple_xtoa(size));
-
- strncpy(initrd_str, initrd_addr_str, 18);
- strcat(initrd_str, ":");
- strncat(initrd_str, initrd_filesize, 9);
+ size = snprintf(initrd_str, sizeof(initrd_str), "%s:%lx",
+ initrd_addr_str, size);
+ if (size >= sizeof(initrd_str))
+ return 1;
}
if (get_relfile_envaddr(ctx, label->kernel, "kernel_addr_r",
--
2.39.5