grub2/0317-net-Fix-OOB-write-in-grub_net_search_config_file.patch

80 lines
2.7 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: B Horn <b@horn.uk>
Date: Tue, 11 Feb 2025 16:38:44 -0600
Subject: [PATCH] net: Fix OOB write in grub_net_search_config_file()
The function included a call to grub_strcpy() which copied data from an
environment variable to a buffer allocated in grub_cmd_normal(). The
grub_cmd_normal() didn't consider the length of the environment variable.
So, the copy operation could exceed the allocation and lead to an OOB
write. Fix the issue by replacing grub_strcpy() with grub_strlcpy() and
pass the underlying buffers size to the grub_net_search_config_file().
Fixes: CVE-2025-0624
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
grub-core/net/net.c | 7 ++++---
grub-core/normal/main.c | 2 +-
include/grub/net.h | 2 +-
3 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/grub-core/net/net.c b/grub-core/net/net.c
index 22d5cc3ba..6c8dfcba2 100644
--- a/grub-core/net/net.c
+++ b/grub-core/net/net.c
@@ -2023,14 +2023,15 @@ grub_config_search_through (char *config, char *suffix,
}
grub_err_t
-grub_net_search_config_file (char *config)
+grub_net_search_config_file (char *config, grub_size_t config_buf_len)
{
- grub_size_t config_len;
+ grub_size_t config_len, suffix_len;
char *suffix;
config_len = grub_strlen (config);
config[config_len] = '-';
suffix = config + config_len + 1;
+ suffix_len = config_buf_len - (config_len + 1);
struct grub_net_network_level_interface *inf;
FOR_NET_NETWORK_LEVEL_INTERFACES (inf)
@@ -2056,7 +2057,7 @@ grub_net_search_config_file (char *config)
if (client_uuid)
{
- grub_strcpy (suffix, client_uuid);
+ grub_strlcpy (suffix, client_uuid, suffix_len);
if (grub_config_search_through (config, suffix, 1, 0) == 0)
return GRUB_ERR_NONE;
}
diff --git a/grub-core/normal/main.c b/grub-core/normal/main.c
index 86ffb388d..cad840e06 100644
--- a/grub-core/normal/main.c
+++ b/grub-core/normal/main.c
@@ -360,7 +360,7 @@ grub_try_normal_prefix (const char *prefix)
return err;
grub_snprintf (config, config_len, "%s/grub.cfg", prefix);
- err = grub_net_search_config_file (config);
+ err = grub_net_search_config_file (config, config_len);
}
if (err != GRUB_ERR_NONE)
diff --git a/include/grub/net.h b/include/grub/net.h
index 273afbddf..d280acd72 100644
--- a/include/grub/net.h
+++ b/include/grub/net.h
@@ -655,7 +655,7 @@ void
grub_net_remove_dns_server (const struct grub_net_network_level_address *s);
grub_err_t
-grub_net_search_config_file (char *config);
+grub_net_search_config_file (char *config, grub_size_t config_buf_len);
extern char *grub_net_default_server;