@@ -123,7 +123,7 @@ static ssize_t target_core_item_dbroot_store(struct config_item *item,
goto unlock;
}
- read_bytes = snprintf(db_root_stage, DB_ROOT_LEN, "%s", page);
+ read_bytes = scnprintf(db_root_stage, DB_ROOT_LEN, "%s", page);
if (!read_bytes)
goto unlock;
@@ -143,7 +143,7 @@ static ssize_t target_core_item_dbroot_store(struct config_item *item,
}
filp_close(fp, NULL);
- strncpy(db_root, db_root_stage, read_bytes);
+ strscpy(db_root, db_root_stage);
pr_debug("Target_Core_ConfigFS: db_root set to %s\n", db_root);
r = read_bytes;
@@ -3664,7 +3664,7 @@ static void target_init_dbroot(void)
}
filp_close(fp, NULL);
- strncpy(db_root, db_root_stage, DB_ROOT_LEN);
+ strscpy(db_root, db_root_stage);
pr_debug("Target_Core_ConfigFS: db_root set to %s\n", db_root);
}
strncpy() is deprecated for NUL-terminated destination buffers; use strscpy() instead. The destination buffer db_root is only used with "%s" format strings and must therefore be NUL-terminated, but not NUL-padded. Use scnprintf() because snprintf() could return a value >= DB_ROOT_LEN and lead to an out-of-bounds access. This doesn't happen because count is explicitly checked against DB_ROOT_LEN before. However, scnprintf() always returns the number of characters actually written to the string buffer, which is always within the bounds of db_root_stage, and should be preferred over snprintf(). The size parameter of strscpy() is optional and since DB_ROOT_LEN is the size of the destination buffer, it can be removed. Remove it to simplify the code. Compile-tested only. Link: https://github.com/KSPP/linux/issues/90 Link: https://github.com/KSPP/linux/issues/105 Cc: linux-hardening@vger.kernel.org Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> --- Changes in v2: - Improve the commit message and replace another strncpy() as suggested by Kees Cook - Replace snprintf() with scnprintf() - Link to v1: https://lore.kernel.org/r/20250226121003.359876-1-thorsten.blum@linux.dev/ --- drivers/target/target_core_configfs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)