Allocate a NULL-terminated file path with special characters escaped,
safe for logging.
Signed-off-by: Kees Cook <keesc...@chromium.org>
---
include/linux/string_helpers.h | 3 +++
lib/string_helpers.c | 30 ++++++++++++++++++++++++++++++
2 files changed, 33 insertions(+)
diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h
index ee1e8f701eb1..63f06745c36d 100644
--- a/include/linux/string_helpers.h
+++ b/include/linux/string_helpers.h
@@ -3,6 +3,8 @@
#include <linux/types.h>
+struct file;
+
/* Descriptions of the types of units to
* print in */
enum string_size_units {
@@ -70,5 +72,6 @@ static inline int string_escape_str_any_np(const char *src,
char *dst,
char *kstrdup_quotable(char *src);
char *kstrdup_quotable_cmdline(struct task_struct *task);
+char *kstrdup_quotable_file(struct file *file);
#endif
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 142bed739fed..981e6655a9d4 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -10,6 +10,8 @@
#include <linux/export.h>
#include <linux/ctype.h>
#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/limits.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/string.h>
@@ -597,3 +599,31 @@ char *kstrdup_quotable_cmdline(struct task_struct *task)
return quoted;
}
EXPORT_SYMBOL_GPL(kstrdup_quotable_cmdline);
+
+/*
+ * Returns allocated NULL-terminated string containing pathname,
+ * with special characters escaped, able to be safely logged. If
+ * there is an error, the leading character will be "<".
+ */
+char *kstrdup_quotable_file(struct file *file)
+{
+ char *temp, *pathname;
+
+ if (!file)
+ return kstrdup("<unknown>", GFP_KERNEL);
+
+ /* We add 11 spaces for ' (deleted)' to be appended */
+ temp = kmalloc(PATH_MAX + 11, GFP_TEMPORARY);
+ if (!temp)
+ return kstrdup("<no_memory>", GFP_KERNEL);
+
+ pathname = file_path(file, temp, PATH_MAX + 11);
+ if (IS_ERR(pathname))
+ pathname = kstrdup("<too_long>", GFP_KERNEL);
+ else
+ pathname = kstrdup_quotable(pathname);
+
+ kfree(temp);
+ return pathname;
+}
+EXPORT_SYMBOL_GPL(kstrdup_quotable_file);
--
2.6.3
