Messages in this thread Patch in this message | | | From | Kees Cook <> | Subject | [PATCH v3 3/6] string_helpers: add kstrdup_quotable_file | Date | Wed, 6 Apr 2016 17:20:34 -0700 |
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Allocate a NULL-terminated file path with special characters escaped, safe for logging.
Signed-off-by: Kees Cook <keescook@chromium.org> --- v3: - add gfp_t, joe --- 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 82b3e37b9049..453378b1f58f 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, gfp_t gfp); char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp); +char *kstrdup_quotable_file(struct file *file, gfp_t gfp); #endif diff --git a/lib/string_helpers.c b/lib/string_helpers.c index 54fc860674db..a1cbb109b1a6 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> @@ -596,3 +598,31 @@ char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp) 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, gfp_t gfp) +{ + char *temp, *pathname; + + if (!file) + return kstrdup("<unknown>", gfp); + + /* We add 11 spaces for ' (deleted)' to be appended */ + temp = kmalloc(PATH_MAX + 11, GFP_TEMPORARY); + if (!temp) + return kstrdup("<no_memory>", gfp); + + pathname = file_path(file, temp, PATH_MAX + 11); + if (IS_ERR(pathname)) + pathname = kstrdup("<too_long>", gfp); + else + pathname = kstrdup_quotable(pathname, gfp); + + kfree(temp); + return pathname; +} +EXPORT_SYMBOL_GPL(kstrdup_quotable_file); -- 2.6.3
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