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Commit 098c5eea authored by Andreas Gruenbacher's avatar Andreas Gruenbacher Committed by Linus Torvalds
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[PATCH] null-terminate over-long /proc/kallsyms symbols 

Got a customer bug report (https://bugzilla.novell.com/190296

) about kernel
symbols longer than 127 characters which end up in a string buffer that is
not NULL terminated, leading to garbage in /proc/kallsyms.  Using strlcpy
prevents this from happening, even though such symbols still won't come out
right.

A better fix would be to not use a fixed-size buffer, but it's probably not
worth the trouble.  (Modversion'ed symbols even have a length limit of 60.)

[bunk@stusta.de: build fix]
Signed-off-by: default avatarAndreas Gruenbacher <agruen@suse.de>
Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 329c6e42

include/linux/module.h

+4 −6
Original line number Diff line number Diff line
@@ -362,10 +362,8 @@ int is_module_address(unsigned long addr); 


/* Returns module and fills in value, defined and namebuf, or NULL if

   symnum out of range. */

struct module *module_get_kallsym(unsigned int symnum,

				  unsigned long *value,

				  char *type,

				  char namebuf[128]);

struct module *module_get_kallsym(unsigned int symnum, unsigned long *value,

				char *type, char *name, size_t namelen);



/* Look for this name: can be of form module:name. */

unsigned long module_kallsyms_lookup_name(const char *name);
@@ -535,8 +533,8 @@ static inline const char *module_address_lookup(unsigned long addr, 


static inline struct module *module_get_kallsym(unsigned int symnum,

						unsigned long *value,

						char *type,

						char namebuf[128])

						char *type, char *name,

						size_t namelen)

{

	return NULL;

}

kernel/kallsyms.c

+2 −2
Original line number Diff line number Diff line
@@ -275,8 +275,8 @@ static void upcase_if_global(struct kallsym_iter *iter) 
static int get_ksymbol_mod(struct kallsym_iter *iter)

{

	iter->owner = module_get_kallsym(iter->pos - kallsyms_num_syms,

					 &iter->value,

					 &iter->type, iter->name);

					 &iter->value, &iter->type,

					 iter->name, sizeof(iter->name));

	if (iter->owner == NULL)

		return 0;

kernel/module.c

+4 −7
Original line number Diff line number Diff line
@@ -2019,10 +2019,8 @@ const char *module_address_lookup(unsigned long addr, 
	return NULL;

}



struct module *module_get_kallsym(unsigned int symnum,

				  unsigned long *value,

				  char *type,

				  char namebuf[128])

struct module *module_get_kallsym(unsigned int symnum, unsigned long *value,

				char *type, char *name, size_t namelen)

{

	struct module *mod;
@@ -2031,9 +2029,8 @@ struct module *module_get_kallsym(unsigned int symnum, 
		if (symnum < mod->num_symtab) {

			*value = mod->symtab[symnum].st_value;

			*type = mod->symtab[symnum].st_info;

			strncpy(namebuf,

				mod->strtab + mod->symtab[symnum].st_name,

				127);

			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,

				namelen);

			mutex_unlock(&module_mutex);

			return mod;

		}