Messages in this thread Patch in this message | | | From | Mathias Krause <> | Subject | [PATCH] module: don't modify argument of module_kallsyms_lookup_name() | Date | Wed, 12 Jun 2013 19:29:41 +0200 |
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If we pass a pointer to a const string of the form "module:symbol" module_kallsyms_lookup_name() will try to split the string at the colon, i.e., will try to modify r/o data. That will, in fact, fail on a kernel with enabled CONFIG_DEBUG_RODATA.
Avoid modifying the string passed as argument and operate on a copy instead in case we need to split the string.
Signed-off-by: Mathias Krause <minipli@googlemail.com> --- kernel/module.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/kernel/module.c b/kernel/module.c index cab4bce..5ce0784 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3557,16 +3557,17 @@ static unsigned long mod_find_symname(struct module *mod, const char *name) unsigned long module_kallsyms_lookup_name(const char *name) { struct module *mod; - char *colon; + char *colon, *mod_name; unsigned long ret = 0; /* Don't lock: we're in enough trouble already. */ preempt_disable(); if ((colon = strchr(name, ':')) != NULL) { - *colon = '\0'; - if ((mod = find_module(name)) != NULL) + mod_name = kstrndup(name, colon - name, GFP_ATOMIC); + if (mod_name && (mod = find_module(mod_name)) != NULL) { ret = mod_find_symname(mod, colon+1); - *colon = ':'; + kfree(mod_name); + } } else { list_for_each_entry_rcu(mod, &modules, list) { if (mod->state == MODULE_STATE_UNFORMED) -- 1.7.10.4
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