strcpy() is deprecated and sprintf() does not perform bounds checking either. Although an overflow is unlikely, it's better to proactively avoid it by using the safer strscpy() and scnprintf(), respectively.
Additionally, unify memory allocation for 'hname' to simplify and improve aa_policy_init(). Link: https://github.com/KSPP/linux/issues/88 Signed-off-by: Thorsten Blum <[email protected]> --- security/apparmor/lib.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/security/apparmor/lib.c b/security/apparmor/lib.c index 82dbb97ad406..acf7f5189bec 100644 --- a/security/apparmor/lib.c +++ b/security/apparmor/lib.c @@ -478,19 +478,17 @@ bool aa_policy_init(struct aa_policy *policy, const char *prefix, const char *name, gfp_t gfp) { char *hname; + size_t hname_sz; + hname_sz = (prefix ? strlen(prefix) + 2 : 0) + strlen(name) + 1; /* freed by policy_free */ - if (prefix) { - hname = aa_str_alloc(strlen(prefix) + strlen(name) + 3, gfp); - if (hname) - sprintf(hname, "%s//%s", prefix, name); - } else { - hname = aa_str_alloc(strlen(name) + 1, gfp); - if (hname) - strcpy(hname, name); - } + hname = aa_str_alloc(hname_sz, gfp); if (!hname) return false; + if (prefix) + scnprintf(hname, hname_sz, "%s//%s", prefix, name); + else + strscpy(hname, name, hname_sz); policy->hname = hname; /* base.name is a substring of fqname */ policy->name = basename(policy->hname); -- 2.51.0
