diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2009-06-12 09:53:47 +0200 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2009-06-12 11:32:58 +0200 |
| commit | 5b02ee3d219f9e01b6e9146e25613822cfc2e5ce (patch) | |
| tree | 7ce9126738c3cf4b37d67170d0e4b34818c057a9 /security/commoncap.c | |
| parent | 26a28fa4fea5b8c65713aa50c124f76a88c7924d (diff) | |
| parent | 8ebf975608aaebd7feb33d77f07ba21a6380e086 (diff) | |
| download | lwn-5b02ee3d219f9e01b6e9146e25613822cfc2e5ce.tar.gz lwn-5b02ee3d219f9e01b6e9146e25613822cfc2e5ce.zip | |
asm-generic: merge branch 'master' of torvalds/linux-2.6
Fixes a merge conflict against the x86 tree caused by a fix to
atomic.h which I renamed to atomic_long.h.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'security/commoncap.c')
| -rw-r--r-- | security/commoncap.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/security/commoncap.c b/security/commoncap.c index beac0258c2a8..48b7e0228fa3 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -28,6 +28,28 @@ #include <linux/prctl.h> #include <linux/securebits.h> +/* + * If a non-root user executes a setuid-root binary in + * !secure(SECURE_NOROOT) mode, then we raise capabilities. + * However if fE is also set, then the intent is for only + * the file capabilities to be applied, and the setuid-root + * bit is left on either to change the uid (plausible) or + * to get full privilege on a kernel without file capabilities + * support. So in that case we do not raise capabilities. + * + * Warn if that happens, once per boot. + */ +static void warn_setuid_and_fcaps_mixed(char *fname) +{ + static int warned; + if (!warned) { + printk(KERN_INFO "warning: `%s' has both setuid-root and" + " effective capabilities. Therefore not raising all" + " capabilities.\n", fname); + warned = 1; + } +} + int cap_netlink_send(struct sock *sk, struct sk_buff *skb) { NETLINK_CB(skb).eff_cap = current_cap(); @@ -464,6 +486,15 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) if (!issecure(SECURE_NOROOT)) { /* + * If the legacy file capability is set, then don't set privs + * for a setuid root binary run by a non-root user. Do set it + * for a root user just to cause least surprise to an admin. + */ + if (effective && new->uid != 0 && new->euid == 0) { + warn_setuid_and_fcaps_mixed(bprm->filename); + goto skip; + } + /* * To support inheritance of root-permissions and suid-root * executables under compatibility mode, we override the * capability sets for the file. @@ -478,6 +509,7 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) if (new->euid == 0) effective = true; } +skip: /* Don't let someone trace a set[ug]id/setpcap binary with the revised * credentials unless they have the appropriate permit |