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authorOleg Nesterov <oleg@redhat.com>2010-05-26 14:43:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-27 09:12:45 -0700
commit685bfd2c48bb3284d31e73ff3151c957d76deda9 (patch)
tree177210787515f48c0eaad5216bd012f4a2fb2149
parentexec: replace call_usermodehelper_pipe with use of umh init function and resolve limit (diff)
downloadlinux-dev-685bfd2c48bb3284d31e73ff3151c957d76deda9.tar.xz
linux-dev-685bfd2c48bb3284d31e73ff3151c957d76deda9.zip
umh: creds: convert call_usermodehelper_keys() to use subprocess_info->init()
call_usermodehelper_keys() uses call_usermodehelper_setkeys() to change subprocess_info->cred in advance. Now that we have info->init() we can change this code to set tgcred->session_keyring in context of execing kernel thread. Note: since currently call_usermodehelper_keys() is never called with UMH_NO_WAIT, call_usermodehelper_keys()->key_get() and umh_keys_cleanup() are not really needed, we could rely on install_session_keyring_to_cred() which does key_get() on success. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/kmod.h17
-rw-r--r--kernel/kmod.c18
-rw-r--r--security/keys/internal.h1
-rw-r--r--security/keys/process_keys.c3
-rw-r--r--security/keys/request_key.c32
5 files changed, 34 insertions, 37 deletions
diff --git a/include/linux/kmod.h b/include/linux/kmod.h
index 5c058778ad35..d876dce217f0 100644
--- a/include/linux/kmod.h
+++ b/include/linux/kmod.h
@@ -72,8 +72,6 @@ struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
char **envp, gfp_t gfp_mask);
/* Set various pieces of state into the subprocess_info structure */
-void call_usermodehelper_setkeys(struct subprocess_info *info,
- struct key *session_keyring);
void call_usermodehelper_setfns(struct subprocess_info *info,
int (*init)(struct subprocess_info *info),
void (*cleanup)(struct subprocess_info *info),
@@ -112,21 +110,6 @@ call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait)
NULL, NULL, NULL);
}
-static inline int
-call_usermodehelper_keys(char *path, char **argv, char **envp,
- struct key *session_keyring, enum umh_wait wait)
-{
- struct subprocess_info *info;
- gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
-
- info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
- if (info == NULL)
- return -ENOMEM;
-
- call_usermodehelper_setkeys(info, session_keyring);
- return call_usermodehelper_exec(info, wait);
-}
-
extern void usermodehelper_init(void);
extern int usermodehelper_disable(void);
diff --git a/kernel/kmod.c b/kernel/kmod.c
index d1544547fea6..743d3883517c 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -367,24 +367,6 @@ struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
EXPORT_SYMBOL(call_usermodehelper_setup);
/**
- * call_usermodehelper_setkeys - set the session keys for usermode helper
- * @info: a subprocess_info returned by call_usermodehelper_setup
- * @session_keyring: the session keyring for the process
- */
-void call_usermodehelper_setkeys(struct subprocess_info *info,
- struct key *session_keyring)
-{
-#ifdef CONFIG_KEYS
- struct thread_group_cred *tgcred = info->cred->tgcred;
- key_put(tgcred->session_keyring);
- tgcred->session_keyring = key_get(session_keyring);
-#else
- BUG();
-#endif
-}
-EXPORT_SYMBOL(call_usermodehelper_setkeys);
-
-/**
* call_usermodehelper_setfns - set a cleanup/init function
* @info: a subprocess_info returned by call_usermodehelper_setup
* @cleanup: a cleanup function
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 5d4402a1161a..38783dcf6c61 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -124,6 +124,7 @@ extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
extern int install_user_keyrings(void);
extern int install_thread_keyring_to_cred(struct cred *);
extern int install_process_keyring_to_cred(struct cred *);
+extern int install_session_keyring_to_cred(struct cred *, struct key *);
extern struct key *request_key_and_link(struct key_type *type,
const char *description,
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 20a38fed61b1..6b8e4ff4cc68 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -216,8 +216,7 @@ static int install_process_keyring(void)
/*
* install a session keyring directly to a credentials struct
*/
-static int install_session_keyring_to_cred(struct cred *cred,
- struct key *keyring)
+int install_session_keyring_to_cred(struct cred *cred, struct key *keyring)
{
unsigned long flags;
struct key *old;
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index f656e9c069e3..f5ec9ac5d57c 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -58,6 +58,38 @@ void complete_request_key(struct key_construction *cons, int error)
}
EXPORT_SYMBOL(complete_request_key);
+static int umh_keys_init(struct subprocess_info *info)
+{
+ struct cred *cred = (struct cred*)current_cred();
+ struct key *keyring = info->data;
+ /*
+ * This is called in context of freshly forked kthread before
+ * kernel_execve(), we can just change our ->session_keyring.
+ */
+ return install_session_keyring_to_cred(cred, keyring);
+}
+
+static void umh_keys_cleanup(struct subprocess_info *info)
+{
+ struct key *keyring = info->data;
+ key_put(keyring);
+}
+
+static int call_usermodehelper_keys(char *path, char **argv, char **envp,
+ struct key *session_keyring, enum umh_wait wait)
+{
+ gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
+ struct subprocess_info *info =
+ call_usermodehelper_setup(path, argv, envp, gfp_mask);
+
+ if (!info)
+ return -ENOMEM;
+
+ call_usermodehelper_setfns(info, umh_keys_init, umh_keys_cleanup,
+ key_get(session_keyring));
+ return call_usermodehelper_exec(info, wait);
+}
+
/*
* request userspace finish the construction of a key
* - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>"