diff options
Diffstat (limited to 'security/keys/process_keys.c')
| -rw-r--r-- | security/keys/process_keys.c | 69 |
1 files changed, 63 insertions, 6 deletions
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 276d27882ce8..5c23afb31ece 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -17,6 +17,7 @@ #include <linux/fs.h> #include <linux/err.h> #include <linux/mutex.h> +#include <linux/security.h> #include <linux/user_namespace.h> #include <asm/uaccess.h> #include "internal.h" @@ -487,7 +488,7 @@ static int lookup_user_key_possessed(const struct key *key, const void *target) * - don't create special keyrings unless so requested * - partially constructed keys aren't found unless requested */ -key_ref_t lookup_user_key(key_serial_t id, int create, int partial, +key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags, key_perm_t perm) { struct request_key_auth *rka; @@ -503,7 +504,7 @@ try_again: switch (id) { case KEY_SPEC_THREAD_KEYRING: if (!cred->thread_keyring) { - if (!create) + if (!(lflags & KEY_LOOKUP_CREATE)) goto error; ret = install_thread_keyring(); @@ -521,7 +522,7 @@ try_again: case KEY_SPEC_PROCESS_KEYRING: if (!cred->tgcred->process_keyring) { - if (!create) + if (!(lflags & KEY_LOOKUP_CREATE)) goto error; ret = install_process_keyring(); @@ -642,7 +643,14 @@ try_again: break; } - if (!partial) { + /* unlink does not use the nominated key in any way, so can skip all + * the permission checks as it is only concerned with the keyring */ + if (lflags & KEY_LOOKUP_FOR_UNLINK) { + ret = 0; + goto error; + } + + if (!(lflags & KEY_LOOKUP_PARTIAL)) { ret = wait_for_key_construction(key, true); switch (ret) { case -ERESTARTSYS: @@ -660,7 +668,8 @@ try_again: } ret = -EIO; - if (!partial && !test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) + if (!(lflags & KEY_LOOKUP_PARTIAL) && + !test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) goto invalid_key; /* check the permissions */ @@ -702,7 +711,7 @@ long join_session_keyring(const char *name) /* only permit this if there's a single thread in the thread group - * this avoids us having to adjust the creds on all threads and risking * ENOMEM */ - if (!is_single_threaded(current)) + if (!current_is_single_threaded()) return -EMLINK; new = prepare_creds(); @@ -760,3 +769,51 @@ error: abort_creds(new); return ret; } + +/* + * Replace a process's session keyring when that process resumes userspace on + * behalf of one of its children + */ +void key_replace_session_keyring(void) +{ + const struct cred *old; + struct cred *new; + + if (!current->replacement_session_keyring) + return; + + write_lock_irq(&tasklist_lock); + new = current->replacement_session_keyring; + current->replacement_session_keyring = NULL; + write_unlock_irq(&tasklist_lock); + + if (!new) + return; + + old = current_cred(); + new-> uid = old-> uid; + new-> euid = old-> euid; + new-> suid = old-> suid; + new->fsuid = old->fsuid; + new-> gid = old-> gid; + new-> egid = old-> egid; + new-> sgid = old-> sgid; + new->fsgid = old->fsgid; + new->user = get_uid(old->user); + new->group_info = get_group_info(old->group_info); + + new->securebits = old->securebits; + new->cap_inheritable = old->cap_inheritable; + new->cap_permitted = old->cap_permitted; + new->cap_effective = old->cap_effective; + new->cap_bset = old->cap_bset; + + new->jit_keyring = old->jit_keyring; + new->thread_keyring = key_get(old->thread_keyring); + new->tgcred->tgid = old->tgcred->tgid; + new->tgcred->process_keyring = key_get(old->tgcred->process_keyring); + + security_transfer_creds(new, old); + + commit_creds(new); +} |