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-rw-r--r--fs/exec.c7
-rw-r--r--include/linux/binfmts.h7
-rw-r--r--include/linux/security.h3
-rw-r--r--security/commoncap.c12
4 files changed, 23 insertions, 6 deletions
diff --git a/fs/exec.c b/fs/exec.c
index 0f361115c88f..1536bc4502cc 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1345,6 +1345,13 @@ void setup_new_exec(struct linux_binprm * bprm)
{
bprm->secureexec |= security_bprm_secureexec(bprm);
+ /*
+ * Once here, prepare_binrpm() will not be called any more, so
+ * the final state of setuid/setgid/fscaps can be merged into the
+ * secureexec flag.
+ */
+ bprm->secureexec |= bprm->cap_elevated;
+
arch_pick_mmap_layout(current->mm);
current->sas_ss_sp = current->sas_ss_size = 0;
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index 16838ba7ee75..213c61fa3780 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -35,6 +35,13 @@ struct linux_binprm {
* false if not; except for init which inherits
* its parent's caps anyway */
/*
+ * True if most recent call to the commoncaps bprm_set_creds
+ * hook (due to multiple prepare_binprm() calls from the
+ * binfmt_script/misc handlers) resulted in elevated
+ * privileges.
+ */
+ cap_elevated:1,
+ /*
* Set by bprm_set_creds hook to indicate a privilege-gaining
* exec has happened. Used to sanitize execution environment
* and to set AT_SECURE auxv for glibc.
diff --git a/include/linux/security.h b/include/linux/security.h
index b6ea1dc9cc9d..f89832ccdf55 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -85,7 +85,6 @@ extern int cap_capset(struct cred *new, const struct cred *old,
const kernel_cap_t *inheritable,
const kernel_cap_t *permitted);
extern int cap_bprm_set_creds(struct linux_binprm *bprm);
-extern int cap_bprm_secureexec(struct linux_binprm *bprm);
extern int cap_inode_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags);
extern int cap_inode_removexattr(struct dentry *dentry, const char *name);
@@ -543,7 +542,7 @@ static inline void security_bprm_committed_creds(struct linux_binprm *bprm)
static inline int security_bprm_secureexec(struct linux_binprm *bprm)
{
- return cap_bprm_secureexec(bprm);
+ return 0;
}
static inline int security_sb_alloc(struct super_block *sb)
diff --git a/security/commoncap.c b/security/commoncap.c
index 7abebd782d5e..abb6050c8083 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -481,6 +481,8 @@ out:
return rc;
}
+static int is_secureexec(struct linux_binprm *bprm);
+
/**
* cap_bprm_set_creds - Set up the proposed credentials for execve().
* @bprm: The execution parameters, including the proposed creds
@@ -614,11 +616,14 @@ skip:
if (WARN_ON(!cap_ambient_invariant_ok(new)))
return -EPERM;
+ /* Check for privilege-elevated exec. */
+ bprm->cap_elevated = is_secureexec(bprm);
+
return 0;
}
/**
- * cap_bprm_secureexec - Determine whether a secure execution is required
+ * is_secureexec - Determine whether a secure execution is required
* @bprm: The execution parameters
*
* Determine whether a secure execution is required, return 1 if it is, and 0
@@ -627,9 +632,9 @@ skip:
* The credentials have been committed by this point, and so are no longer
* available through @bprm->cred.
*/
-int cap_bprm_secureexec(struct linux_binprm *bprm)
+static int is_secureexec(struct linux_binprm *bprm)
{
- const struct cred *cred = current_cred();
+ const struct cred *cred = bprm->cred;
kuid_t root_uid = make_kuid(cred->user_ns, 0);
if (!uid_eq(cred->uid, root_uid)) {
@@ -1079,7 +1084,6 @@ struct security_hook_list capability_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(capget, cap_capget),
LSM_HOOK_INIT(capset, cap_capset),
LSM_HOOK_INIT(bprm_set_creds, cap_bprm_set_creds),
- LSM_HOOK_INIT(bprm_secureexec, cap_bprm_secureexec),
LSM_HOOK_INIT(inode_need_killpriv, cap_inode_need_killpriv),
LSM_HOOK_INIT(inode_killpriv, cap_inode_killpriv),
LSM_HOOK_INIT(mmap_addr, cap_mmap_addr),