diff options
| -rw-r--r-- | fs/exec.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/fs/exec.c b/fs/exec.c index a0fff86269e4..26b98072be50 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1259,6 +1259,12 @@ void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec) perf_event_comm(tsk, exec); } +/* + * Calling this is the point of no return. None of the failures will be + * seen by userspace since either the process is already taking a fatal + * signal (via de_thread() or coredump), or will have SEGV raised + * (after exec_mmap()) by search_binary_handlers (see below). + */ int flush_old_exec(struct linux_binprm * bprm) { int retval; @@ -1286,7 +1292,13 @@ int flush_old_exec(struct linux_binprm * bprm) if (retval) goto out; - bprm->mm = NULL; /* We're using it now */ + /* + * After clearing bprm->mm (to mark that current is using the + * prepared mm now), we have nothing left of the original + * process. If anything from here on returns an error, the check + * in search_binary_handler() will SEGV current. + */ + bprm->mm = NULL; set_fs(USER_DS); current->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | @@ -1333,7 +1345,6 @@ void setup_new_exec(struct linux_binprm * bprm) { arch_pick_mmap_layout(current->mm); - /* This is the point of no return */ current->sas_ss_sp = current->sas_ss_size = 0; if (uid_eq(current_euid(), current_uid()) && gid_eq(current_egid(), current_gid())) @@ -1351,7 +1362,6 @@ void setup_new_exec(struct linux_binprm * bprm) */ current->mm->task_size = TASK_SIZE; - /* install the new credentials */ if (!uid_eq(bprm->cred->uid, current_euid()) || !gid_eq(bprm->cred->gid, current_egid())) { current->pdeath_signal = 0; |