diff options
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 53 |
1 files changed, 36 insertions, 17 deletions
diff --git a/fs/exec.c b/fs/exec.c index 745f6eb5279e..819643408e6d 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1115,6 +1115,17 @@ static struct file *bprm_identity_file(const struct linux_binprm *bprm) return bprm->file; } +static void posixtimer_exec(struct task_struct *me) +{ +#ifdef CONFIG_POSIX_TIMERS + spin_lock_irq(&me->sighand->siglock); + posix_cpu_timers_exit(me); + spin_unlock_irq(&me->sighand->siglock); + exit_itimers(me); + flush_itimer_signals(); +#endif +} + /* * 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 @@ -1152,6 +1163,16 @@ int begin_new_exec(struct linux_binprm * bprm) retval = de_thread(me); if (retval) goto out; + + /* + * This must be done here to ensure that POSIX CPU timers which were + * armed on the current task are dequeued from me::posix_cputimers. + * Otherwise in case of a TID switch the deletion of the related POSIX + * timer would not remove an enqueued timer because the TID lookup + * of the old TID fails. + */ + posixtimer_exec(me); + /* see the comment in check_unsafe_exec() */ current->fs->in_exec = 0; /* @@ -1165,6 +1186,20 @@ int begin_new_exec(struct linux_binprm * bprm) goto out; /* + * We have to apply CLOEXEC before we change whether the process is + * dumpable (in setup_new_exec) to avoid a race with a process in userspace + * trying to access the should-be-closed file descriptors of a process + * undergoing exec(2). + * + * This can block on filesystem ->flush() handlers, including waiting + * for FUSE daemons, so do it before exec_mmap takes the + * exec_update_lock. + * This must happen after the point of no return, and after unsharing + * the FD table. + */ + do_close_on_exec(me->files); + + /* * Must be called _before_ exec_mmap() as bprm->mm is * not visible until then. Doing it here also ensures * we don't race against replace_mm_exe_file(). @@ -1192,14 +1227,6 @@ int begin_new_exec(struct linux_binprm * bprm) if (retval) goto out_unlock; -#ifdef CONFIG_POSIX_TIMERS - spin_lock_irq(&me->sighand->siglock); - posix_cpu_timers_exit(me); - spin_unlock_irq(&me->sighand->siglock); - exit_itimers(me); - flush_itimer_signals(); -#endif - /* * Make the signal table private. */ @@ -1214,14 +1241,6 @@ int begin_new_exec(struct linux_binprm * bprm) clear_syscall_work_syscall_user_dispatch(me); - /* - * We have to apply CLOEXEC before we change whether the process is - * dumpable (in setup_new_exec) to avoid a race with a process in userspace - * trying to access the should-be-closed file descriptors of a process - * undergoing exec(2). - */ - do_close_on_exec(me->files); - if (bprm->secureexec) { /* Make sure parent cannot signal privileged process. */ me->pdeath_signal = 0; @@ -1472,9 +1491,9 @@ static void free_bprm(struct linux_binprm *bprm) /* exec swapped the mm but failed before setup_new_exec() freed it */ if (bprm->old_mm) exec_mm_put_old(bprm->old_mm); - do_close_execat(bprm->file); /* An unconsumed PT_INTERP substitute from a binfmt_misc loader entry. */ bprm_drop_loader(bprm); + do_close_execat(bprm->file); do_close_execat(bprm->executable); /* If a binfmt changed the interp, free it. */ if (bprm->interp != bprm->filename) |