diff options
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/fs/exec.c b/fs/exec.c index f45859ad13ac..5d1c0d2dc403 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1227,13 +1227,12 @@ int begin_new_exec(struct linux_binprm * bprm) */ bprm->point_of_no_return = true; - /* - * Make this the only thread in the thread group. - */ + /* Make this the only thread in the thread group */ retval = de_thread(me); if (retval) goto out; - + /* see the comment in check_unsafe_exec() */ + current->fs->in_exec = 0; /* * Cancel any io_uring activity across execve */ @@ -1495,6 +1494,8 @@ static void free_bprm(struct linux_binprm *bprm) } free_arg_pages(bprm); if (bprm->cred) { + /* in case exec fails before de_thread() succeeds */ + current->fs->in_exec = 0; mutex_unlock(¤t->signal->cred_guard_mutex); abort_creds(bprm->cred); } @@ -1616,6 +1617,10 @@ static void check_unsafe_exec(struct linux_binprm *bprm) * suid exec because the differently privileged task * will be able to manipulate the current directory, etc. * It would be nice to force an unshare instead... + * + * Otherwise we set fs->in_exec = 1 to deny clone(CLONE_FS) + * from another sub-thread until de_thread() succeeds, this + * state is protected by cred_guard_mutex we hold. */ n_fs = 1; spin_lock(&p->fs->lock); @@ -1860,7 +1865,6 @@ static int bprm_execve(struct linux_binprm *bprm) sched_mm_cid_after_execve(current); /* execve succeeded */ - current->fs->in_exec = 0; current->in_execve = 0; rseq_execve(current); user_events_execve(current); @@ -1879,7 +1883,6 @@ out: force_fatal_sig(SIGSEGV); sched_mm_cid_after_execve(current); - current->fs->in_exec = 0; current->in_execve = 0; return retval; |