Al Viro pointed out that using the phrase "close_on_exec(fd, rcu_dereference_raw(current->files->fdt))" instead of wrapping it in rcu_read_lock(), rcu_read_unlock() is a very questionable optimization[1]. Once wrapped with rcu_read_lock()/rcu_read_unlock() that phrase becomes equivalent the helper function get_close_on_exec so simplify the code and make it more robust by simply using get_close_on_exec. [1] https://lkml.kernel.org/r/20201207222214.GA4115853@xxxxxxxxxxxxxxxxxx Suggested-by: Al Viro <viro@xxxxxxxxxxxxxxxx> Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx> --- I aim to rebase my exec branch and apply this tomorrow. fs/exec.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 547a2390baf5..9aabf6e8c904 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1808,8 +1808,7 @@ static int bprm_execve(struct linux_binprm *bprm, * inaccessible after exec. Relies on having exclusive access to * current->files (due to unshare_files above). */ - if (bprm->fdpath && - close_on_exec(fd, rcu_dereference_raw(current->files->fdt))) + if (bprm->fdpath && get_close_on_exec(fd)) bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE; /* Set the unchanging part of bprm->cred */ -- 2.20.1
