From 4587f99cc2c87079167b18e284f64b66cafade76 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Mon, 21 Sep 2026 16:15:36 +0200 Subject: file: let dup_fd() drop only close-on-exec descriptors Add FD_RANGE_CLOEXEC_ONLY. When set dup_fd() leaves everything behind except for fds that are close-on-exec. Without FD_RANGE_EXCEPT the clone loses the close-on-exec descriptors in the range. With it the clone keeps the range and loses the close-on-exec descriptors everywhere else. Descriptors without the flag are carried over either way. Nothing passes the flag yet. Link: https://patch.msgid.link/20260921-work-file-close_range_except-v1-8-c20d0b49270d@kernel.org Reviewed-by: Jann Horn Signed-off-by: Christian Brauner (Amutable) --- include/linux/fdtable.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index d6c6c7a3400d..afdfaad381df 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -104,6 +104,9 @@ int unshare_files(void); enum fd_range_flags { /* Leave behind all descriptors outside of the specified range. */ FD_RANGE_EXCEPT = (1U << 0), + + /* Only select descriptors that have close-on-exec set. */ + FD_RANGE_CLOEXEC_ONLY = (1U << 1), }; struct fd_range { -- cgit v1.2.3