[xen stable-4.18] tools/libxs: Open /dev/xen/xenbus fds as O_CLOEXEC

[patchbot@xxxxxxx]

commit 2bc52041cacb33a301ebf939d69a021597941186
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Tue May 21 10:21:47 2024 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue May 21 10:21:47 2024 +0200

    tools/libxs: Open /dev/xen/xenbus fds as O_CLOEXEC
    
    The header description for xs_open() goes as far as to suggest that the fd 
is
    O_CLOEXEC, but it isn't actually.
    
    `xl devd` has been observed leaking /dev/xen/xenbus into children.
    
    Link: https://github.com/QubesOS/qubes-issues/issues/8292
    Reported-by: Demi Marie Obenour <demi@xxxxxxxxxxxxxxxxxxxxxx>
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
    master commit: f4f2f3402b2f4985d69ffc0d46f845d05fd0b60f
    master date: 2024-05-07 15:18:36 +0100
---
 tools/libs/store/xs.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/libs/store/xs.c b/tools/libs/store/xs.c
index 140b9a2839..1498515073 100644
--- a/tools/libs/store/xs.c
+++ b/tools/libs/store/xs.c
@@ -54,6 +54,10 @@ struct xs_stored_msg {
 #include <dlfcn.h>
 #endif
 
+#ifndef O_CLOEXEC
+#define O_CLOEXEC 0
+#endif
+
 struct xs_handle {
        /* Communications channel to xenstore daemon. */
        int fd;
@@ -227,7 +231,7 @@ error:
 static int get_dev(const char *connect_to)
 {
        /* We cannot open read-only because requests are writes */
-       return open(connect_to, O_RDWR);
+       return open(connect_to, O_RDWR | O_CLOEXEC);
 }
 
 static int all_restrict_cb(Xentoolcore__Active_Handle *ah, domid_t domid) {
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.18