xz: Capsicum sandbox: Fix incorrect use of cap_rights_clear()

cap_rights_clear() with no additional arguments acts as a no-op, so
instead of removing all capability rights from STDIN_FILENO, the same
rights were allowed for STDIN_FILENO as were allowed for src_fd.

Co-authored-by: Guillaume Outters <guillaume-installs@outters.eu>
Fixes: fd56d5353360 ("xz: Make Capsicum sandbox more strict with stdin and stdout.")
(The commit message says "stdout". It should have said "stderr".)

(based on commit 5cc2e479eb447a444f5ab005fc36b7f275c75eb5)

diff --git a/src/xz/file_io.c b/src/xz/file_io.c
index 78fbdf724eea1d4e19fdf744fe0d1b14c8979827..f09498da892a6a17293d09b947ed913d2ca3afad 100644 (file)
--- a/src/xz/file_io.c
+++ b/src/xz/file_io.c
@@ -201,7 +201,7 @@ io_sandbox_enter(int src_fd)
 
        // If not reading from stdin, remove all capabilities from it.
        if (src_fd != STDIN_FILENO && cap_rights_limit(
-                       STDIN_FILENO, cap_rights_clear(&rights)))
+                       STDIN_FILENO, cap_rights_init(&rights)))
                goto error;
 
        if (cap_rights_limit(STDOUT_FILENO, cap_rights_init(&rights,