Do not close file descriptors while scanning the /proc filesystem

Closing file descriptors changes the content of the fd directories in
the /proc filesystem, which means readdir() might get very confused.

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=85663

diff --git a/src/closefrom.c b/src/closefrom.c
index 27aa26f380e827eb52bcf53ba490b3cf9b2a839d..b6d983486b4456f68ce8930b84f66dc191a729cc 100644 (file)
--- a/src/closefrom.c
+++ b/src/closefrom.c
@@ -129,6 +129,10 @@ closefrom_procfs(int lowfd)
        const char *path;
        DIR *dirp;
        struct dirent *dent;
+       int *fd_array = NULL;
+       int fd_array_used = 0;
+       int fd_array_size = 0;
+       int i;
 
        /* Use /proc/self/fd (or /dev/fd on FreeBSD) if it exists. */
 # if defined(__FreeBSD__) || defined(__APPLE__)
@@ -145,10 +149,30 @@ closefrom_procfs(int lowfd)
                int fd;
 
                fd = strtonum(dent->d_name, lowfd, INT_MAX, &errstr);
-               if (errstr == NULL && fd != dirfd(dirp))
-                       closefrom_close(fd);
+               if (errstr != NULL || fd == dirfd(dirp))
+                       continue;
+
+               if (fd_array_used >= fd_array_size) {
+                       int *ptr;
+
+                       if (fd_array_size > 0)
+                               fd_array_size *= 2;
+                       else
+                               fd_array_size = 32;
+
+                       ptr = reallocarray(fd_array, fd_array_size, sizeof(int));
+                       if (ptr == NULL)
+                               break;
+                       fd_array = ptr;
+               }
+
+               fd_array[fd_array_used++] = fd;
        }
 
+       for (i = 0; i < fd_array_used; i++)
+               closefrom_close(fd_array[i]);
+
+       free(fd_array);
        (void)closedir(dirp);
 
        return 0;