src/fill2: fix segfault during fopen error cleanup

When fill2 fails to open the output file (e.g. due to ENOSPC), it jumps
into the cleanup code where it attempts to call fclose, and this causes
a segfault within the glibc fclose code as it attempts to deref a null
pointer.

Fix it by conditionally calling fclose on the file pointer only when
non-null.

This is consistently reproducible with xfs/041.

Signed-off-by: Anthony Iliopoulos <ailiop@suse.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Zorro Lang <zlang@kernel.org>

diff --git a/src/fill2.c b/src/fill2.c
index 4cc1c3d79a98b9286ba1dd1d8750349e3d88548d..37ed00b1d9b165b63fe19938d67c34e1de52670a 100644 (file)
--- a/src/fill2.c
+++ b/src/fill2.c
@@ -307,7 +307,7 @@ main(int argc, char **argv)
  cleanup:
 
     /* close file and flush buffers - check if this fails */
-    if (fclose(f) != 0) {
+    if (f && fclose(f) != 0) {
        fprintf(stderr, "fill2: fclose() on \"%s\" failed: %s\n",
                dfile, strerror(errno));
        status = 1;