util.c (get_backup_sb): Check to make sure the context is passed

	in non-NULL before trying to dereference it.  Otherwise we
	might core dump when called to expand %S in a problem
	description.

diff --git a/e2fsck/ChangeLog b/e2fsck/ChangeLog
index 11df40f..b5b9efa 100644 (file)
--- a/e2fsck/ChangeLog
+++ b/e2fsck/ChangeLog
@@ -1,5 +1,10 @@
 2003-08-24  Theodore Ts'o  <tytso@mit.edu>
 
+       * util.c (get_backup_sb): Check to make sure the context is passed
+               in non-NULL before trying to dereference it.  Otherwise we
+               might core dump when called to expand %S in a problem
+               description.
+
        * e2fsck.8.in: Adjust description line so that apropos
                "ext2" or "ext3" will find the man page.  (Addresses
                Debian Bug #206845)

diff --git a/e2fsck/util.c b/e2fsck/util.c
index 2c890dc..8bb538d 100644 (file)
--- a/e2fsck/util.c
+++ b/e2fsck/util.c
@@ -439,8 +439,11 @@ blk_t get_backup_sb(e2fsck_t ctx, ext2_filsys fs, const char *name,
                        ext2fs_swap_super(sb);
 #endif
                if (sb->s_magic == EXT2_SUPER_MAGIC) {
-                       ret_sb = ctx->superblock = superblock;
-                       ctx->blocksize = blocksize;
+                       ret_sb = superblock;
+                       if (ctx) {
+                               ctx->superblock = superblock;
+                               ctx->blocksize = blocksize;
+                       }
                        break;
                }
        }