[PATCH] initramfs: fix CPIO hardlink check

[PATCH] initramfs: fix CPIO hardlink check

[Mark Huang]

Copy the filenames of hardlinks when inserting them into the hash, since
the "name" pointer may point to scratch space (name_buf). Not doing so
results in corruption if the scratch space is later overwritten: the 
wrong file may be hardlinked, or, if the scratch space contains garbage, 
the link will fail and a 0-byte file will be created instead.

Cc: me on responses.

Signed-off-by: Mark Huang <mlhuang@cs.princeton.edu>

--- linux-2.6.16.13/init/initramfs.c	2006-05-02 17:38:44.000000000 -0400
+++ linux-2.6.16.13.initramfs/init/initramfs.c	2006-05-04 
14:26:44.000000000 -0400
@@ -26,10 +26,12 @@ static void __init free(void *where)

  /* link hash */

+#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
+
  static __initdata struct hash {
  	int ino, minor, major;
  	struct hash *next;
-	char *name;
+	char name[N_ALIGN(PATH_MAX)];
  } *head[32];

  static inline int hash(int major, int minor, int ino)
@@ -57,7 +59,7 @@ static char __init *find_link(int major,
  	q->ino = ino;
  	q->minor = minor;
  	q->major = major;
-	q->name = name;
+	strcpy(q->name, name);
  	q->next = NULL;
  	*p = q;
  	return NULL;
@@ -133,8 +135,6 @@ static inline void eat(unsigned n)
  	count -= n;
  }

-#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
-
  static __initdata char *collected;
  static __initdata int remains;
  static __initdata char *collect;