[PATCH] initramfs: fix CPIO hardlink check

From: Mark Huang
Date: Thu May 04 2006 - 14:45:00 EST


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@xxxxxxxxxxxxxxxx>

--- 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;

-
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