[PATCH] initramfs: fix CPIO hardlink check

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.

Signed-off-by: Mark Huang <mlhuang@cs.princeton.edu>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/init/initramfs.c b/init/initramfs.c
index 679d870d991b760438a95d133c9684b9f381eb0d..f81cfa40a719858a003ab50448f3d0925005d5ff 100644 (file)
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -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, int minor, int ino, char *name)
        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;