1 files changed, 51 insertions, 4 deletions

diff --git a/lib/zlib_inflate/inflate.c b/lib/zlib_inflate/inflate.c
index 7e1e3114a73e..0ad1ebf00947 100644
--- a/lib/zlib_inflate/inflate.c
+++ b/lib/zlib_inflate/inflate.c
@@ -332,14 +332,14 @@ static int zlib_inflateSyncPacket(z_streamp strm)
 int zlib_inflate(z_streamp strm, int flush)
 {
     struct inflate_state *state;
-    unsigned char *next;    /* next input */
-    unsigned char *put;     /* next output */
+    const unsigned char *next;  /* next input */
+    unsigned char *put;         /* next output */
     unsigned have, left;        /* available input and output */
     unsigned long hold;         /* bit buffer */
     unsigned bits;              /* bits in bit buffer */
     unsigned in, out;           /* save starting available input and output */
     unsigned copy;              /* number of stored or match bytes to copy */
-    unsigned char *from;    /* where to copy match bytes from */
+    unsigned char *from;        /* where to copy match bytes from */
     code this;                  /* current decoding table entry */
     code last;                  /* parent table entry */
     unsigned len;               /* length to copy for repeats, bits to drop */
@@ -897,7 +897,7 @@ int zlib_inflateIncomp(z_stream *z)
 
     /* Setup some variables to allow misuse of updateWindow */
     z->avail_out = 0;
-    z->next_out = z->next_in + z->avail_in;
+    z->next_out = (unsigned char*)z->next_in + z->avail_in;
 
     zlib_updatewindow(z, z->avail_in);
 
@@ -916,3 +916,50 @@ int zlib_inflateIncomp(z_stream *z)
 
     return Z_OK;
 }
+
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+/* Utility function: initialize zlib, unpack binary blob, clean up zlib,
+ * return len or negative error code. */
+int zlib_inflate_blob(void *gunzip_buf, unsigned sz, const void *buf, unsigned len)
+{
+        const u8 *zbuf = buf;
+        struct z_stream_s *strm;
+        int rc;
+
+        rc = -ENOMEM;
+        strm = kmalloc(sizeof(*strm), GFP_KERNEL);
+        if (strm == NULL)
+                goto gunzip_nomem1;
+        strm->workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
+        if (strm->workspace == NULL)
+                goto gunzip_nomem2;
+
+        /* gzip header (1f,8b,08... 10 bytes total + possible asciz filename)
+         * expected to be stripped from input */
+
+        strm->next_in = zbuf;
+        strm->avail_in = len;
+        strm->next_out = gunzip_buf;
+        strm->avail_out = sz;
+
+        rc = zlib_inflateInit2(strm, -MAX_WBITS);
+        if (rc == Z_OK) {
+                rc = zlib_inflate(strm, Z_FINISH);
+                /* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */
+                if (rc == Z_STREAM_END)
+                        rc = sz - strm->avail_out;
+                else
+                        rc = -EINVAL;
+                zlib_inflateEnd(strm);
+        } else
+                rc = -EINVAL;
+
+        kfree(strm->workspace);
+gunzip_nomem2:
+        kfree(strm);
+gunzip_nomem1:
+        return rc; /* returns Z_OK (0) if successful */
+}