[PARISC] Fix fs/binfmt_som.c

Fix compilation (missing include of a.out.h)
Fix security hole (need to call unshare_files)

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

1 files changed, 16 insertions, 2 deletions

diff --git a/fs/binfmt_som.c b/fs/binfmt_som.c
index 32b5d625ce9c..5bcdaaf4eae0 100644
--- a/fs/binfmt_som.c
+++ b/fs/binfmt_som.c
@@ -29,6 +29,7 @@
 #include <linux/personality.h>
 #include <linux/init.h>
 
+#include <asm/a.out.h>
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
 
@@ -194,6 +195,7 @@ load_som_binary(struct linux_binprm * bprm, struct pt_regs * regs)
         unsigned long som_entry;
         struct som_hdr *som_ex;
         struct som_exec_auxhdr *hpuxhdr;
+        struct files_struct *files;
 
         /* Get the exec-header */
         som_ex = (struct som_hdr *) bprm->buf;
@@ -208,15 +210,27 @@ load_som_binary(struct linux_binprm * bprm, struct pt_regs * regs)
         size = som_ex->aux_header_size;
         if (size > SOM_PAGESIZE)
                 goto out;
-        hpuxhdr = (struct som_exec_auxhdr *) kmalloc(size, GFP_KERNEL);
+        hpuxhdr = kmalloc(size, GFP_KERNEL);
         if (!hpuxhdr)
                 goto out;
 
         retval = kernel_read(bprm->file, som_ex->aux_header_location,
                         (char *) hpuxhdr, size);
+        if (retval != size) {
+                if (retval >= 0)
+                        retval = -EIO;
+                goto out_free;
+        }
+
+        files = current->files; /* Refcounted so ok */
+        retval = unshare_files();
         if (retval < 0)
                 goto out_free;
-#error "Fix security hole before enabling me"
+        if (files == current->files) {
+                put_files_struct(files);
+                files = NULL;
+        }
+
         retval = get_unused_fd();
         if (retval < 0)
                 goto out_free;