[PATCH] spufs: check for proper file pointer in sys_spu_run
Only checking for SPUFS_MAGIC is not reliable, because
it might not be unique in theory. Worse than that,
we accidentally allow spu_run to be performed on
any file in spufs, not just those returned from
spu_create as intended.
Noticed by Al Viro.
Signed-off-by: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c
index 4594401..e314f18 100644
--- a/arch/powerpc/platforms/cell/spufs/inode.c
+++ b/arch/powerpc/platforms/cell/spufs/inode.c
@@ -212,7 +212,7 @@
.lookup = simple_lookup,
};
-struct file_operations spufs_autodelete_dir_operations = {
+struct file_operations spufs_context_fops = {
.open = dcache_dir_open,
.release = spufs_dir_close,
.llseek = dcache_dir_lseek,
@@ -301,7 +301,7 @@
put_unused_fd(ret);
ret = PTR_ERR(filp);
} else {
- filp->f_op = &spufs_autodelete_dir_operations;
+ filp->f_op = &spufs_context_fops;
fd_install(ret, filp);
}
diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h
index 17cae5e..420953b 100644
--- a/arch/powerpc/platforms/cell/spufs/spufs.h
+++ b/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -103,6 +103,7 @@
struct spu_context *ctx, u32 *npc, u32 *status);
long spufs_create_thread(struct nameidata *nd, const char *name,
unsigned int flags, mode_t mode);
+extern struct file_operations spufs_context_fops;
/* context management */
struct spu_context * alloc_spu_context(struct address_space *local_store);
diff --git a/arch/powerpc/platforms/cell/spufs/syscalls.c b/arch/powerpc/platforms/cell/spufs/syscalls.c
index 17a2b51..0c2896a 100644
--- a/arch/powerpc/platforms/cell/spufs/syscalls.c
+++ b/arch/powerpc/platforms/cell/spufs/syscalls.c
@@ -39,8 +39,9 @@
if (get_user(npc, unpc) || get_user(status, ustatus))
goto out;
+ /* check if this file was created by spu_create */
ret = -EINVAL;
- if (filp->f_vfsmnt->mnt_sb->s_magic != SPUFS_MAGIC)
+ if (filp->f_op != &spufs_context_fops)
goto out;
i = SPUFS_I(filp->f_dentry->d_inode);