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authorArnd Bergmann <arnd.bergmann@de.ibm.com>2007-03-10 00:05:35 +0100
committerArnd Bergmann <arnd@klappe.arndb.de>2007-03-10 00:07:48 +0100
commitaa0ed2bdb663608d5e409faecff3e1e81a3d413a (patch)
tree88382df6dec804ae319316753c661c8212cd0832 /arch/powerpc/platforms/cell/spufs
parentf194bda4ce7e71cc95535f494a4a5515cd91ed85 (diff)
[POWERPC] spufs: fix possible memory corruption is spufs_mem_write
Due to a buggy unsigned comparison, it was possible to write beyond the end of the local store file in spufs under some circumstances. This rewrites the buggy function to look more like simple_copy_from_buffer. Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com> Cc: Ulrich Weigand <Ulrich.Weigand@de.ibm.com>
Diffstat (limited to 'arch/powerpc/platforms/cell/spufs')
-rw-r--r--arch/powerpc/platforms/cell/spufs/file.c24
1 files changed, 14 insertions, 10 deletions
diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index b00653d69c0..505266a568d 100644
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/arch/powerpc/platforms/cell/spufs/file.c
@@ -63,8 +63,8 @@ static ssize_t
spufs_mem_read(struct file *file, char __user *buffer,
size_t size, loff_t *pos)
{
- int ret;
struct spu_context *ctx = file->private_data;
+ ssize_t ret;
spu_acquire(ctx);
ret = __spufs_mem_read(ctx, buffer, size, pos);
@@ -74,25 +74,29 @@ spufs_mem_read(struct file *file, char __user *buffer,
static ssize_t
spufs_mem_write(struct file *file, const char __user *buffer,
- size_t size, loff_t *pos)
+ size_t size, loff_t *ppos)
{
struct spu_context *ctx = file->private_data;
char *local_store;
+ loff_t pos = *ppos;
int ret;
- size = min_t(ssize_t, LS_SIZE - *pos, size);
- if (size <= 0)
+ if (pos < 0)
+ return -EINVAL;
+ if (pos > LS_SIZE)
return -EFBIG;
- *pos += size;
+ if (size > LS_SIZE - pos)
+ size = LS_SIZE - pos;
spu_acquire(ctx);
-
local_store = ctx->ops->get_ls(ctx);
- ret = copy_from_user(local_store + *pos - size,
- buffer, size) ? -EFAULT : size;
-
+ ret = copy_from_user(local_store + pos, buffer, size);
spu_release(ctx);
- return ret;
+
+ if (ret)
+ return -EFAULT;
+ *ppos = pos + size;
+ return size;
}
static unsigned long spufs_mem_mmap_nopfn(struct vm_area_struct *vma,