gen_init_cpio: fix short read file handling

When processing a "file" entry, gen_init_cpio attempts to allocate a
buffer large enough to stage the entire contents of the source file.  It
then attempts to fill the buffer via a single read() call and subsequently
writes out the entire buffer length, without checking that read() returned
the full length, potentially writing uninitialized buffer memory.

Fix this by breaking up file I/O into 64k chunks and only writing the
length returned by the prior read() call.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Disseldorp <[email protected]>
Reviewed-by: Martin Wilck <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions