tree d450dcf7832f0ec22f7371a9da7f3ab8be4ad875
parent c79bd89282136a4516e842fa542d6abf902ddeac
author Dan Rosenberg <drosenberg@vsecurity.com> 1285180376 -0400
committer Linus Torvalds <torvalds@linux-foundation.org> 1285201358 -0700

Prevent freeing uninitialized pointer in compat_do_readv_writev

In 32-bit compatibility mode, the error handling for
compat_do_readv_writev() may free an uninitialized pointer, potentially
leading to all sorts of ugly memory corruption.  This is reliably
triggerable by unprivileged users by invoking the readv()/writev()
syscalls with an invalid iovec pointer.  The below patch fixes this to
emulate the non-compat version.

Introduced by commit b83733639a49 ("compat: factor out
compat_rw_copy_check_uvector from compat_do_readv_writev")

Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
Cc: stable@kernel.org (2.6.35)
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>