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https://github.com/torvalds/linux
23 October 2021, 00:29:24 UTC
Revision 72f9a07b6bfaefdc29fcb75dafa8867a4f6d8317 authored by Eric Biggers on 08 December 2017, 15:13:29 UTC, committed by David Howells on 08 December 2017, 15:13:29 UTC 
KEYS: be careful with error codes in public_key_verify_signature()
 
In public_key_verify_signature(), if akcipher_request_alloc() fails, we
return -ENOMEM.  But that error code was set 25 lines above, and by
accident someone could easily insert new code in between that assigns to
'ret', which would introduce a signature verification bypass.  Make the
code clearer by moving the -ENOMEM down to where it is used.

Additionally, the callers of public_key_verify_signature() only consider
a negative return value to be an error.  This means that if any positive
return value is accidentally introduced deeper in the call stack (e.g.
'return EBADMSG' instead of 'return -EBADMSG' somewhere in RSA),
signature verification will be bypassed.  Make things more robust by
having public_key_verify_signature() warn about positive errors and
translate them into -EINVAL.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
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Tip revision: 72f9a07b6bfaefdc29fcb75dafa8867a4f6d8317 authored by Eric Biggers on 08 December 2017, 15:13:29 UTC
KEYS: be careful with error codes in public_key_verify_signature()
Tip revision: 72f9a07
README 
Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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