mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-13 23:29:10 -04:00
b358f23ab1
Commita2471684da("crypto: ecdsa - Move X9.62 signature size calculation into template") introduced ->max_size() and ->digest_size() callbacks to struct sig_alg. They return an algorithm's maximum signature size and digest size, respectively. For algorithms which lack these callbacks, crypto_register_sig() was amended to use the ->key_size() callback instead. However the commit neglected to also amend sig_register_instance(). As a result, the ->max_size() and ->digest_size() callbacks remain NULL pointers if instances do not define them. A KEYCTL_PKEY_QUERY system call results in an oops for such instances: BUG: kernel NULL pointer dereference, address: 0000000000000000 Call Trace: software_key_query+0x169/0x370 query_asymmetric_key+0x67/0x90 keyctl_pkey_query+0x86/0x120 __do_sys_keyctl+0x428/0x480 do_syscall_64+0x4b/0x110 The only instances affected by this are "pkcs1(rsa, ...)". Fix by moving the callback checks from crypto_register_sig() to sig_prepare_alg(), which is also invoked by sig_register_instance(). Change the return type of sig_prepare_alg() from void to int to be able to return errors. This matches other algorithm types, see e.g. aead_prepare_alg() or ahash_prepare_alg(). Fixes:a2471684da("crypto: ecdsa - Move X9.62 signature size calculation into template") Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
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.