Documentation/module-signing.txt: Note need for version info if reusing a key

Documentation/module-signing.txt: Note need for version info if reusing a key

[ Upstream commit b8612e517c3c9809e1200b72c474dbfd969e5a83 ]

Signing a module should only make it trusted by the specific kernel it
was built for, not anything else.  If a module signing key is used for
multiple ABI-incompatible kernels, the modules need to include enough
version information to distinguish them.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>