Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.7 185/186] Documentation/module-signing.txt: Note need for version info if reusing a key | Date | Thu, 18 Aug 2016 16:00:02 +0200 |
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4.7-stable review patch. If anyone has any objections, please let me know.
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From: Ben Hutchings <ben@decadent.org.uk>
commit b8612e517c3c9809e1200b72c474dbfd969e5a83 upstream.
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> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- Documentation/module-signing.txt | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/Documentation/module-signing.txt +++ b/Documentation/module-signing.txt @@ -271,3 +271,9 @@ Since the private key is used to sign mo the private key to sign modules and compromise the operating system. The private key must be either destroyed or moved to a secure location and not kept in the root node of the kernel source tree. + +If you use the same private key to sign modules for multiple kernel +configurations, you must ensure that the module version information is +sufficient to prevent loading a module into a different kernel. Either +set CONFIG_MODVERSIONS=y or ensure that each configuration has a different +kernel release string by changing EXTRAVERSION or CONFIG_LOCALVERSION.
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