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| author | Ben Hutchings <ben@decadent.org.uk> | 2016-04-28 09:24:05 +0930 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-20 18:11:04 +0200 |
| commit | 799c8305a1ee822647df272d77f61ae28acd31ab (patch) | |
| tree | 0fc488a319cb31cb59f88081a0ff0055d3e1179f | |
| parent | c528032b3adf734fba3247517641ee173b26d950 (diff) | |
| download | lwn-799c8305a1ee822647df272d77f61ae28acd31ab.tar.gz lwn-799c8305a1ee822647df272d77f61ae28acd31ab.zip | |
Documentation/module-signing.txt: Note need for version info if reusing a key
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>
| -rw-r--r-- | Documentation/module-signing.txt | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/module-signing.txt b/Documentation/module-signing.txt index 696d5caf4fd8..f0e3361db20c 100644 --- a/Documentation/module-signing.txt +++ b/Documentation/module-signing.txt @@ -271,3 +271,9 @@ Since the private key is used to sign modules, viruses and malware could use 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. |