summaryrefslogtreecommitdiff
path: root/Documentation
diff options
context:
space:
mode:
authorBen Hutchings <ben@decadent.org.uk>2016-04-28 09:24:05 +0930
committerSasha Levin <alexander.levin@verizon.com>2016-08-22 12:23:18 -0400
commit5a7dd70c6bd89f9b17065893aa931a5fc8dbe32c (patch)
treeabf182054b5bdda93a5269b904a628bca5b1fc42 /Documentation
parent1d307756e9b9b25c1cc0f54cb061794393b0aea6 (diff)
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>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/module-signing.txt6
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/module-signing.txt b/Documentation/module-signing.txt
index 09c2382ad055..e3af8c27eef2 100644
--- a/Documentation/module-signing.txt
+++ b/Documentation/module-signing.txt
@@ -239,3 +239,9 @@ 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.