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2016-07-27Documentation/module-signing.txt: Note need for version info if reusing a keyBen Hutchings
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>
2016-03-12modsign: Fix documentation on module signing enforcement parameter.James Johnston
Modify the documentation to match the actual parameter as implemented in kernel/module.c:273. Signed-off-by: James Johnston <johnstonj.public@codenest.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-08-14Move certificate handling to its own directoryDavid Howells
Move certificate handling out of the kernel/ directory and into a certs/ directory to get all the weird stuff in one place and move the generated signing keys into this directory. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
2015-08-12sign-file: Document dependency on OpenSSL devel librariesDavid Howells
The revised sign-file program is no longer a script that wraps the openssl program, but now rather a program that makes use of OpenSSL's crypto library. This means that to build the sign-file program, the kernel build process now has a dependency on the OpenSSL development packages in addition to OpenSSL itself. Document this in Kconfig and in module-signing.txt. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
2015-08-07modsign: Add explicit CONFIG_SYSTEM_TRUSTED_KEYS optionDavid Woodhouse
Let the user explicitly provide a file containing trusted keys, instead of just automatically finding files matching *.x509 in the build tree and trusting whatever we find. This really ought to be an *explicit* configuration, and the build rules for dealing with the files were fairly painful too. Fix applied from James Morris that removes an '=' from a macro definition in kernel/Makefile as this is a feature that only exists from GNU make 3.82 onwards. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David Howells <dhowells@redhat.com>
2015-08-07modsign: Use single PEM file for autogenerated keyDavid Woodhouse
The current rule for generating signing_key.priv and signing_key.x509 is a classic example of a bad rule which has a tendency to break parallel make. When invoked to create *either* target, it generates the other target as a side-effect that make didn't predict. So let's switch to using a single file signing_key.pem which contains both key and certificate. That matches what we do in the case of an external key specified by CONFIG_MODULE_SIG_KEY anyway, so it's also slightly cleaner. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David Howells <dhowells@redhat.com>
2015-08-07modsign: Extract signing cert from CONFIG_MODULE_SIG_KEY if neededDavid Woodhouse
Where an external PEM file or PKCS#11 URI is given, we can get the cert from it for ourselves instead of making the user drop signing_key.x509 in place for us. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David Howells <dhowells@redhat.com>
2015-08-07modsign: Allow external signing key to be specifiedDavid Woodhouse
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David Howells <dhowells@redhat.com>
2015-08-07modsign: Allow password to be specified for signing keyDavid Woodhouse
We don't want this in the Kconfig since it might then get exposed in /proc/config.gz. So make it a parameter to Kbuild instead. This also means we don't have to jump through hoops to strip quotes from it, as we would if it was a config option. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-04-30modsign: change default key detailsDavid Howells
Change default key details to be more obviously unspecified. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-06Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "Nothing major: the stricter permissions checking for sysfs broke a staging driver; fix included. Greg KH said he'd take the patch but hadn't as the merge window opened, so it's included here to avoid breaking build" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: staging: fix up speakup kobject mode Use 'E' instead of 'X' for unsigned module taint flag. VERIFY_OCTAL_PERMISSIONS: stricter checking for sysfs perms. kallsyms: fix percpu vars on x86-64 with relocation. kallsyms: generalize address range checking module: LLVMLinux: Remove unused function warning from __param_check macro Fix: module signature vs tracepoints: add new TAINT_UNSIGNED_MODULE module: remove MODULE_GENERIC_TABLE module: allow multiple calls to MODULE_DEVICE_TABLE() per module module: use pr_cont
2014-03-31Use 'E' instead of 'X' for unsigned module taint flag.Rusty Russell
Takashi Iwai <tiwai@suse.de> says: > The letter 'X' has been already used for SUSE kernels for very long > time, to indicate the external supported modules. Can the new flag be > changed to another letter for avoiding conflict...? > (BTW, we also use 'N' for "no support", too.) Note: this code should be cleaned up, so we don't have such maps in three places! Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-03-13Fix: module signature vs tracepoints: add new TAINT_UNSIGNED_MODULEMathieu Desnoyers
Users have reported being unable to trace non-signed modules loaded within a kernel supporting module signature. This is caused by tracepoint.c:tracepoint_module_coming() refusing to take into account tracepoints sitting within force-loaded modules (TAINT_FORCED_MODULE). The reason for this check, in the first place, is that a force-loaded module may have a struct module incompatible with the layout expected by the kernel, and can thus cause a kernel crash upon forced load of that module on a kernel with CONFIG_TRACEPOINTS=y. Tracepoints, however, specifically accept TAINT_OOT_MODULE and TAINT_CRAP, since those modules do not lead to the "very likely system crash" issue cited above for force-loaded modules. With kernels having CONFIG_MODULE_SIG=y (signed modules), a non-signed module is tainted re-using the TAINT_FORCED_MODULE taint flag. Unfortunately, this means that Tracepoints treat that module as a force-loaded module, and thus silently refuse to consider any tracepoint within this module. Since an unsigned module does not fit within the "very likely system crash" category of tainting, add a new TAINT_UNSIGNED_MODULE taint flag to specifically address this taint behavior, and accept those modules within Tracepoints. We use the letter 'X' as a taint flag character for a module being loaded that doesn't know how to sign its name (proposed by Steven Rostedt). Also add the missing 'O' entry to trace event show_module_flags() list for the sake of completeness. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> NAKed-by: Ingo Molnar <mingo@redhat.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: David Howells <dhowells@redhat.com> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-02-20doc: Insert MODULE_ in module-signing macrosPaul Bolle
Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-12-13Add Documentation/module-signing.txt fileJames Solner
This patch adds the Documentation/module-signing.txt file that is currently missing from the Documentation directory. The init/Kconfig file references the Documentation/module-signing.txt file to explain how kernel module signing works. This patch supplies this documentation. Signed-off-by: James Solner <solner@alcatel-lucent.com> Signed-off-by: David Howells <dhowells@redhat.com>