Implement support for protecting the exported symbols of
protected GKI modules.
Only signed GKI modules are permitted to export symbols
listed in the android/abi_gki_protected_exports file.
Attempting to export these symbols from an unsigned module
will result in the module failing to load, with a
'Permission denied' error message.
Bug: 232430739
Test: TH
Change-Id: I3e8b330938e116bb2e022d356ac0d55108a84a01
Signed-off-by: Ramji Jiyani <ramjiyani@google.com>
Add CONFIG_MODULE_SIG_PROTECT to enable lookup for the unprotected
symbols from the build time generated list of symbols.
Module loading behavior will change as follows:
- Allows Android GKI Modules signed using MODULE_SIG_ALL during build.
- Allows other modules to load if they don't violate the access to
Android GKI protected symbols. Loading will fail and return
-EACCES (Permission denied) if these modules access the symbol which
is not allowlisted via symbol list or exported by a GKI module.
Bug: 232430739
Test: TH
Signed-off-by: Ramji Jiyani <ramjiyani@google.com>
Change-Id: I751b1951241b45712c20ac0e3878abd2152dd002
This reverts commit f8bd6cf70d.
Reason for revert: Part of old protected/unprotected module implemenation.
It is being replaced by a new design listed as option 2A at
go/gki-modules-build-integration
Bug: 232430739
Test: TH
Signed-off-by: Ramji Jiyani <ramjiyani@google.com>
Change-Id: I0fbb4e4aede5f94c3454ea4be1735c837cae5118
Add CONFIG_MODULE_SIG_PROTECT to enable lookup for the protected
symbols and exports from the build time generated list of symbols
and exports.
Module loading behavior will change as follows:
- Allows Android GKI Modules signed using MODULE_SIG_ALL during build.
- Allows other modules to load if they don't violate the access to
Android GKI protected symbols and do not export the symbols already
exported by the Android GKI modules. Loading will fail and return
-EACCES (Permission denied) if symbol access contidions are not met.
Bug: 200082547
Test: Treehugger
Signed-off-by: Ramji Jiyani <ramjiyani@google.com>
Change-Id: Iedb99d8434db82a9c7f18ffd363d84f4b2316c5b
(cherry picked from commit 9ab6a242258a9ac17506b74c6ed7332703d536f4)
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public licence as published by
the free software foundation either version 2 of the licence or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 114 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a module is loaded, its symbols' Elf_Sym information is stored
in a symtab. Further, type information is also captured. Since
Elf_Sym has no type field, historically the st_info field has been
hijacked for storing type: st_info was overwritten.
commit 5439c985c5 ("module: Overwrite
st_size instead of st_info") changes that practice, as its one-liner
indicates. Unfortunately, this change overwrites symbol size,
information that a tool like DTrace expects to find.
Allocate a typetab array to store type information so that no Elf_Sym
field needs to be overwritten.
Fixes: 5439c985c5 ("module: Overwrite st_size instead of st_info")
Signed-off-by: Eugene Loh <eugene.loh@oracle.com>
Reviewed-by: Nick Alcock <nick.alcock@oracle.com>
[jeyu: renamed typeoff -> typeoffs ]
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Now that we have the load_info struct all initialized (including
info->name, which contains the name of the module) before
module_sig_check(), make the load_info struct and hence module name
available to mod_verify_sig() so that we can log the module name in the
event of an error.
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Separate the kernel signature checking keyring from module signing so that it
can be used by code other than the module-signing code.
Signed-off-by: David Howells <dhowells@redhat.com>
Emit the magic string that indicates a module has a signature after the
signature data instead of before it. This allows module_sig_check() to
be made simpler and faster by the elimination of the search for the
magic string. Instead we just need to do a single memcmp().
This works because at the end of the signature data there is the
fixed-length signature information block. This block then falls
immediately prior to the magic number.
From the contents of the information block, it is trivial to calculate
the size of the signature data and thus the size of the actual module
data.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Include a PGP keyring containing the public keys required to perform module
verification in the kernel image during build and create a special keyring
during boot which is then populated with keys of crypto type holding the public
keys found in the PGP keyring.
These can be seen by root:
[root@andromeda ~]# cat /proc/keys
07ad4ee0 I----- 1 perm 3f010000 0 0 crypto modsign.0: RSA 87b9b3bd []
15c7f8c3 I----- 1 perm 1f030000 0 0 keyring .module_sign: 1/4
...
It is probably worth permitting root to invalidate these keys, resulting in
their removal and preventing further modules from being loaded with that key.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We do a very simple search for a particular string appended to the module
(which is cache-hot and about to be SHA'd anyway). There's both a config
option and a boot parameter which control whether we accept or fail with
unsigned modules and modules that are signed with an unknown key.
If module signing is enabled, the kernel will be tainted if a module is
loaded that is unsigned or has a signature for which we don't have the
key.
(Useful feedback and tweaks by David Howells <dhowells@redhat.com>)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
