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authorMikulas Patocka <mpatocka@redhat.com>2021-01-21 18:09:32 +0300
committerMike Snitzer <snitzer@redhat.com>2021-02-03 18:10:05 +0300
commit09d85f8d8909ec8baa07479ba5777bbca24961f3 (patch)
tree6a66e25ef563aa53db9f148d08f2f531ddf36778 /Documentation/admin-guide/device-mapper
parent4c9e9883c20a3ad5384e689bdbb1d0677da4094c (diff)
downloadlinux-09d85f8d8909ec8baa07479ba5777bbca24961f3.tar.xz
dm integrity: introduce the "fix_hmac" argument
The "fix_hmac" argument improves security of internal_hash and journal_mac: - the section number is mixed to the mac, so that an attacker can't copy sectors from one journal section to another journal section - the superblock is protected by journal_mac - a 16-byte salt stored in the superblock is mixed to the mac, so that the attacker can't detect that two disks have the same hmac key and also to disallow the attacker to move sectors from one disk to another Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reported-by: Daniel Glockner <dg@emlix.com> Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> # ReST fix Tested-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'Documentation/admin-guide/device-mapper')
-rw-r--r--Documentation/admin-guide/device-mapper/dm-integrity.rst11
1 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/admin-guide/device-mapper/dm-integrity.rst b/Documentation/admin-guide/device-mapper/dm-integrity.rst
index 2cc5488acbd9..ef762857da95 100644
--- a/Documentation/admin-guide/device-mapper/dm-integrity.rst
+++ b/Documentation/admin-guide/device-mapper/dm-integrity.rst
@@ -186,6 +186,17 @@ fix_padding
space-efficient. If this option is not present, large padding is
used - that is for compatibility with older kernels.
+fix_hmac
+ Improve security of internal_hash and journal_mac:
+
+ - the section number is mixed to the mac, so that an attacker can't
+ copy sectors from one journal section to another journal section
+ - the superblock is protected by journal_mac
+ - a 16-byte salt stored in the superblock is mixed to the mac, so
+ that the attacker can't detect that two disks have the same hmac
+ key and also to disallow the attacker to move sectors from one
+ disk to another
+
legacy_recalculate
Allow recalculating of volumes with HMAC keys. This is disabled by
default for security reasons - an attacker could modify the volume,