On first corruption the verity targets triggers a "dm_target_update" event. This allows other systems to detect the corruption via IMA instead of manually querying the table. The corruption cannot be detected using the other IMA measurements because "dm_table_load" only measures the table content during target creation. Using the new "dm_target_update" remeasures the target table entries during runtime.
The event is only triggered if the target was not corrupted before because verity_handle_err(..) is still called when the target is corrupted and the IMA log should only contain an entry when the table changed. Signed-off-by: Thore Sommer <[email protected]> --- - v1: rewrite check to not use an extra variable drivers/md/dm-verity-target.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c index 80133aae0db3..5133c2274057 100644 --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -16,6 +16,7 @@ #include "dm-verity.h" #include "dm-verity-fec.h" #include "dm-verity-verify-sig.h" +#include "dm-ima.h" #include <linux/module.h> #include <linux/reboot.h> #include <linux/scatterlist.h> @@ -219,8 +220,13 @@ static int verity_handle_err(struct dm_verity *v, enum verity_block_type type, const char *type_str = ""; struct mapped_device *md = dm_table_get_md(v->ti->table); - /* Corruption should be visible in device status in all modes */ - v->hash_failed = 1; + /* Only change and measure change if not already corrupted */ + if (!v->hash_failed) { + /* Corruption should be visible in device status in all modes */ + v->hash_failed = 1; + /* After the state has changed remeasure target table */ + dm_ima_measure_on_target_update(v->ti); + } if (v->corrupted_errs >= DM_VERITY_MAX_CORRUPTED_ERRS) goto out; -- 2.36.0 -- dm-devel mailing list [email protected] https://listman.redhat.com/mailman/listinfo/dm-devel
