dm-integrity signals integrity violations by returning I/O errors to user space. To identify integrity violations by a controlling instance, the kernel audit subsystem can be used to emit audit events to user space. We use the new dm-audit submodule allowing to emit audit events on relevant I/O errors.
The construction and destruction of integrity device mappings are also relevant for auditing a system. Thus, those events are also logged as audit events. Signed-off-by: Michael Weiß <michael.we...@aisec.fraunhofer.de> --- drivers/md/dm-integrity.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index 20f2510db1f6..a881ead4b506 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -23,6 +23,8 @@ #include <linux/async_tx.h> #include <linux/dm-bufio.h> +#include "dm-audit.h" + #define DM_MSG_PREFIX "integrity" #define DEFAULT_INTERLEAVE_SECTORS 32768 @@ -539,6 +541,7 @@ static int sb_mac(struct dm_integrity_c *ic, bool wr) } if (memcmp((__u8 *)ic->sb + (1 << SECTOR_SHIFT) - size, result, size)) { dm_integrity_io_error(ic, "superblock mac", -EILSEQ); + dm_audit_log_target(DM_MSG_PREFIX, "mac-superblock", ic->ti, 0); return -EILSEQ; } } @@ -876,8 +879,10 @@ static void rw_section_mac(struct dm_integrity_c *ic, unsigned section, bool wr) if (likely(wr)) memcpy(&js->mac, result + (j * JOURNAL_MAC_PER_SECTOR), JOURNAL_MAC_PER_SECTOR); else { - if (memcmp(&js->mac, result + (j * JOURNAL_MAC_PER_SECTOR), JOURNAL_MAC_PER_SECTOR)) + if (memcmp(&js->mac, result + (j * JOURNAL_MAC_PER_SECTOR), JOURNAL_MAC_PER_SECTOR)) { dm_integrity_io_error(ic, "journal mac", -EILSEQ); + dm_audit_log_target(DM_MSG_PREFIX, "mac-journal", ic->ti, 0); + } } } } @@ -1782,10 +1787,15 @@ static void integrity_metadata(struct work_struct *w) if (unlikely(r)) { if (r > 0) { char b[BDEVNAME_SIZE]; - DMERR_LIMIT("%s: Checksum failed at sector 0x%llx", bio_devname(bio, b), - (sector - ((r + ic->tag_size - 1) / ic->tag_size))); + sector_t s; + + s = sector - ((r + ic->tag_size - 1) / ic->tag_size); + DMERR_LIMIT("%s: Checksum failed at sector 0x%llx", + bio_devname(bio, b), s); r = -EILSEQ; atomic64_inc(&ic->number_of_mismatches); + dm_audit_log_bio(DM_MSG_PREFIX, "integrity-checksum", + bio, s, 0); } if (likely(checksums != checksums_onstack)) kfree(checksums); @@ -1991,6 +2001,8 @@ static bool __journal_read_write(struct dm_integrity_io *dio, struct bio *bio, if (unlikely(memcmp(checksums_onstack, journal_entry_tag(ic, je), ic->tag_size))) { DMERR_LIMIT("Checksum failed when reading from journal, at sector 0x%llx", logical_sector); + dm_audit_log_bio(DM_MSG_PREFIX, "journal-checksum", + bio, logical_sector, 0); } } #endif @@ -2534,8 +2546,10 @@ static void do_journal_write(struct dm_integrity_c *ic, unsigned write_start, integrity_sector_checksum(ic, sec + ((l - j) << ic->sb->log2_sectors_per_block), (char *)access_journal_data(ic, i, l), test_tag); - if (unlikely(memcmp(test_tag, journal_entry_tag(ic, je2), ic->tag_size))) + if (unlikely(memcmp(test_tag, journal_entry_tag(ic, je2), ic->tag_size))) { dm_integrity_io_error(ic, "tag mismatch when replaying journal", -EILSEQ); + dm_audit_log_target(DM_MSG_PREFIX, "integrity-replay-journal", ic->ti, 0); + } } journal_entry_set_unused(je2); @@ -4490,9 +4504,11 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv) if (ic->discard) ti->num_discard_bios = 1; + dm_audit_log_ctr(DM_MSG_PREFIX, ti, 1); return 0; bad: + dm_audit_log_ctr(DM_MSG_PREFIX, ti, 0); dm_integrity_dtr(ti); return r; } @@ -4566,6 +4582,7 @@ static void dm_integrity_dtr(struct dm_target *ti) free_alg(&ic->journal_mac_alg); kfree(ic); + dm_audit_log_dtr(DM_MSG_PREFIX, ti, 1); } static struct target_type integrity_target = { -- 2.20.1 -- Linux-audit mailing list Linux-audit@redhat.com https://listman.redhat.com/mailman/listinfo/linux-audit