jbd2: checksum revocation blocks
Compute and verify revoke blocks inside the journal.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index 980f3d6..728ecd0 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -706,6 +706,25 @@
return err;
}
+static int jbd2_revoke_block_csum_verify(journal_t *j,
+ void *buf)
+{
+ struct jbd2_journal_revoke_tail *tail;
+ __u32 provided, calculated;
+
+ if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ return 1;
+
+ tail = (struct jbd2_journal_revoke_tail *)(buf + j->j_blocksize -
+ sizeof(struct jbd2_journal_revoke_tail));
+ provided = tail->r_checksum;
+ tail->r_checksum = 0;
+ calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
+ tail->r_checksum = provided;
+
+ provided = be32_to_cpu(provided);
+ return provided == calculated;
+}
/* Scan a revoke record, marking all blocks mentioned as revoked. */
@@ -720,6 +739,9 @@
offset = sizeof(jbd2_journal_revoke_header_t);
max = be32_to_cpu(header->r_count);
+ if (!jbd2_revoke_block_csum_verify(journal, header))
+ return -EINVAL;
+
if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
record_len = 8;