jbd2: checksum revocation blocks

[firefly-linux-kernel-4.4.55.git] / fs / jbd2 / recovery.c

diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index 980f3d6b5f884bed781185518415f4c95115a0d8..728ecd0705d9507ad43729e06f404301a639bac6 100644 (file)
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -706,6 +706,25 @@ static int do_one_pass(journal_t *journal,
        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 @@ static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
        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;