From 42a7106de636ebf9c0b93d25b4230e14f5f2682e Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Sun, 27 May 2012 08:08:24 -0400 Subject: jbd2: checksum revocation blocks Compute and verify revoke blocks inside the journal. Signed-off-by: Darrick J. Wong Signed-off-by: "Theodore Ts'o" --- fs/jbd2/recovery.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'fs/jbd2/recovery.c') diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c index 980f3d6b5f88..728ecd0705d9 100644 --- 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; -- cgit v1.2.3-58-ga151