Verify the revoke block checksum when recovering the journal.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
e2fsck/recovery.c | 37 +++++++++++++++++++++++++++++++++++--
lib/ext2fs/kernel-jbd.h | 4 ++++
2 files changed, 39 insertions(+), 2 deletions(-)
diff --git a/e2fsck/recovery.c b/e2fsck/recovery.c
index b669941..8979193 100644
--- a/e2fsck/recovery.c
+++ b/e2fsck/recovery.c
@@ -674,8 +674,17 @@ static int do_one_pass(journal_t *journal,
err = scan_revoke_records(journal, bh,
next_commit_ID, info);
brelse(bh);
- if (err)
- goto failed;
+ if (err) {
+ if (err != -EINVAL)
+ goto failed;
+ /*
+ * Ignoring corrupt revoke blocks is safe
+ * because at worst it results in unnecessary
+ * writes during recovery.
+ */
+ jbd_debug(3, "Skipping corrupt revoke "
+ "block.\n");
+ }
continue;
default:
@@ -715,6 +724,27 @@ static int do_one_pass(journal_t *journal,
return err;
}
+static int jbd2_revoke_block_csum_verify(journal_t *j,
+ void *buf)
+{
+ struct journal_revoke_tail *tail;
+ __u32 provided, calculated;
+
+ if (!JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V2))
+ return 1;
+
+ tail = (struct journal_revoke_tail *)(buf + j->j_blocksize -
+ sizeof(struct journal_revoke_tail));
+ provided = tail->r_checksum;
+ tail->r_checksum = 0;
+ calculated = ext2fs_crc32c_le(~0, j->j_superblock->s_uuid,
+ sizeof(j->j_superblock->s_uuid));
+ calculated = ext2fs_crc32c_le(calculated, buf, j->j_blocksize);
+ tail->r_checksum = provided;
+
+ provided = ext2fs_be32_to_cpu(provided);
+ return provided == calculated;
+}
/* Scan a revoke record, marking all blocks mentioned as revoked. */
@@ -729,6 +759,9 @@ static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
offset = sizeof(journal_revoke_header_t);
max = be32_to_cpu(header->r_count);
+ if (!jbd2_revoke_block_csum_verify(journal, header))
+ return -EINVAL;
+
if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_64BIT))
record_len = 8;
diff --git a/lib/ext2fs/kernel-jbd.h b/lib/ext2fs/kernel-jbd.h
index 08479d3..187cb38 100644
--- a/lib/ext2fs/kernel-jbd.h
+++ b/lib/ext2fs/kernel-jbd.h
@@ -157,6 +157,10 @@ typedef struct journal_revoke_header_s
int r_count; /* Count of bytes used in the block */
} journal_revoke_header_t;
+/* Tail of revoke block, for checksumming */
+struct journal_revoke_tail {
+ __u32 r_checksum;
+};
/* Definitions for the journal tag flags word: */
#define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
--
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