[PATCH 03/26] xfs: validate ondisk/incore dquot flags

Darrick J. Wong
2020-07-15T01:50:59Z

While loading dquot records off disk, make sure that the quota type
flags are the same between the incore dquot and the ondisk dquot.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/xfs_dquot.c | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index 76353c9a723e..7503c6695569 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -23,6 +23,7 @@
#include "xfs_trace.h"
#include "xfs_log.h"
#include "xfs_bmap_btree.h"
+#include "xfs_error.h"

/*
* Lock order:
@@ -524,13 +525,26 @@ xfs_dquot_alloc(
}

/* Copy the in-core quota fields in from the on-disk buffer. */
-STATIC void
+STATIC int
xfs_dquot_from_disk(
struct xfs_dquot *dqp,
struct xfs_buf *bp)
{
struct xfs_disk_dquot *ddqp = bp->b_addr + dqp->q_bufoffset;

+ /*
+ * Ensure that we got the type and ID we were looking for.
+ * Everything else was checked by the dquot buffer verifier.
+ */
+ if ((ddqp->d_flags & XFS_DQ_ALLTYPES) != dqp->dq_flags ||
+ ddqp->d_id != dqp->q_core.d_id) {
+ xfs_alert_tag(bp->b_mount, XFS_PTAG_VERIFIER_ERROR,
+ "Metadata corruption detected at %pS, quota %u",
+ __this_address, be32_to_cpu(dqp->q_core.d_id));
+ xfs_alert(bp->b_mount, "Unmount and run xfs_repair");
+ return -EFSCORRUPTED;
+ }
+
/* copy everything from disk dquot to the incore dquot */
memcpy(&dqp->q_core, ddqp, sizeof(struct xfs_disk_dquot));

@@ -544,6 +558,7 @@ xfs_dquot_from_disk(

/* initialize the dquot speculative prealloc thresholds */
xfs_dquot_set_prealloc_limits(dqp);
+ return 0;
}

/* Allocate and initialize the dquot buffer for this in-core dquot. */
@@ -617,9 +632,11 @@ xfs_qm_dqread(
* further.
*/
ASSERT(xfs_buf_islocked(bp));
- xfs_dquot_from_disk(dqp, bp);
-
+ error = xfs_dquot_from_disk(dqp, bp);
xfs_buf_relse(bp);
+ if (error)
+ goto err;
+
*dqpp = dqp;
return error;