FAILED: patch "[PATCH] xfs: improve dirent bounds checking in scrub and repair" failed to apply to 6.18-stable tree

FAILED: patch "[PATCH] xfs: improve dirent bounds checking in scrub and repair" failed to apply to 6.18-stable tree

[gregkh]

The patch below does not apply to the 6.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 5d470234d04dae6fe2ca2cf4b9ef277b78c7e05a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026110438-luckless-handiwork-a5c4@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5d470234d04dae6fe2ca2cf4b9ef277b78c7e05a Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <djwong@kernel.org>
Date: Mon, 12 Oct 2026 23:10:09 -0700
Subject: [PATCH] xfs: improve dirent bounds checking in scrub and repair

LOLLM complains that we don't do enough bounds checking of the directory
entries in directory blocks when we're looking for errors or trying to
salvage entries.  Let's improve that with more detailed checks.

Cc: stable@vger.kernel.org # v4.16
Fixes: ce92d29ddf9908 ("xfs: directory scrubber must walk through data block to offset")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Assisted-by: LOLLM # finding obvious bugs
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
index 8de593c5382d..d99e2a732723 100644
--- a/fs/xfs/scrub/dir.c
+++ b/fs/xfs/scrub/dir.c
@@ -325,11 +325,24 @@ xchk_dir_check_unused(
 	struct xchk_da_btree		*ds,
 	struct xfs_buf			*bp,
 	unsigned int			iter_off,
-	unsigned int			end)
+	unsigned int			end,
+	xfs_dablk_t			rec_bno)
 {
 	struct xfs_dir2_data_unused	*dup = bp->b_addr + iter_off;
+	unsigned int			advance;
 
-	return be16_to_cpu(dup->length);
+	if (iter_off + sizeof(*dup) > end) {
+		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		return -1;
+	}
+
+	advance = xfs_dir2_data_unusedsize(be16_to_cpu(dup->length));
+	if (!advance || iter_off + advance > end) {
+		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		return -1;
+	}
+
+	return advance;
 }
 
 /*
@@ -343,15 +356,31 @@ xchk_dir_check_entry(
 	struct xfs_buf			*bp,
 	unsigned int			iter_off,
 	unsigned int			end,
-	struct xfs_dir2_data_entry	*dent)
+	struct xfs_dir2_data_entry	*dent,
+	xfs_dablk_t			rec_bno)
 {
 	struct xfs_dir2_data_entry	*dep = bp->b_addr + iter_off;
 	struct xfs_mount		*mp = ds->state->mp;
+	unsigned int			advance;
+
+	/* must have namelen */
+	advance = offsetof(typeof(*dep), name);
+	if (iter_off + advance >= end) {
+		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		return -1;
+	}
+
+	/* Don't walk off the end of the block. */
+	advance = xfs_dir2_data_entsize(mp, dep->namelen);
+	if (!advance || iter_off + advance > end) {
+		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		return -1;
+	}
 
 	if (dep == dent)
 		return 0;
 
-	return xfs_dir2_data_entsize(mp, dep->namelen);
+	return advance;
 }
 
 /* Scrub a directory btree record. */
@@ -379,6 +408,7 @@ xchk_dir_rec(
 	xfs_dahash_t			hash;
 	struct xfs_dir3_icleaf_hdr	hdr;
 	unsigned int			tag;
+	bool				foundit = false;
 	int				error;
 
 	ASSERT(blk->magic == XFS_DIR2_LEAF1_MAGIC ||
@@ -423,33 +453,44 @@ xchk_dir_rec(
 	dent = bp->b_addr + off;
 
 	/* Make sure we got a real directory entry. */
-	iter_off = geo->data_entry_offset;
 	end = xfs_dir3_data_end_offset(geo, bp->b_addr);
 	if (!end) {
 		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
 		goto out_relse;
 	}
-	for (;;) {
+	iter_off = geo->data_entry_offset;
+	while (iter_off < end) {
 		struct xfs_dir2_data_unused	*dup = bp->b_addr + iter_off;
 		int				advance;
 
-		if (iter_off >= end) {
+		/* must have freetag */
+		advance = offsetof(typeof(*dup), length);
+		if (iter_off + advance >= end) {
 			xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
 			goto out_relse;
 		}
 
 		if (dup->freetag == cpu_to_be16(XFS_DIR2_DATA_FREE_TAG))
-			advance = xchk_dir_check_unused(ds, bp, iter_off, end);
+			advance = xchk_dir_check_unused(ds, bp, iter_off, end,
+					rec_bno);
 		else
 			advance = xchk_dir_check_entry(ds, bp, iter_off, end,
-					dent);
+					dent, rec_bno);
 		if (advance < 0)
 			goto out_relse;
-		if (!advance)
+		if (!advance) {
+			foundit = true;
 			break;
+		}
 		iter_off += advance;
 	}
 
+	/* Hash tree must point to the exact dirent */
+	if (!foundit) {
+		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		goto out_relse;
+	}
+
 	/* Retrieve the entry, sanity check it, and compare hashes. */
 	ino = be64_to_cpu(dent->inumber);
 	hash = be32_to_cpu(ent->hashval);
@@ -461,6 +502,13 @@ xchk_dir_rec(
 		goto out_relse;
 	}
 
+	/* Name must not overflow end of block */
+	if ((char *)dent->name + dent->namelen >
+	    (char *)bp->b_addr + BBTOB(bp->b_length)) {
+		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		goto out_relse;
+	}
+
 	/* Does the directory hash match? */
 	dname.name = dent->name;
 	dname.len = dent->namelen;
diff --git a/fs/xfs/scrub/dir_repair.c b/fs/xfs/scrub/dir_repair.c
index ea4e729ec036..518e15d93d3b 100644
--- a/fs/xfs/scrub/dir_repair.c
+++ b/fs/xfs/scrub/dir_repair.c
@@ -473,8 +473,16 @@ xrep_dir_recover_unused(
 	unsigned int			end)
 {
 	struct xfs_dir2_data_unused	*dup = bp->b_addr + offset;
+	unsigned int			advance;
 
-	return be16_to_cpu(dup->length);
+	if (offset + sizeof(*dup) > end)
+		return 0;
+
+	advance = xfs_dir2_data_unusedsize(be16_to_cpu(dup->length));
+	if (!advance || offset + advance > end)
+		return 0;
+
+	return advance;
 }
 
 /*
@@ -492,11 +500,14 @@ xrep_dir_recover_entry(
 	unsigned int			advance;
 	int				error;
 
+	/* must have namelen */
+	advance = offsetof(typeof(*dep), name);
+	if (offset + advance >= end)
+		return 0;
+
 	/* Don't walk off the end of the block. */
 	advance = xfs_dir2_data_entsize(rd->sc->mp, dep->namelen);
-	if (!advance)
-		return 0;
-	if (offset + advance > end)
+	if (!advance || offset + advance > end)
 		return 0;
 
 	/* Ok, let's save this entry. */
@@ -534,6 +545,11 @@ xrep_dir_recover_data(
 		if (xchk_should_terminate(rd->sc, &error))
 			return error;
 
+		/* must have freetag */
+		advance = offsetof(typeof(*dup), length);
+		if (offset + advance >= end)
+			break;
+
 		if (dup->freetag == cpu_to_be16(XFS_DIR2_DATA_FREE_TAG))
 			advance = xrep_dir_recover_unused(bp, offset, end);
 		else
@@ -565,6 +581,19 @@ xrep_dir_recover_sf(
 	hdr = ifp->if_data;
 	end = (unsigned char *)ifp->if_data + ifp->if_bytes;
 
+	/* sf header must be big enough for count/i8count */
+	if (!hdr || ifp->if_bytes < 2)
+		return 0;
+
+	/* and large enough for the parent inumber */
+	if (hdr->i8count) {
+		if (ifp->if_bytes < offsetof(struct xfs_dir2_sf_hdr, parent[8]))
+			return 0;
+	} else {
+		if (ifp->if_bytes < offsetof(struct xfs_dir2_sf_hdr, parent[4]))
+			return 0;
+	}
+
 	ino = xfs_dir2_sf_get_parent_ino(hdr);
 	trace_xrep_dir_salvaged_parent(rd->sc->ip, ino);
 

[PATCH 6.18.y 1/2] xfs: refactor directory data block walking loops in scrub

[Sasha Levin]

From: "Darrick J. Wong" <djwong@kernel.org>

[ Upstream commit 19b5653cc870788df71e7fcf2dd7b6131d8868dc ]

Hoist the inner loop code of the directory data block walking code in
the directory scrub and repair code to separate functions in preparation
for strengthening the validation in a subsequent patch.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Stable-dep-of: 5d470234d04d ("xfs: improve dirent bounds checking in scrub and repair")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/xfs/scrub/dir.c        | 56 ++++++++++++++++++++++++++----
 fs/xfs/scrub/dir_repair.c | 73 ++++++++++++++++++++++++++++-----------
 2 files changed, 102 insertions(+), 27 deletions(-)

diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
index 7b0a9d2aea3ec..2f73baee0f0b4 100644
--- a/fs/xfs/scrub/dir.c
+++ b/fs/xfs/scrub/dir.c
@@ -313,6 +313,45 @@ xchk_dir_actor(
 	return error;
 }
 
+/*
+ * Deal with an unused directory entry.  Returns a positive number of bytes to
+ * advance in the directory block, zero to stop processing, or -1 if corruption
+ * was found.
+ */
+static int
+xchk_dir_check_unused(
+	struct xchk_da_btree		*ds,
+	struct xfs_buf			*bp,
+	unsigned int			iter_off,
+	unsigned int			end)
+{
+	struct xfs_dir2_data_unused	*dup = bp->b_addr + iter_off;
+
+	return be16_to_cpu(dup->length);
+}
+
+/*
+ * Check a directory entry.  Returns a positive number of bytes to advance
+ * in the directory block, zero to stop processing, or -1 if corruption was
+ * found.
+ */
+static int
+xchk_dir_check_entry(
+	struct xchk_da_btree		*ds,
+	struct xfs_buf			*bp,
+	unsigned int			iter_off,
+	unsigned int			end,
+	struct xfs_dir2_data_entry	*dent)
+{
+	struct xfs_dir2_data_entry	*dep = bp->b_addr + iter_off;
+	struct xfs_mount		*mp = ds->state->mp;
+
+	if (dep == dent)
+		return 0;
+
+	return xfs_dir2_data_entsize(mp, dep->namelen);
+}
+
 /* Scrub a directory btree record. */
 STATIC int
 xchk_dir_rec(
@@ -389,21 +428,24 @@ xchk_dir_rec(
 		goto out_relse;
 	}
 	for (;;) {
-		struct xfs_dir2_data_entry	*dep = bp->b_addr + iter_off;
 		struct xfs_dir2_data_unused	*dup = bp->b_addr + iter_off;
+		int				advance;
 
 		if (iter_off >= end) {
 			xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
 			goto out_relse;
 		}
 
-		if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
-			iter_off += be16_to_cpu(dup->length);
-			continue;
-		}
-		if (dep == dent)
+		if (dup->freetag == cpu_to_be16(XFS_DIR2_DATA_FREE_TAG))
+			advance = xchk_dir_check_unused(ds, bp, iter_off, end);
+		else
+			advance = xchk_dir_check_entry(ds, bp, iter_off, end,
+					dent);
+		if (advance < 0)
+			goto out_relse;
+		if (!advance)
 			break;
-		iter_off += xfs_dir2_data_entsize(mp, dep->namelen);
+		iter_off += advance;
 	}
 
 	/* Retrieve the entry, sanity check it, and compare hashes. */
diff --git a/fs/xfs/scrub/dir_repair.c b/fs/xfs/scrub/dir_repair.c
index 9aafe5c31cbe3..f8e88b638c43d 100644
--- a/fs/xfs/scrub/dir_repair.c
+++ b/fs/xfs/scrub/dir_repair.c
@@ -462,6 +462,52 @@ xrep_dir_salvage_data_entry(
 	return xrep_dir_salvage_entry(rd, dep->name, dep->namelen, ino);
 }
 
+/*
+ * Deal with an unused directory entry.  Returns a positive number of bytes to
+ * advance in the directory block, or zero to stop processing.
+ */
+static int
+xrep_dir_recover_unused(
+	struct xfs_buf			*bp,
+	unsigned int			offset,
+	unsigned int			end)
+{
+	struct xfs_dir2_data_unused	*dup = bp->b_addr + offset;
+
+	return be16_to_cpu(dup->length);
+}
+
+/*
+ * Salvage a directory entry.  Returns a positive number of bytes to advance
+ * in the directory block, zero to stop processing, or a negative errno.
+ */
+static int
+xrep_dir_recover_entry(
+	struct xrep_dir			*rd,
+	struct xfs_buf			*bp,
+	unsigned int			offset,
+	unsigned int			end)
+{
+	struct xfs_dir2_data_entry	*dep = bp->b_addr + offset;
+	unsigned int			advance;
+	int				error;
+
+	/* Don't walk off the end of the block. */
+	advance = xfs_dir2_data_entsize(rd->sc->mp, dep->namelen);
+	if (!advance)
+		return 0;
+	if (offset + advance > end)
+		return 0;
+
+	/* Ok, let's save this entry. */
+	error = xrep_dir_salvage_data_entry(rd, dep);
+	if (error < 0)
+		return error;
+
+	return advance;
+}
+
+
 /* Try to recover block/data format directory entries. */
 STATIC int
 xrep_dir_recover_data(
@@ -483,33 +529,20 @@ xrep_dir_recover_data(
 
 	while (offset < end) {
 		struct xfs_dir2_data_unused	*dup = bp->b_addr + offset;
-		struct xfs_dir2_data_entry	*dep = bp->b_addr + offset;
-		unsigned int			advance;
+		int				advance;
 
 		if (xchk_should_terminate(rd->sc, &error))
 			return error;
 
-		/* Skip unused entries. */
-		if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
-			if (!dup->length)
-				break;
-			offset += be16_to_cpu(dup->length);
-			continue;
-		}
-
-		/* Don't walk off the end of the block. */
-		advance = xfs_dir2_data_entsize(rd->sc->mp, dep->namelen);
+		if (dup->freetag == cpu_to_be16(XFS_DIR2_DATA_FREE_TAG))
+			advance = xrep_dir_recover_unused(bp, offset, end);
+		else
+			advance = xrep_dir_recover_entry(rd, bp, offset, end);
+		if (advance < 0)
+			return advance;
 		if (!advance)
 			break;
 		offset += advance;
-		if (offset > end)
-			break;
-
-		/* Ok, let's save this entry. */
-		error = xrep_dir_salvage_data_entry(rd, dep);
-		if (error)
-			return error;
-
 	}
 
 	return 0;
-- 
2.53.0

[PATCH 6.18.y 2/2] xfs: improve dirent bounds checking in scrub and repair

[Sasha Levin]

From: "Darrick J. Wong" <djwong@kernel.org>

[ Upstream commit 5d470234d04dae6fe2ca2cf4b9ef277b78c7e05a ]

LOLLM complains that we don't do enough bounds checking of the directory
entries in directory blocks when we're looking for errors or trying to
salvage entries.  Let's improve that with more detailed checks.

Cc: stable@vger.kernel.org # v4.16
Fixes: ce92d29ddf9908 ("xfs: directory scrubber must walk through data block to offset")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Assisted-by: LOLLM # finding obvious bugs
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/xfs/scrub/dir.c        | 68 +++++++++++++++++++++++++++++++++------
 fs/xfs/scrub/dir_repair.c | 37 ++++++++++++++++++---
 2 files changed, 91 insertions(+), 14 deletions(-)

diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
index 2f73baee0f0b4..495fdf3b519ae 100644
--- a/fs/xfs/scrub/dir.c
+++ b/fs/xfs/scrub/dir.c
@@ -323,11 +323,24 @@ xchk_dir_check_unused(
 	struct xchk_da_btree		*ds,
 	struct xfs_buf			*bp,
 	unsigned int			iter_off,
-	unsigned int			end)
+	unsigned int			end,
+	xfs_dablk_t			rec_bno)
 {
 	struct xfs_dir2_data_unused	*dup = bp->b_addr + iter_off;
+	unsigned int			advance;
+
+	if (iter_off + sizeof(*dup) > end) {
+		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		return -1;
+	}
+
+	advance = xfs_dir2_data_unusedsize(be16_to_cpu(dup->length));
+	if (!advance || iter_off + advance > end) {
+		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		return -1;
+	}
 
-	return be16_to_cpu(dup->length);
+	return advance;
 }
 
 /*
@@ -341,15 +354,31 @@ xchk_dir_check_entry(
 	struct xfs_buf			*bp,
 	unsigned int			iter_off,
 	unsigned int			end,
-	struct xfs_dir2_data_entry	*dent)
+	struct xfs_dir2_data_entry	*dent,
+	xfs_dablk_t			rec_bno)
 {
 	struct xfs_dir2_data_entry	*dep = bp->b_addr + iter_off;
 	struct xfs_mount		*mp = ds->state->mp;
+	unsigned int			advance;
+
+	/* must have namelen */
+	advance = offsetof(typeof(*dep), name);
+	if (iter_off + advance >= end) {
+		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		return -1;
+	}
+
+	/* Don't walk off the end of the block. */
+	advance = xfs_dir2_data_entsize(mp, dep->namelen);
+	if (!advance || iter_off + advance > end) {
+		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		return -1;
+	}
 
 	if (dep == dent)
 		return 0;
 
-	return xfs_dir2_data_entsize(mp, dep->namelen);
+	return advance;
 }
 
 /* Scrub a directory btree record. */
@@ -377,6 +406,7 @@ xchk_dir_rec(
 	xfs_dahash_t			hash;
 	struct xfs_dir3_icleaf_hdr	hdr;
 	unsigned int			tag;
+	bool				foundit = false;
 	int				error;
 
 	ASSERT(blk->magic == XFS_DIR2_LEAF1_MAGIC ||
@@ -421,33 +451,44 @@ xchk_dir_rec(
 	dent = bp->b_addr + off;
 
 	/* Make sure we got a real directory entry. */
-	iter_off = geo->data_entry_offset;
 	end = xfs_dir3_data_end_offset(geo, bp->b_addr);
 	if (!end) {
 		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
 		goto out_relse;
 	}
-	for (;;) {
+	iter_off = geo->data_entry_offset;
+	while (iter_off < end) {
 		struct xfs_dir2_data_unused	*dup = bp->b_addr + iter_off;
 		int				advance;
 
-		if (iter_off >= end) {
+		/* must have freetag */
+		advance = offsetof(typeof(*dup), length);
+		if (iter_off + advance >= end) {
 			xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
 			goto out_relse;
 		}
 
 		if (dup->freetag == cpu_to_be16(XFS_DIR2_DATA_FREE_TAG))
-			advance = xchk_dir_check_unused(ds, bp, iter_off, end);
+			advance = xchk_dir_check_unused(ds, bp, iter_off, end,
+					rec_bno);
 		else
 			advance = xchk_dir_check_entry(ds, bp, iter_off, end,
-					dent);
+					dent, rec_bno);
 		if (advance < 0)
 			goto out_relse;
-		if (!advance)
+		if (!advance) {
+			foundit = true;
 			break;
+		}
 		iter_off += advance;
 	}
 
+	/* Hash tree must point to the exact dirent */
+	if (!foundit) {
+		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		goto out_relse;
+	}
+
 	/* Retrieve the entry, sanity check it, and compare hashes. */
 	ino = be64_to_cpu(dent->inumber);
 	hash = be32_to_cpu(ent->hashval);
@@ -459,6 +500,13 @@ xchk_dir_rec(
 		goto out_relse;
 	}
 
+	/* Name must not overflow end of block */
+	if ((char *)dent->name + dent->namelen >
+	    (char *)bp->b_addr + BBTOB(bp->b_length)) {
+		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		goto out_relse;
+	}
+
 	/* Does the directory hash match? */
 	dname.name = dent->name;
 	dname.len = dent->namelen;
diff --git a/fs/xfs/scrub/dir_repair.c b/fs/xfs/scrub/dir_repair.c
index f8e88b638c43d..c7fd39fd83a48 100644
--- a/fs/xfs/scrub/dir_repair.c
+++ b/fs/xfs/scrub/dir_repair.c
@@ -473,8 +473,16 @@ xrep_dir_recover_unused(
 	unsigned int			end)
 {
 	struct xfs_dir2_data_unused	*dup = bp->b_addr + offset;
+	unsigned int			advance;
+
+	if (offset + sizeof(*dup) > end)
+		return 0;
+
+	advance = xfs_dir2_data_unusedsize(be16_to_cpu(dup->length));
+	if (!advance || offset + advance > end)
+		return 0;
 
-	return be16_to_cpu(dup->length);
+	return advance;
 }
 
 /*
@@ -492,11 +500,14 @@ xrep_dir_recover_entry(
 	unsigned int			advance;
 	int				error;
 
+	/* must have namelen */
+	advance = offsetof(typeof(*dep), name);
+	if (offset + advance >= end)
+		return 0;
+
 	/* Don't walk off the end of the block. */
 	advance = xfs_dir2_data_entsize(rd->sc->mp, dep->namelen);
-	if (!advance)
-		return 0;
-	if (offset + advance > end)
+	if (!advance || offset + advance > end)
 		return 0;
 
 	/* Ok, let's save this entry. */
@@ -534,6 +545,11 @@ xrep_dir_recover_data(
 		if (xchk_should_terminate(rd->sc, &error))
 			return error;
 
+		/* must have freetag */
+		advance = offsetof(typeof(*dup), length);
+		if (offset + advance >= end)
+			break;
+
 		if (dup->freetag == cpu_to_be16(XFS_DIR2_DATA_FREE_TAG))
 			advance = xrep_dir_recover_unused(bp, offset, end);
 		else
@@ -565,6 +581,19 @@ xrep_dir_recover_sf(
 	hdr = ifp->if_data;
 	end = (unsigned char *)ifp->if_data + ifp->if_bytes;
 
+	/* sf header must be big enough for count/i8count */
+	if (!hdr || ifp->if_bytes < 2)
+		return 0;
+
+	/* and large enough for the parent inumber */
+	if (hdr->i8count) {
+		if (ifp->if_bytes < offsetof(struct xfs_dir2_sf_hdr, parent[8]))
+			return 0;
+	} else {
+		if (ifp->if_bytes < offsetof(struct xfs_dir2_sf_hdr, parent[4]))
+			return 0;
+	}
+
 	ino = xfs_dir2_sf_get_parent_ino(hdr);
 	trace_xrep_dir_salvaged_parent(rd->sc->ip, ino);
 
-- 
2.53.0