* FAILED: patch "[PATCH] xfs: improve dirent bounds checking in scrub and repair" failed to apply to 6.1-stable tree
@ 2026-11-04 17:51 gregkh
2026-11-05 18:44 ` [PATCH 6.1.y] xfs: improve dirent bounds checking in scrub and repair Sasha Levin
0 siblings, 1 reply; 2+ messages in thread
From: gregkh @ 2026-11-04 17:51 UTC (permalink / raw)
To: djwong, cem, hch; +Cc: stable
The patch below does not apply to the 6.1-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-6.1.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 '2026110440-scrambler-rants-fb16@gregkh' --subject-prefix 'PATCH 6.1.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);
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH 6.1.y] xfs: improve dirent bounds checking in scrub and repair
2026-11-04 17:51 FAILED: patch "[PATCH] xfs: improve dirent bounds checking in scrub and repair" failed to apply to 6.1-stable tree gregkh
@ 2026-11-05 18:44 ` Sasha Levin
0 siblings, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2026-11-05 18:44 UTC (permalink / raw)
To: stable; +Cc: Darrick J. Wong, Christoph Hellwig, Carlos Maiolino, 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>
[ sashal: Inlined upstream helper checks into the existing xchk_dir_rec() loop because the helper refactor is absent. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/xfs/scrub/dir.c | 60 +++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 54 insertions(+), 6 deletions(-)
diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
index 5c87800ab223d..73f8449caa9d0 100644
--- a/fs/xfs/scrub/dir.c
+++ b/fs/xfs/scrub/dir.c
@@ -219,6 +219,7 @@ 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 ||
@@ -263,28 +264,67 @@ 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_entry *dep = bp->b_addr + iter_off;
struct xfs_dir2_data_unused *dup = bp->b_addr + iter_off;
+ unsigned 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 (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
- iter_off += be16_to_cpu(dup->length);
+ if (iter_off + sizeof(*dup) > end) {
+ xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK,
+ rec_bno);
+ goto out_relse;
+ }
+
+ 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);
+ goto out_relse;
+ }
+
+ iter_off += advance;
continue;
}
- if (dep == dent)
+
+ /* must have namelen */
+ advance = offsetof(typeof(*dep), name);
+ if (iter_off + advance >= end) {
+ xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+ goto out_relse;
+ }
+
+ /* 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);
+ goto out_relse;
+ }
+
+ if (dep == dent) {
+ foundit = true;
break;
- iter_off += xfs_dir2_data_entsize(mp, dep->namelen);
+ }
+ 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. */
@@ -297,6 +337,14 @@ xchk_dir_rec(
xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
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;
+ }
+
calc_hash = xfs_da_hashname(dent->name, dent->namelen);
if (calc_hash != hash)
xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
--
2.53.0
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2026-11-04 17:51 FAILED: patch "[PATCH] xfs: improve dirent bounds checking in scrub and repair" failed to apply to 6.1-stable tree gregkh
2026-11-05 18:44 ` [PATCH 6.1.y] xfs: improve dirent bounds checking in scrub and repair Sasha Levin
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