FAILED: patch "[PATCH] ocfs2: fix out-of-bounds write in ocfs2_write_end_inline" failed to apply to 6.18-stable tree

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 <[email protected]>.

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 7bc5da4842bed3252d26e742213741a4d0ac1b14
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026041350-tableware-passover-f18e@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

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

From 7bc5da4842bed3252d26e742213741a4d0ac1b14 Mon Sep 17 00:00:00 2001
From: Joseph Qi <[email protected]>
Date: Fri, 3 Apr 2026 14:38:30 +0800
Subject: [PATCH] ocfs2: fix out-of-bounds write in ocfs2_write_end_inline

KASAN reports a use-after-free write of 4086 bytes in ocfs2_write_end_inline, called from ocfs2_write_end_nolock during a copy_file_range splice fallback on a corrupted ocfs2 filesystem mounted on a loop device. The actual bug is an out-of-bounds write past the inode block buffer, not a true use-after-free. The write overflows into an adjacent freed page, which KASAN reports as UAF.

The root cause is that ocfs2_try_to_write_inline_data trusts the on-disk id_count field to determine whether a write fits in inline data. On a corrupted filesystem, id_count can exceed the physical maximum inline data capacity, causing writes to overflow the inode block buffer.

Call trace (crash path):

vfs_copy_file_range (fs/read_write.c:1634)

     do_splice_direct
       splice_direct_to_actor
         iter_file_splice_write
           ocfs2_file_write_iter
             generic_perform_write
               ocfs2_write_end
                 ocfs2_write_end_nolock (fs/ocfs2/aops.c:1949)
                   ocfs2_write_end_inline (fs/ocfs2/aops.c:1915)
                     memcpy_from_folio     <-- KASAN: write OOB

So add id_count upper bound check in ocfs2_validate_inode_block() to alongside the existing i_size check to fix it.

index 03a51662ea8e..a2ccd8011706 100644
@@ -1505,6 +1505,16 @@ int ocfs2_validate_inode_block(struct super_block *sb,
 			goto bail;
 		}
 
+		if (le16_to_cpu(data->id_count) >
+		    ocfs2_max_inline_data_with_xattr(sb, di)) {
+			rc = ocfs2_error(sb,
+					 "Invalid dinode #%llu: inline data id_count %u exceeds max %d\n",
+					 (unsigned long long)bh->b_blocknr,
+					 le16_to_cpu(data->id_count),
+					 ocfs2_max_inline_data_with_xattr(sb, di));
+			goto bail;
+		}
+
 		if (le64_to_cpu(di->i_size) > le16_to_cpu(data->id_count)) {
 			rc = ocfs2_error(sb,
 					 "Invalid dinode #%llu: inline data i_size %llu exceeds id_count %u\n",

From: Dmitry Antipov <[email protected]>

[ Upstream commit a2b1c419ff72ec62ff5831684e30cd1d4f0b09ee ]

In 'ocfs2_validate_inode_block()', add an extra check whether an inode with inline data (i.e. self-contained) has no clusters, thus preventing an invalid inode from being passed to 'ocfs2_evict_inode()' and below.

Stable-dep-of: 7bc5da4842be ("ocfs2: fix out-of-bounds write in ocfs2_write_end_inline")

---
 fs/ocfs2/inode.c | 8 ++++++++
 1 file changed, 8 insertions(+)

index 0a0a96054bfec..ef17f1bc741ef 100644
@@ -1505,6 +1505,14 @@ int ocfs2_validate_inode_block(struct super_block *sb,
 		goto bail;
 	}
 
+	if ((le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL) &&
+	    le32_to_cpu(di->i_clusters)) {
+		rc = ocfs2_error(sb, "Invalid dinode %llu: %u clusters\n",
+				 (unsigned long long)bh->b_blocknr,
+				 le32_to_cpu(di->i_clusters));
+		goto bail;
+	}
+
 	rc = 0;
 
 bail:

2.53.0

From: Deepanshu Kartikey <[email protected]>

[ Upstream commit 1524af3685b35feac76662cc551cbc37bd14775f ]

When reading an inode from disk, ocfs2_validate_inode_block() performs various sanity checks but does not validate the size of inline data. If the filesystem is corrupted, an inode's i_size can exceed the actual inline data capacity (id_count).

This causes ocfs2_dir_foreach_blk_id() to iterate beyond the inline data buffer, triggering a use-after-free when accessing directory entries from freed memory.

In the syzbot report:
- i_size was 1099511627576 bytes (~1TB)
- Actual inline data capacity (id_count) is typically <256 bytes
- A garbage rec_len (54648) caused ctx->pos to jump out of bounds
- This triggered a UAF in ocfs2_check_dir_entry()

Fix by adding a validation check in ocfs2_validate_inode_block() to ensure inodes with inline data have i_size <= id_count. This catches the corruption early during inode read and prevents all downstream code from operating on invalid data.

Stable-dep-of: 7bc5da4842be ("ocfs2: fix out-of-bounds write in ocfs2_write_end_inline")

---
 fs/ocfs2/inode.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

index ef17f1bc741ef..e7d130f024f91 100644
@@ -1505,12 +1505,25 @@ int ocfs2_validate_inode_block(struct super_block *sb,
 		goto bail;
 	}
 
-	if ((le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL) &&
-	    le32_to_cpu(di->i_clusters)) {
-		rc = ocfs2_error(sb, "Invalid dinode %llu: %u clusters\n",
-				 (unsigned long long)bh->b_blocknr,
-				 le32_to_cpu(di->i_clusters));
-		goto bail;
+	if (le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL) {
+		struct ocfs2_inline_data *data = &di->id2.i_data;
+
+		if (le32_to_cpu(di->i_clusters)) {
+			rc = ocfs2_error(sb,
+					 "Invalid dinode %llu: %u clusters\n",
+					 (unsigned long long)bh->b_blocknr,
+					 le32_to_cpu(di->i_clusters));
+			goto bail;
+		}
+
+		if (le64_to_cpu(di->i_size) > le16_to_cpu(data->id_count)) {
+			rc = ocfs2_error(sb,
+					 "Invalid dinode #%llu: inline data i_size %llu exceeds id_count %u\n",
+					 (unsigned long long)bh->b_blocknr,
+					 (unsigned long long)le64_to_cpu(di->i_size),
+					 le16_to_cpu(data->id_count));
+			goto bail;
+		}
 	}
 
 	rc = 0;

2.53.0

From: Joseph Qi <[email protected]>

[ Upstream commit 7bc5da4842bed3252d26e742213741a4d0ac1b14 ]

KASAN reports a use-after-free write of 4086 bytes in ocfs2_write_end_inline, called from ocfs2_write_end_nolock during a copy_file_range splice fallback on a corrupted ocfs2 filesystem mounted on a loop device. The actual bug is an out-of-bounds write past the inode block buffer, not a true use-after-free. The write overflows into an adjacent freed page, which KASAN reports as UAF.

The root cause is that ocfs2_try_to_write_inline_data trusts the on-disk id_count field to determine whether a write fits in inline data. On a corrupted filesystem, id_count can exceed the physical maximum inline data capacity, causing writes to overflow the inode block buffer.

Call trace (crash path):

vfs_copy_file_range (fs/read_write.c:1634)

     do_splice_direct
       splice_direct_to_actor
         iter_file_splice_write
           ocfs2_file_write_iter
             generic_perform_write
               ocfs2_write_end
                 ocfs2_write_end_nolock (fs/ocfs2/aops.c:1949)
                   ocfs2_write_end_inline (fs/ocfs2/aops.c:1915)
                     memcpy_from_folio     <-- KASAN: write OOB

So add id_count upper bound check in ocfs2_validate_inode_block() to alongside the existing i_size check to fix it.

---
 fs/ocfs2/inode.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

index e7d130f024f91..a840dde611c01 100644
@@ -1516,6 +1516,16 @@ int ocfs2_validate_inode_block(struct super_block *sb,
 			goto bail;
 		}
 
+		if (le16_to_cpu(data->id_count) >
+		    ocfs2_max_inline_data_with_xattr(sb, di)) {
+			rc = ocfs2_error(sb,
+					 "Invalid dinode #%llu: inline data id_count %u exceeds max %d\n",
+					 (unsigned long long)bh->b_blocknr,
+					 le16_to_cpu(data->id_count),
+					 ocfs2_max_inline_data_with_xattr(sb, di));
+			goto bail;
+		}
+
 		if (le64_to_cpu(di->i_size) > le16_to_cpu(data->id_count)) {
 			rc = ocfs2_error(sb,
 					 "Invalid dinode #%llu: inline data i_size %llu exceeds id_count %u\n",

2.53.0