diff mbox series

[RESEND,1/2] ocfs2: add bounds checking to ocfs2_xattr_find_entry()

Message ID 20240520024024.1976129-1-joseph.qi@linux.alibaba.com (mailing list archive)
State New
Headers show
Series [RESEND,1/2] ocfs2: add bounds checking to ocfs2_xattr_find_entry() | expand

Commit Message

Joseph Qi May 20, 2024, 2:40 a.m. UTC 
From: Ferry Meng <mengferry@linux.alibaba.com>

From: Ferry Meng <mengferry@linux.alibaba.com>

Add a paranoia check to make sure it doesn't stray beyond valid memory
region containing ocfs2 xattr entries when scanning for a match.
It will prevent out-of-bound access in case of crafted images.

Reported-by: lei lu <llfamsec@gmail.com>
Signed-off-by: Ferry Meng <mengferry@linux.alibaba.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
---
 fs/ocfs2/xattr.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

Comments

Andrew Morton May 22, 2024, 10:15 p.m. UTC | #1 
On Mon, 20 May 2024 10:40:23 +0800 Joseph Qi <joseph.qi@linux.alibaba.com> wrote:

> From: Ferry Meng <mengferry@linux.alibaba.com>
> 
> From: Ferry Meng <mengferry@linux.alibaba.com>
> 
> Add a paranoia check to make sure it doesn't stray beyond valid memory
> region containing ocfs2 xattr entries when scanning for a match.
> It will prevent out-of-bound access in case of crafted images.
> 
> Reported-by: lei lu <llfamsec@gmail.com>
> Signed-off-by: Ferry Meng <mengferry@linux.alibaba.com>
> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>

This should have had your signed-off-by, as you were on the patch
delivery path.  Documentation/process/submitting-patches.rst,
"Developer's Certificate of Origin 1.1".  I have made that change to
the mm.git copies of these two patches.
Joseph Qi May 23, 2024, 12:59 a.m. UTC | #2 
On 5/23/24 6:15 AM, Andrew Morton wrote:
> On Mon, 20 May 2024 10:40:23 +0800 Joseph Qi <joseph.qi@linux.alibaba.com> wrote:
> 
>> From: Ferry Meng <mengferry@linux.alibaba.com>
>>
>> From: Ferry Meng <mengferry@linux.alibaba.com>
>>
>> Add a paranoia check to make sure it doesn't stray beyond valid memory
>> region containing ocfs2 xattr entries when scanning for a match.
>> It will prevent out-of-bound access in case of crafted images.
>>
>> Reported-by: lei lu <llfamsec@gmail.com>
>> Signed-off-by: Ferry Meng <mengferry@linux.alibaba.com>
>> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
> 
> This should have had your signed-off-by, as you were on the patch
> delivery path.  Documentation/process/submitting-patches.rst,
> "Developer's Certificate of Origin 1.1".  I have made that change to
> the mm.git copies of these two patches.

Got it. Thanks for your time.
diff mbox series

Patch

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 3b81213ed7b8..8aea94c90739 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -1062,7 +1062,7 @@  ssize_t ocfs2_listxattr(struct dentry *dentry,
 	return i_ret + b_ret;
 }
 
-static int ocfs2_xattr_find_entry(int name_index,
+static int ocfs2_xattr_find_entry(struct inode *inode, int name_index,
 				  const char *name,
 				  struct ocfs2_xattr_search *xs)
 {
@@ -1076,6 +1076,10 @@  static int ocfs2_xattr_find_entry(int name_index,
 	name_len = strlen(name);
 	entry = xs->here;
 	for (i = 0; i < le16_to_cpu(xs->header->xh_count); i++) {
+		if ((void *)entry >= xs->end) {
+			ocfs2_error(inode->i_sb, "corrupted xattr entries");
+			return -EFSCORRUPTED;
+		}
 		cmp = name_index - ocfs2_xattr_get_type(entry);
 		if (!cmp)
 			cmp = name_len - entry->xe_name_len;
@@ -1166,7 +1170,7 @@  static int ocfs2_xattr_ibody_get(struct inode *inode,
 	xs->base = (void *)xs->header;
 	xs->here = xs->header->xh_entries;
 
-	ret = ocfs2_xattr_find_entry(name_index, name, xs);
+	ret = ocfs2_xattr_find_entry(inode, name_index, name, xs);
 	if (ret)
 		return ret;
 	size = le64_to_cpu(xs->here->xe_value_size);
@@ -2698,7 +2702,7 @@  static int ocfs2_xattr_ibody_find(struct inode *inode,
 
 	/* Find the named attribute. */
 	if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) {
-		ret = ocfs2_xattr_find_entry(name_index, name, xs);
+		ret = ocfs2_xattr_find_entry(inode, name_index, name, xs);
 		if (ret && ret != -ENODATA)
 			return ret;
 		xs->not_found = ret;
@@ -2833,7 +2837,7 @@  static int ocfs2_xattr_block_find(struct inode *inode,
 		xs->end = (void *)(blk_bh->b_data) + blk_bh->b_size;
 		xs->here = xs->header->xh_entries;
 
-		ret = ocfs2_xattr_find_entry(name_index, name, xs);
+		ret = ocfs2_xattr_find_entry(inode, name_index, name, xs);
 	} else
 		ret = ocfs2_xattr_index_block_find(inode, blk_bh,
 						   name_index,