From 1f6e167d6753fe3ea493cdc7f7de8d03147a4d39 Mon Sep 17 00:00:00 2001
From: Ferry Meng <mengferry@linux.alibaba.com>
Date: Mon, 20 May 2024 10:40:23 +0800
Subject: [PATCH] ocfs2: add bounds checking to ocfs2_xattr_find_entry()
[ Upstream commit 9e3041fecdc8f78a5900c3aa51d3d756e73264d6 ]
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.
Link: https://lkml.kernel.org/r/20240520024024.1976129-1-joseph.qi@linux.alibaba.com
Signed-off-by: Ferry Meng <mengferry@linux.alibaba.com>
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reported-by: lei lu <llfamsec@gmail.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: af77c4fc1871 ("ocfs2: strict bound check before memcmp in ocfs2_xattr_find_entry()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ocfs2/xattr.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index b562cfef888ad..e6220f7f7cf34 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,
--
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