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Message-ID: <20230420074622.210011-1-zengheng4@huawei.com>
Date: Thu, 20 Apr 2023 15:46:22 +0800
From: Zeng Heng <zengheng4@...wei.com>
To: <almaz.alexandrovich@...agon-software.com>
CC: <weiyongjun1@...wei.com>, <xiexiuqi@...wei.com>,
<ntfs3@...ts.linux.dev>, <liwei391@...wei.com>,
<linux-kernel@...r.kernel.org>
Subject: [PATCH] fs/ntfs3: fix panic about slab-out-of-bounds caused by ntfs_list_ea()
Here is a BUG report about linux-6.1 from syzbot, but it still remains
within upstream:
BUG: KASAN: slab-out-of-bounds in ntfs_list_ea fs/ntfs3/xattr.c:191 [inline]
BUG: KASAN: slab-out-of-bounds in ntfs_listxattr+0x401/0x570 fs/ntfs3/xattr.c:710
Read of size 1 at addr ffff888021acaf3d by task syz-executor128/3632
Call Trace:
kasan_report+0x139/0x170 mm/kasan/report.c:495
ntfs_list_ea fs/ntfs3/xattr.c:191 [inline]
ntfs_listxattr+0x401/0x570 fs/ntfs3/xattr.c:710
vfs_listxattr fs/xattr.c:457 [inline]
listxattr+0x293/0x2d0 fs/xattr.c:804
path_listxattr fs/xattr.c:828 [inline]
__do_sys_llistxattr fs/xattr.c:846 [inline]
Before derefering field members of `ea` in unpacked_ea_size(), we need to
check whether the EA_FULL struct is located in access validate range.
Similarly, when derefering `ea->name` field member, we need to check
whethe the ea->name is located in access validate range, too.
Fixes: be71b5cba2e6 ("fs/ntfs3: Add attrib operations")
Reported-by: syzbot+9fcea5ef6dc4dc72d334@...kaller.appspotmail.com
Signed-off-by: Zeng Heng <zengheng4@...wei.com>
---
fs/ntfs3/xattr.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/ntfs3/xattr.c b/fs/ntfs3/xattr.c
index ff64302e87e5..27eb30453b9f 100644
--- a/fs/ntfs3/xattr.c
+++ b/fs/ntfs3/xattr.c
@@ -210,11 +210,15 @@ static ssize_t ntfs_list_ea(struct ntfs_inode *ni, char *buffer,
size = le32_to_cpu(info->size);
/* Enumerate all xattrs. */
- for (ret = 0, off = 0; off < size; off += ea_size) {
+ for (ret = 0, off = 0; off + sizeof(struct EA_FULL) < size; off += ea_size) {
ea = Add2Ptr(ea_all, off);
ea_size = unpacked_ea_size(ea);
if (buffer) {
+ /* Check if we can use field ea->name */
+ if (off + ea_size > size)
+ break;
+
if (ret + ea->name_len + 1 > bytes_per_buffer) {
err = -ERANGE;
goto out;
--
2.25.1
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