From 3c675ddffb17a8b1e32efad5c983254af18b12c2 Mon Sep 17 00:00:00 2001 From: Zeng Heng Date: Thu, 8 Dec 2022 00:28:07 +0800 Subject: ntfs: Fix panic about slab-out-of-bounds caused by ntfs_listxattr() Here is a BUG report from syzbot: 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: 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 Fix the logic of ea_all iteration. When the ea->name_len is 0, return immediately, or Add2Ptr() would visit invalid memory in the next loop. Fixes: be71b5cba2e6 ("fs/ntfs3: Add attrib operations") Reported-by: syzbot+9fcea5ef6dc4dc72d334@syzkaller.appspotmail.com Signed-off-by: Zeng Heng [almaz.alexandrovich@paragon-software.com: lines of the patch have changed] Signed-off-by: Konstantin Komarov --- fs/ntfs3/xattr.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/ntfs3') diff --git a/fs/ntfs3/xattr.c b/fs/ntfs3/xattr.c index c3de60a4543f..fd02fcf4d409 100644 --- a/fs/ntfs3/xattr.c +++ b/fs/ntfs3/xattr.c @@ -214,6 +214,9 @@ static ssize_t ntfs_list_ea(struct ntfs_inode *ni, char *buffer, ea = Add2Ptr(ea_all, off); ea_size = unpacked_ea_size(ea); + if (!ea->name_len) + break; + if (buffer) { if (ret + ea->name_len + 1 > bytes_per_buffer) { err = -ERANGE; -- cgit v1.2.3