Unverified Commit 3c675ddf authored by Zeng Heng's avatar Zeng Heng Committed by Konstantin Komarov
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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: be71b5cb ("fs/ntfs3: Add attrib operations")
Reported-by: default avatar <syzbot+9fcea5ef6dc4dc72d334@syzkaller.appspotmail.com>
Signed-off-by: default avatarZeng Heng <zengheng4@huawei.com>
[almaz.alexandrovich@paragon-software.com: lines of the patch have changed]
Signed-off-by: default avatarKonstantin Komarov <almaz.alexandrovich@paragon-software.com>
parent 6995e2de

fs/ntfs3/xattr.c

+3 −0
Original line number Diff line number Diff line
@@ -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;