From: Zeng Heng zengheng4@huawei.com
[ Upstream commit 3c675ddffb17a8b1e32efad5c983254af18b12c2 ]
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 zengheng4@huawei.com [almaz.alexandrovich@paragon-software.com: lines of the patch have changed] Signed-off-by: Konstantin Komarov almaz.alexandrovich@paragon-software.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ntfs3/xattr.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/fs/ntfs3/xattr.c b/fs/ntfs3/xattr.c index 8847db0159084..63250a5aae0aa 100644 --- a/fs/ntfs3/xattr.c +++ b/fs/ntfs3/xattr.c @@ -178,6 +178,9 @@ static ssize_t ntfs_list_ea(struct ntfs_inode *ni, char *buffer, for (ret = 0, off = 0; off < size; off += unpacked_ea_size(ea)) { ea = Add2Ptr(ea_all, off);
+ if (!ea->name_len) + break; + if (buffer) { if (ret + ea->name_len + 1 > bytes_per_buffer) { err = -ERANGE;