From 7d9a7f1f96cd617ee9e75bb22217c709038e26b8 Mon Sep 17 00:00:00 2001 From: Ye Bin Date: Thu, 14 May 2026 21:14:18 +0800 Subject: [PATCH] smb/client: fix possible infinite loop and oob read in symlink_data() On 32-bit architectures, the infinite loop is as follows: len = p->ErrorDataLength == 0xfffffff8 u8 *next = p->ErrorContextData + len next == p On 32-bit architectures, the out-of-bounds read is as follows: len = p->ErrorDataLength == 0xfffffff0 u8 *next = p->ErrorContextData + len next == (u8 *)p - 8 Reported-by: ChenXiaoSong Fixes: 76894f3e2f71 ("cifs: improve symlink handling for smb2+") Cc: stable@vger.kernel.org Signed-off-by: Ye Bin Reviewed-by: ChenXiaoSong Signed-off-by: Steve French --- fs/smb/client/smb2file.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/smb/client/smb2file.c b/fs/smb/client/smb2file.c index b292aa94a593..6860eff31693 100644 --- a/fs/smb/client/smb2file.c +++ b/fs/smb/client/smb2file.c @@ -49,6 +49,9 @@ static struct smb2_symlink_err_rsp *symlink_data(const struct kvec *iov) __func__, le32_to_cpu(p->ErrorId)); len = ALIGN(le32_to_cpu(p->ErrorDataLength), 8); + if (len > end - ((u8 *)p + sizeof(*p))) + return ERR_PTR(-EINVAL); + p = (struct smb2_error_context_rsp *)(p->ErrorContextData + len); } } else if (le32_to_cpu(err->ByteCount) >= sizeof(*sym) &&