From: Steve French <smfrench@gmail.com>
To: zisenye@stu.xidian.edu.cn
Cc: linkinjeon@kernel.org, pc@manguebit.org,
ronniesahlberg@gmail.com, sprasad@microsoft.com, tom@talpey.com,
bharathsm@microsoft.com, senozhatsky@chromium.org,
dhowells@redhat.com, gregkh@linuxfoundation.org,
chenxiaosong@chenxiaosong.com, stable@vger.kernel.org,
linux-cifs@vger.kernel.org
Subject: Re: [PATCH v4 1/1] smb/client: fix out-of-bounds read in smb2_compound_op()
Date: Wed, 6 May 2026 11:03:55 -0500 [thread overview]
Message-ID: <CAH2r5msBgZn6QC20gR1p8pMMv-iTKabPbqU78O1MzfW2-1r+JA@mail.gmail.com> (raw)
In-Reply-To: <20260506034908.3874700-2-zisenye@stu.xidian.edu.cn>
merged into cifs-2.6.git for-next pending additional testing
On Tue, May 5, 2026 at 10:49 PM <zisenye@stu.xidian.edu.cn> wrote:
>
> From: Zisen Ye <zisenye@stu.xidian.edu.cn>
>
> If a server sends a truncated response but a large OutputBufferLength, and
> terminates the EA list early, check_wsl_eas() returns success without
> validating that the entire OutputBufferLength fits within iov_len.
>
> Then smb2_compound_op() does:
> memcpy(idata->wsl.eas, data[0], size[0]);
>
> Where size[0] is OutputBufferLength. If iov_len is smaller than size[0],
> memcpy can read beyond the end of the rsp_iov allocation and leak adjacent
> kernel heap memory.
>
> Link: https://lore.kernel.org/linux-cifs/d998240c-aca9-420d-9dbd-f5ba24af19e0@chenxiaosong.com/
> Fixes: ea41367b2a60 ("smb: client: introduce SMB2_OP_QUERY_WSL_EA")
> Cc: stable@vger.kernel.org
> Signed-off-by: Zisen Ye <zisenye@stu.xidian.edu.cn>
> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
> ---
> fs/smb/client/smb2inode.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/fs/smb/client/smb2inode.c b/fs/smb/client/smb2inode.c
> index 286912616c73..6c9c229b91f6 100644
> --- a/fs/smb/client/smb2inode.c
> +++ b/fs/smb/client/smb2inode.c
> @@ -111,7 +111,7 @@ static int check_wsl_eas(struct kvec *rsp_iov)
> u32 outlen, next;
> u16 vlen;
> u8 nlen;
> - u8 *end;
> + u8 *ea_end, *iov_end;
>
> outlen = le32_to_cpu(rsp->OutputBufferLength);
> if (outlen < SMB2_WSL_MIN_QUERY_EA_RESP_SIZE ||
> @@ -120,15 +120,19 @@ static int check_wsl_eas(struct kvec *rsp_iov)
>
> ea = (void *)((u8 *)rsp_iov->iov_base +
> le16_to_cpu(rsp->OutputBufferOffset));
> - end = (u8 *)rsp_iov->iov_base + rsp_iov->iov_len;
> + ea_end = (u8 *)ea + outlen;
> + iov_end = (u8 *)rsp_iov->iov_base + rsp_iov->iov_len;
> + if (ea_end > iov_end)
> + return -EINVAL;
> +
> for (;;) {
> - if ((u8 *)ea > end - sizeof(*ea))
> + if ((u8 *)ea > ea_end - sizeof(*ea))
> return -EINVAL;
>
> nlen = ea->ea_name_length;
> vlen = le16_to_cpu(ea->ea_value_length);
> if (nlen != SMB2_WSL_XATTR_NAME_LEN ||
> - (u8 *)ea->ea_data + nlen + 1 + vlen > end)
> + (u8 *)ea->ea_data + nlen + 1 + vlen > ea_end)
> return -EINVAL;
>
> switch (vlen) {
> --
> 2.54.0
>
--
Thanks,
Steve
prev parent reply other threads:[~2026-05-06 16:04 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-06 3:49 [PATCH v4 0/1] smb/client: fix out-of-bounds read zisenye
2026-05-06 3:49 ` [PATCH v4 1/1] smb/client: fix out-of-bounds read in smb2_compound_op() zisenye
2026-05-06 16:03 ` Steve French [this message]
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