From: zisenye@stu.xidian.edu.cn
To: smfrench@gmail.com, 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
Cc: linux-cifs@vger.kernel.org
Subject: [PATCH v4 1/1] smb/client: fix out-of-bounds read in smb2_compound_op()
Date: Wed, 6 May 2026 11:49:08 +0800 [thread overview]
Message-ID: <20260506034908.3874700-2-zisenye@stu.xidian.edu.cn> (raw)
In-Reply-To: <20260506034908.3874700-1-zisenye@stu.xidian.edu.cn>
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
next prev parent reply other threads:[~2026-05-06 3:49 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 ` zisenye [this message]
2026-05-06 16:03 ` [PATCH v4 1/1] smb/client: fix out-of-bounds read in smb2_compound_op() Steve French
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