In the smb2_send_interim_resp(), if ksmbd_alloc_work_struct()
fails to allocate a node, it returns a NULL pointer to the
in_work pointer. This can lead to an illegal memory write of
in_work->response_buf when allocate_interim_rsp_buf() attempts
to perform a kzalloc() on it.
To address this issue, incorporating a check for the return
value of ksmbd_alloc_work_struct() ensures that the function
returns immediately upon allocation failure, thereby preventing
the aforementioned illegal memory access.
Fixes: 041bba4414cd ("ksmbd: fix wrong interim response on compound")
Signed-off-by: Wentao Liang <liangwentao@xxxxxxxxxxx>
---
fs/smb/server/smb2pdu.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
index 599118aed205..6683ed3b7f18 100644
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -695,6 +695,9 @@ void smb2_send_interim_resp(struct ksmbd_work *work, __le32 status)
struct smb2_hdr *rsp_hdr;
struct ksmbd_work *in_work = ksmbd_alloc_work_struct();
+ if (!in_work)
+ return;
+
if (allocate_interim_rsp_buf(in_work)) {
pr_err("smb_allocate_rsp_buf failed!\n");
ksmbd_free_work_struct(in_work);
--
2.42.0.windows.2
