[PATCH AUTOSEL 5.2 090/123] SMB3: Fix potential memory leak when processing compound chain

[PATCH AUTOSEL 5.2 090/123] SMB3: Fix potential memory leak when processing compound chain

[Sasha Levin]

From: Pavel Shilovsky <pshilov@microsoft.com>

[ Upstream commit 3edeb4a4146dc3b54d6fa71b7ee0585cb52ebfdf ]

When a reconnect happens in the middle of processing a compound chain
the code leaks a buffer from the memory pool. Fix this by properly
checking for a return code and freeing buffers in case of error.

Also maintain a buf variable to be equal to either smallbuf or bigbuf
depending on a response buffer size while parsing a chain and when
returning to the caller.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/cifs/smb2ops.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 2ec37dc589a7b..ae10d6e297c3a 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -4015,7 +4015,6 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
 {
 	int ret, length;
 	char *buf = server->smallbuf;
-	char *tmpbuf;
 	struct smb2_sync_hdr *shdr;
 	unsigned int pdu_length = server->pdu_size;
 	unsigned int buf_size;
@@ -4045,18 +4044,15 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
 		return length;
 
 	next_is_large = server->large_buf;
- one_more:
+one_more:
 	shdr = (struct smb2_sync_hdr *)buf;
 	if (shdr->NextCommand) {
-		if (next_is_large) {
-			tmpbuf = server->bigbuf;
+		if (next_is_large)
 			next_buffer = (char *)cifs_buf_get();
-		} else {
-			tmpbuf = server->smallbuf;
+		else
 			next_buffer = (char *)cifs_small_buf_get();
-		}
 		memcpy(next_buffer,
-		       tmpbuf + le32_to_cpu(shdr->NextCommand),
+		       buf + le32_to_cpu(shdr->NextCommand),
 		       pdu_length - le32_to_cpu(shdr->NextCommand));
 	}
 
@@ -4085,12 +4081,21 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
 		pdu_length -= le32_to_cpu(shdr->NextCommand);
 		server->large_buf = next_is_large;
 		if (next_is_large)
-			server->bigbuf = next_buffer;
+			server->bigbuf = buf = next_buffer;
 		else
-			server->smallbuf = next_buffer;
-
-		buf += le32_to_cpu(shdr->NextCommand);
+			server->smallbuf = buf = next_buffer;
 		goto one_more;
+	} else if (ret != 0) {
+		/*
+		 * ret != 0 here means that we didn't get to handle_mid() thus
+		 * server->smallbuf and server->bigbuf are still valid. We need
+		 * to free next_buffer because it is not going to be used
+		 * anywhere.
+		 */
+		if (next_is_large)
+			free_rsp_buf(CIFS_LARGE_BUFFER, next_buffer);
+		else
+			free_rsp_buf(CIFS_SMALL_BUFFER, next_buffer);
 	}
 
 	return ret;
-- 
2.20.1

[PATCH AUTOSEL 5.2 091/123] SMB3: Kernel oops mounting a encryptData share with CONFIG_DEBUG_VIRTUAL

[Sasha Levin]

From: Sebastien Tisserant <stisserant@wallix.com>

[ Upstream commit ee9d66182392695535cc9fccfcb40c16f72de2a9 ]

Fix kernel oops when mounting a encryptData CIFS share with
CONFIG_DEBUG_VIRTUAL

Signed-off-by: Sebastien Tisserant <stisserant@wallix.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/cifs/smb2ops.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index ae10d6e297c3a..42de31d206169 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3439,7 +3439,15 @@ fill_transform_hdr(struct smb2_transform_hdr *tr_hdr, unsigned int orig_len,
 static inline void smb2_sg_set_buf(struct scatterlist *sg, const void *buf,
 				   unsigned int buflen)
 {
-	sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
+	void *addr;
+	/*
+	 * VMAP_STACK (at least) puts stack into the vmalloc address space
+	 */
+	if (is_vmalloc_addr(buf))
+		addr = vmalloc_to_page(buf);
+	else
+		addr = virt_to_page(buf);
+	sg_set_page(sg, addr, buflen, offset_in_page(buf));
 }
 
 /* Assumes the first rqst has a transform header as the first iov.
-- 
2.20.1