From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754887AbaCYRVN (ORCPT ); Tue, 25 Mar 2014 13:21:13 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:55803 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753241AbaCYRVL (ORCPT ); Tue, 25 Mar 2014 13:21:11 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Pavel Shilovsky , Steve French , Kamal Mostafa Subject: [PATCH 3.8 25/81] CIFS: Fix too big maxBuf size for SMB3 mounts Date: Tue, 25 Mar 2014 10:15:38 -0700 Message-Id: <1395767794-5012-26-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1395767794-5012-1-git-send-email-kamal@canonical.com> References: <1395767794-5012-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.20 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Pavel Shilovsky commit 2365c4eaf077c48574ab6f143960048fc0f31518 upstream. SMB3 servers can respond with MaxTransactSize of more than 4M that can cause a memory allocation error returned from kmalloc in a lock codepath. Also the client doesn't support multicredit requests now and allows buffer sizes of 65536 bytes only. Set MaxTransactSize to this maximum supported value. Signed-off-by: Pavel Shilovsky Acked-by: Jeff Layton Signed-off-by: Steve French Signed-off-by: Kamal Mostafa --- fs/cifs/smb2glob.h | 3 +++ fs/cifs/smb2ops.c | 14 ++++---------- fs/cifs/smb2pdu.c | 4 +++- 3 files changed, 10 insertions(+), 11 deletions(-) diff --git a/fs/cifs/smb2glob.h b/fs/cifs/smb2glob.h index 7c0e214..cc592ef 100644 --- a/fs/cifs/smb2glob.h +++ b/fs/cifs/smb2glob.h @@ -55,4 +55,7 @@ #define SMB2_NTLMV2_SESSKEY_SIZE (16) #define SMB2_HMACSHA256_SIZE (32) +/* Maximum buffer size value we can send with 1 credit */ +#define SMB2_MAX_BUFFER_SIZE 65536 + #endif /* _SMB2_GLOB_H */ diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index bceffe7..542efd2 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -181,11 +181,8 @@ smb2_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *volume_info) /* start with specified wsize, or default */ wsize = volume_info->wsize ? volume_info->wsize : CIFS_DEFAULT_IOSIZE; wsize = min_t(unsigned int, wsize, server->max_write); - /* - * limit write size to 2 ** 16, because we don't support multicredit - * requests now. - */ - wsize = min_t(unsigned int, wsize, 2 << 15); + /* set it to the maximum buffer size value we can send with 1 credit */ + wsize = min_t(unsigned int, wsize, SMB2_MAX_BUFFER_SIZE); return wsize; } @@ -199,11 +196,8 @@ smb2_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *volume_info) /* start with specified rsize, or default */ rsize = volume_info->rsize ? volume_info->rsize : CIFS_DEFAULT_IOSIZE; rsize = min_t(unsigned int, rsize, server->max_read); - /* - * limit write size to 2 ** 16, because we don't support multicredit - * requests now. - */ - rsize = min_t(unsigned int, rsize, 2 << 15); + /* set it to the maximum buffer size value we can send with 1 credit */ + rsize = min_t(unsigned int, rsize, SMB2_MAX_BUFFER_SIZE); return rsize; } diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 41d9d07..8a9b5df 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -407,7 +407,9 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses) } server->dialect = le16_to_cpu(rsp->DialectRevision); - server->maxBuf = le32_to_cpu(rsp->MaxTransactSize); + /* set it to the maximum buffer size value we can send with 1 credit */ + server->maxBuf = min_t(unsigned int, le32_to_cpu(rsp->MaxTransactSize), + SMB2_MAX_BUFFER_SIZE); server->max_read = le32_to_cpu(rsp->MaxReadSize); server->max_write = le32_to_cpu(rsp->MaxWriteSize); /* BB Do we need to validate the SecurityMode? */ -- 1.8.3.2