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authorPavel Shilovsky <piastry@etersoft.ru>2014-02-14 13:31:02 +0400
committerSteve French <smfrench@gmail.com>2014-02-14 16:50:47 -0600
commit2365c4eaf077c48574ab6f143960048fc0f31518 (patch)
treed710354608b5fe6a559dc5c0045ab0e6104ffe28 /fs/cifs/smb2pdu.c
parent5d81de8e8667da7135d3a32a964087c0faf5483f (diff)
downloadlinux-2365c4eaf077c48574ab6f143960048fc0f31518.tar.bz2
CIFS: Fix too big maxBuf size for SMB3 mounts
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. Cc: stable@vger.kernel.org # 3.7+ Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
Diffstat (limited to 'fs/cifs/smb2pdu.c')
-rw-r--r--fs/cifs/smb2pdu.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index a3f7a9c3cc69..860344701067 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -413,7 +413,9 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
/* SMB2 only has an extended negflavor */
server->negflavor = CIFS_NEGFLAVOR_EXTENDED;
- 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? */