Thanks for finding this - I just put a patch in cifs-2.6.git for-next for this https://git.samba.org/?p=sfrench/cifs-2.6.git;a=commit;h=1dc92c450a53f120b67296cb4b29c1dfdc665ac1 On Mon, May 18, 2015 at 7:33 AM, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > [ I recently changed the checker so now it gives a new warning about > this old code. ] > > Hello Steve French, > > The patch 84ceeb962665: "[CIFS] fix static checker warning" from Jun > 26, 2013, leads to the following static checker warning: > > fs/cifs/smb2pdu.c:136 smb2_hdr_assemble() > warn: variable dereferenced before check 'tcon->ses->server' (see line 120) > > fs/cifs/smb2pdu.c > 111 /* GLOBAL_CAP_LARGE_MTU will only be set if dialect > SMB2.02 */ > 112 /* See sections 2.2.4 and 3.2.4.1.5 of MS-SMB2 */ > 113 if ((tcon->ses) && > 114 (tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU)) > ^^^^^^^^^^^^^^^^^ > Dereferenced without a check. > > 115 hdr->CreditCharge = cpu_to_le16(1); > 116 /* else CreditCharge MBZ */ > 117 > 118 hdr->TreeId = tcon->tid; > 119 /* Uid is not converted */ > 120 if (tcon->ses) > 121 hdr->SessionId = tcon->ses->Suid; > 122 > 123 /* > 124 * If we would set SMB2_FLAGS_DFS_OPERATIONS on open we also would have > 125 * to pass the path on the Open SMB prefixed by \\server\share. > 126 * Not sure when we would need to do the augmented path (if ever) and > 127 * setting this flag breaks the SMB2 open operation since it is > 128 * illegal to send an empty path name (without \\server\share prefix) > 129 * when the DFS flag is set in the SMB open header. We could > 130 * consider setting the flag on all operations other than open > 131 * but it is safer to net set it for now. > 132 */ > 133 /* if (tcon->share_flags & SHI1005_FLAGS_DFS) > 134 hdr->Flags |= SMB2_FLAGS_DFS_OPERATIONS; */ > 135 > 136 if (tcon->ses && tcon->ses->server && tcon->ses->server->sign) > ^^^^^^^^^^^^^^^^^ > > Checked too late. > > 137 hdr->Flags |= SMB2_FLAGS_SIGNED; > 138 out: > 139 pdu->StructureSize2 = cpu_to_le16(parmsize); > 140 return; > > regards, > dan carpenter -- Thanks, Steve -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
