| Message ID | 20190902151059.22088-1-colin.king@canonical.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [V2,cifs-next] cifs: fix dereference on ses before it is null checked | expand |
Tentatively merged into cifs-2.6.git pending additional testing Kicked off buildbot with rc7+patches in cifs for-next See http://smb3-test-rhel-75.southcentralus.cloudapp.azure.com/#/builders/2/builds/247 On Mon, Sep 2, 2019 at 10:33 AM Colin King <colin.king@canonical.com> wrote: > > From: Colin Ian King <colin.king@canonical.com> > > The assignment of pointer server dereferences pointer ses, however, > this dereference occurs before ses is null checked and hence we > have a potential null pointer dereference. Fix this by only > dereferencing ses after it has been null checked. > > Addresses-Coverity: ("Dereference before null check") > Fixes: 2808c6639104 ("cifs: add new debugging macro cifs_server_dbg") > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > fs/cifs/smb2pdu.c | 11 ++++++++--- > fs/cifs/transport.c | 3 ++- > 2 files changed, 10 insertions(+), 4 deletions(-) > > diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c > index dbc6ef50dd45..0e92983de0b7 100644 > --- a/fs/cifs/smb2pdu.c > +++ b/fs/cifs/smb2pdu.c > @@ -2759,8 +2759,10 @@ SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid, > else > return -EIO; > > + if (!ses) > + return -EIO; > server = ses->server; > - if (!ses || !(server)) > + if (!server) > return -EIO; > > if (smb3_encryption_required(tcon)) > @@ -3058,13 +3060,16 @@ query_info(const unsigned int xid, struct cifs_tcon *tcon, > int rc = 0; > int resp_buftype = CIFS_NO_BUFFER; > struct cifs_ses *ses = tcon->ses; > - struct TCP_Server_Info *server = ses->server; > + struct TCP_Server_Info *server; > int flags = 0; > bool allocated = false; > > cifs_dbg(FYI, "Query Info\n"); > > - if (!ses || !(server)) > + if (!ses) > + return -EIO; > + server = ses->server; > + if (!server) > return -EIO; > > if (smb3_encryption_required(tcon)) > diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c > index 0d60bd2f4dca..a90bd4d75b4d 100644 > --- a/fs/cifs/transport.c > +++ b/fs/cifs/transport.c > @@ -1242,12 +1242,13 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses, > struct kvec iov = { .iov_base = in_buf, .iov_len = len }; > struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 }; > struct cifs_credits credits = { .value = 1, .instance = 0 }; > - struct TCP_Server_Info *server = ses->server; > + struct TCP_Server_Info *server; > > if (ses == NULL) { > cifs_dbg(VFS, "Null smb session\n"); > return -EIO; > } > + server = ses->server; > if (server == NULL) { > cifs_dbg(VFS, "Null tcp session\n"); > return -EIO; > -- > 2.20.1 >
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index dbc6ef50dd45..0e92983de0b7 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -2759,8 +2759,10 @@ SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid, else return -EIO; + if (!ses) + return -EIO; server = ses->server; - if (!ses || !(server)) + if (!server) return -EIO; if (smb3_encryption_required(tcon)) @@ -3058,13 +3060,16 @@ query_info(const unsigned int xid, struct cifs_tcon *tcon, int rc = 0; int resp_buftype = CIFS_NO_BUFFER; struct cifs_ses *ses = tcon->ses; - struct TCP_Server_Info *server = ses->server; + struct TCP_Server_Info *server; int flags = 0; bool allocated = false; cifs_dbg(FYI, "Query Info\n"); - if (!ses || !(server)) + if (!ses) + return -EIO; + server = ses->server; + if (!server) return -EIO; if (smb3_encryption_required(tcon)) diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index 0d60bd2f4dca..a90bd4d75b4d 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -1242,12 +1242,13 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses, struct kvec iov = { .iov_base = in_buf, .iov_len = len }; struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 }; struct cifs_credits credits = { .value = 1, .instance = 0 }; - struct TCP_Server_Info *server = ses->server; + struct TCP_Server_Info *server; if (ses == NULL) { cifs_dbg(VFS, "Null smb session\n"); return -EIO; } + server = ses->server; if (server == NULL) { cifs_dbg(VFS, "Null tcp session\n"); return -EIO;