From: Enzo Matsumiya ematsumiya@suse.de
[ Upstream commit a4e430c8c8ba96be8c6ec4f2eb108bb8bcbee069 ]
Replace kfree with kfree_sensitive, or prepend memzero_explicit() in other cases, when freeing sensitive material that could still be left in memory.
Signed-off-by: Enzo Matsumiya ematsumiya@suse.de Reported-by: kernel test robot oliver.sang@intel.com Link: https://lore.kernel.org/r/202209201529.ec633796-oliver.sang@intel.com Reviewed-by: Paulo Alcantara (SUSE) pc@cjr.nz Reviewed-by: Ronnie Sahlberg lsahlber@redhat.com Signed-off-by: Steve French stfrench@microsoft.com Stable-dep-of: f7f291e14dde ("cifs: fix oops during encryption") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/cifs/cifsencrypt.c | 12 ++++++------ fs/cifs/connect.c | 6 +++--- fs/cifs/fs_context.c | 12 ++++++++++-- fs/cifs/misc.c | 2 +- fs/cifs/sess.c | 24 +++++++++++++++--------- fs/cifs/smb2ops.c | 6 +++--- fs/cifs/smb2pdu.c | 19 ++++++++++++++----- 7 files changed, 52 insertions(+), 29 deletions(-)
diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c index 46f5718754f9..d848bc0aac27 100644 --- a/fs/cifs/cifsencrypt.c +++ b/fs/cifs/cifsencrypt.c @@ -679,7 +679,7 @@ setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp) unlock: cifs_server_unlock(ses->server); setup_ntlmv2_rsp_ret: - kfree(tiblob); + kfree_sensitive(tiblob);
return rc; } @@ -753,14 +753,14 @@ cifs_crypto_secmech_release(struct TCP_Server_Info *server) server->secmech.ccmaesdecrypt = NULL; }
- kfree(server->secmech.sdesccmacaes); + kfree_sensitive(server->secmech.sdesccmacaes); server->secmech.sdesccmacaes = NULL; - kfree(server->secmech.sdeschmacsha256); + kfree_sensitive(server->secmech.sdeschmacsha256); server->secmech.sdeschmacsha256 = NULL; - kfree(server->secmech.sdeschmacmd5); + kfree_sensitive(server->secmech.sdeschmacmd5); server->secmech.sdeschmacmd5 = NULL; - kfree(server->secmech.sdescmd5); + kfree_sensitive(server->secmech.sdescmd5); server->secmech.sdescmd5 = NULL; - kfree(server->secmech.sdescsha512); + kfree_sensitive(server->secmech.sdescsha512); server->secmech.sdescsha512 = NULL; } diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 317ca1be9c4c..816161f51b29 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -311,7 +311,7 @@ cifs_abort_connection(struct TCP_Server_Info *server) } server->sequence_number = 0; server->session_estab = false; - kfree(server->session_key.response); + kfree_sensitive(server->session_key.response); server->session_key.response = NULL; server->session_key.len = 0; server->lstrp = jiffies; @@ -1580,7 +1580,7 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
cifs_crypto_secmech_release(server);
- kfree(server->session_key.response); + kfree_sensitive(server->session_key.response); server->session_key.response = NULL; server->session_key.len = 0; kfree(server->hostname); @@ -4141,7 +4141,7 @@ cifs_setup_session(const unsigned int xid, struct cifs_ses *ses, if (ses->auth_key.response) { cifs_dbg(FYI, "Free previous auth_key.response = %p\n", ses->auth_key.response); - kfree(ses->auth_key.response); + kfree_sensitive(ses->auth_key.response); ses->auth_key.response = NULL; ses->auth_key.len = 0; } diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c index 0e13dec86b25..45119597c765 100644 --- a/fs/cifs/fs_context.c +++ b/fs/cifs/fs_context.c @@ -791,6 +791,13 @@ do { \ cifs_sb->ctx->field = NULL; \ } while (0)
+#define STEAL_STRING_SENSITIVE(cifs_sb, ctx, field) \ +do { \ + kfree_sensitive(ctx->field); \ + ctx->field = cifs_sb->ctx->field; \ + cifs_sb->ctx->field = NULL; \ +} while (0) + static int smb3_reconfigure(struct fs_context *fc) { struct smb3_fs_context *ctx = smb3_fc2context(fc); @@ -811,7 +818,7 @@ static int smb3_reconfigure(struct fs_context *fc) STEAL_STRING(cifs_sb, ctx, UNC); STEAL_STRING(cifs_sb, ctx, source); STEAL_STRING(cifs_sb, ctx, username); - STEAL_STRING(cifs_sb, ctx, password); + STEAL_STRING_SENSITIVE(cifs_sb, ctx, password); STEAL_STRING(cifs_sb, ctx, domainname); STEAL_STRING(cifs_sb, ctx, nodename); STEAL_STRING(cifs_sb, ctx, iocharset); @@ -1162,7 +1169,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc, } break; case Opt_pass: - kfree(ctx->password); + kfree_sensitive(ctx->password); ctx->password = NULL; if (strlen(param->string) == 0) break; @@ -1470,6 +1477,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc, return 0;
cifs_parse_mount_err: + kfree_sensitive(ctx->password); return -EINVAL; }
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index 35085fa86636..3a117e2269a0 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -1123,7 +1123,7 @@ cifs_alloc_hash(const char *name, void cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc) { - kfree(*sdesc); + kfree_sensitive(*sdesc); *sdesc = NULL; if (*shash) crypto_free_shash(*shash); diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c index 6a85136da27c..22e281bc65ad 100644 --- a/fs/cifs/sess.c +++ b/fs/cifs/sess.c @@ -1214,6 +1214,12 @@ sess_alloc_buffer(struct sess_data *sess_data, int wct) static void sess_free_buffer(struct sess_data *sess_data) { + int i; + + /* zero the session data before freeing, as it might contain sensitive info (keys, etc) */ + for (i = 0; i < 3; i++) + if (sess_data->iov[i].iov_base) + memzero_explicit(sess_data->iov[i].iov_base, sess_data->iov[i].iov_len);
free_rsp_buf(sess_data->buf0_type, sess_data->iov[0].iov_base); sess_data->buf0_type = CIFS_NO_BUFFER; @@ -1375,7 +1381,7 @@ sess_auth_ntlmv2(struct sess_data *sess_data) sess_data->result = rc; sess_data->func = NULL; sess_free_buffer(sess_data); - kfree(ses->auth_key.response); + kfree_sensitive(ses->auth_key.response); ses->auth_key.response = NULL; }
@@ -1514,7 +1520,7 @@ sess_auth_kerberos(struct sess_data *sess_data) sess_data->result = rc; sess_data->func = NULL; sess_free_buffer(sess_data); - kfree(ses->auth_key.response); + kfree_sensitive(ses->auth_key.response); ses->auth_key.response = NULL; }
@@ -1649,7 +1655,7 @@ sess_auth_rawntlmssp_negotiate(struct sess_data *sess_data) rc = decode_ntlmssp_challenge(bcc_ptr, blob_len, ses);
out_free_ntlmsspblob: - kfree(ntlmsspblob); + kfree_sensitive(ntlmsspblob); out: sess_free_buffer(sess_data);
@@ -1659,9 +1665,9 @@ sess_auth_rawntlmssp_negotiate(struct sess_data *sess_data) }
/* Else error. Cleanup */ - kfree(ses->auth_key.response); + kfree_sensitive(ses->auth_key.response); ses->auth_key.response = NULL; - kfree(ses->ntlmssp); + kfree_sensitive(ses->ntlmssp); ses->ntlmssp = NULL;
sess_data->func = NULL; @@ -1760,7 +1766,7 @@ sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data) }
out_free_ntlmsspblob: - kfree(ntlmsspblob); + kfree_sensitive(ntlmsspblob); out: sess_free_buffer(sess_data);
@@ -1768,9 +1774,9 @@ sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data) rc = sess_establish_session(sess_data);
/* Cleanup */ - kfree(ses->auth_key.response); + kfree_sensitive(ses->auth_key.response); ses->auth_key.response = NULL; - kfree(ses->ntlmssp); + kfree_sensitive(ses->ntlmssp); ses->ntlmssp = NULL;
sess_data->func = NULL; @@ -1846,7 +1852,7 @@ int CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses, rc = sess_data->result;
out: - kfree(sess_data); + kfree_sensitive(sess_data); return rc; } #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */ diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index b724bf42b540..2a0eb9b7dd7a 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -4432,11 +4432,11 @@ crypt_message(struct TCP_Server_Info *server, int num_rqst, if (!rc && enc) memcpy(&tr_hdr->Signature, sign, SMB2_SIGNATURE_SIZE);
- kfree(iv); + kfree_sensitive(iv); free_sg: - kfree(sg); + kfree_sensitive(sg); free_req: - kfree(req); + kfree_sensitive(req); return rc; }
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 92a1d0695ebd..dd1aeb2316ac 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -1345,6 +1345,13 @@ SMB2_sess_alloc_buffer(struct SMB2_sess_data *sess_data) static void SMB2_sess_free_buffer(struct SMB2_sess_data *sess_data) { + int i; + + /* zero the session data before freeing, as it might contain sensitive info (keys, etc) */ + for (i = 0; i < 2; i++) + if (sess_data->iov[i].iov_base) + memzero_explicit(sess_data->iov[i].iov_base, sess_data->iov[i].iov_len); + free_rsp_buf(sess_data->buf0_type, sess_data->iov[0].iov_base); sess_data->buf0_type = CIFS_NO_BUFFER; } @@ -1477,6 +1484,8 @@ SMB2_auth_kerberos(struct SMB2_sess_data *sess_data) out_put_spnego_key: key_invalidate(spnego_key); key_put(spnego_key); + if (rc) + kfree_sensitive(ses->auth_key.response); out: sess_data->result = rc; sess_data->func = NULL; @@ -1573,7 +1582,7 @@ SMB2_sess_auth_rawntlmssp_negotiate(struct SMB2_sess_data *sess_data) }
out: - kfree(ntlmssp_blob); + memzero_explicit(ntlmssp_blob, blob_length); SMB2_sess_free_buffer(sess_data); if (!rc) { sess_data->result = 0; @@ -1581,7 +1590,7 @@ SMB2_sess_auth_rawntlmssp_negotiate(struct SMB2_sess_data *sess_data) return; } out_err: - kfree(ses->ntlmssp); + kfree_sensitive(ses->ntlmssp); ses->ntlmssp = NULL; sess_data->result = rc; sess_data->func = NULL; @@ -1657,9 +1666,9 @@ SMB2_sess_auth_rawntlmssp_authenticate(struct SMB2_sess_data *sess_data) } #endif out: - kfree(ntlmssp_blob); + memzero_explicit(ntlmssp_blob, blob_length); SMB2_sess_free_buffer(sess_data); - kfree(ses->ntlmssp); + kfree_sensitive(ses->ntlmssp); ses->ntlmssp = NULL; sess_data->result = rc; sess_data->func = NULL; @@ -1737,7 +1746,7 @@ SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses, cifs_server_dbg(VFS, "signing requested but authenticated as guest\n"); rc = sess_data->result; out: - kfree(sess_data); + kfree_sensitive(sess_data); return rc; }