* Leaking path or inconsistency LSM checking observed in fs/net @ 2018-09-25 17:27 ` Tong Zhang 0 siblings, 0 replies; 13+ messages in thread From: Tong Zhang @ 2018-09-25 17:27 UTC (permalink / raw) To: mark, jlbec, keescook, davem, viro, dvlasenk, ccaulfie, teigland Cc: linux-kernel, ocfs2-devel, cluster-devel, linux-security-module, Wenbo Shen Kernel Version: 4.18.5 Problem Description: We found several leaking path or inconsistency LSM design issue in fs/net. Currently we can only observe sock creation from kernel and all bind/listen/connect are not sent to LSM. So, we think that those net/socket related stuff should all go through LSM check and being audited even it is not a user thread or process. Here’s an example where we have a check: in fs/ocfs2/cluster/tcp.c:2035 o2net_open_listening_sock() a sock is created using sock_create(), where a LSM check security_socket_create is called(net/socket.c:1242) And where we don’t have a check fs/ocfs2/cluster/tcp.c:2052 bind fs/ocfs2/cluster/tcp.c:2059 listen fs/dlm/lowcomms.c:1264 bind fs/dlm/lowcomms.c:1278 listen fs/dlm/lowcomms.c:1354 listen several places that use kernel_bind/kernel_listen/kernel_connect net/socket.c:3231 kernel_bind net/socket.c:3237 kernel_listen net/socket.c:3286 kernel_connect - Tong ^ permalink raw reply [flat|nested] 13+ messages in thread
* [Cluster-devel] Leaking path or inconsistency LSM checking observed in fs/net @ 2018-09-25 17:27 ` Tong Zhang 0 siblings, 0 replies; 13+ messages in thread From: Tong Zhang @ 2018-09-25 17:27 UTC (permalink / raw) To: cluster-devel.redhat.com Kernel Version: 4.18.5 Problem Description: We found several leaking path or inconsistency LSM design issue in fs/net. Currently we can only observe sock creation from kernel and all bind/listen/connect are not sent to LSM. So, we think that those net/socket related stuff should all go through LSM check and being audited even it is not a user thread or process. Here?s an example where we have a check: in fs/ocfs2/cluster/tcp.c:2035 o2net_open_listening_sock() a sock is created using sock_create(), where a LSM check security_socket_create is called(net/socket.c:1242) And where we don?t have a check fs/ocfs2/cluster/tcp.c:2052 bind fs/ocfs2/cluster/tcp.c:2059 listen fs/dlm/lowcomms.c:1264 bind fs/dlm/lowcomms.c:1278 listen fs/dlm/lowcomms.c:1354 listen several places that use kernel_bind/kernel_listen/kernel_connect net/socket.c:3231 kernel_bind net/socket.c:3237 kernel_listen net/socket.c:3286 kernel_connect - Tong ^ permalink raw reply [flat|nested] 13+ messages in thread
* Leaking path or inconsistency LSM checking observed in fs/net @ 2018-09-25 17:27 ` Tong Zhang 0 siblings, 0 replies; 13+ messages in thread From: Tong Zhang @ 2018-09-25 17:27 UTC (permalink / raw) To: linux-security-module Kernel Version: 4.18.5 Problem Description: We found several leaking path or inconsistency LSM design issue in fs/net. Currently we can only observe sock creation from kernel and all bind/listen/connect are not sent to LSM. So, we think that those net/socket related stuff should all go through LSM check and being audited even it is not a user thread or process. Here?s an example where we have a check: in fs/ocfs2/cluster/tcp.c:2035 o2net_open_listening_sock() a sock is created using sock_create(), where a LSM check security_socket_create is called(net/socket.c:1242) And where we don?t have a check fs/ocfs2/cluster/tcp.c:2052 bind fs/ocfs2/cluster/tcp.c:2059 listen fs/dlm/lowcomms.c:1264 bind fs/dlm/lowcomms.c:1278 listen fs/dlm/lowcomms.c:1354 listen several places that use kernel_bind/kernel_listen/kernel_connect net/socket.c:3231 kernel_bind net/socket.c:3237 kernel_listen net/socket.c:3286 kernel_connect - Tong ^ permalink raw reply [flat|nested] 13+ messages in thread
* Leaking path or inconsistency LSM checking observed in fs/net 2018-09-25 17:27 ` Tong Zhang (?) (?) @ 2018-09-25 18:44 ` Stephen Smalley -1 siblings, 0 replies; 13+ messages in thread From: Stephen Smalley @ 2018-09-25 18:44 UTC (permalink / raw) To: Tong Zhang, mark, jlbec, keescook, davem, viro, dvlasenk, ccaulfie, teigland Cc: linux-kernel, ocfs2-devel, cluster-devel, linux-security-module, Wenbo Shen, Paul Moore On 09/25/2018 01:27 PM, Tong Zhang wrote: > Kernel Version: 4.18.5 > > Problem Description: > > We found several leaking path or inconsistency LSM design issue in fs/net. > > Currently we can only observe sock creation from kernel and all bind/listen/connect are not sent to LSM. > So, we think that those net/socket related stuff should all go through LSM check and being audited > even it is not a user thread or process. > > > Here’s an example where we have a check: > in fs/ocfs2/cluster/tcp.c:2035 o2net_open_listening_sock() a sock is created using sock_create(), > where a LSM check security_socket_create is called(net/socket.c:1242) > > > And where we don’t have a check > > fs/ocfs2/cluster/tcp.c:2052 bind > fs/ocfs2/cluster/tcp.c:2059 listen > > fs/dlm/lowcomms.c:1264 bind > fs/dlm/lowcomms.c:1278 listen > fs/dlm/lowcomms.c:1354 listen > > several places that use kernel_bind/kernel_listen/kernel_connect > > net/socket.c:3231 kernel_bind > net/socket.c:3237 kernel_listen > net/socket.c:3286 kernel_connect That's intentional. LSM isn't trying to mediate kernel-internal operations, and we do not want to apply permission checks against the credentials of the current userspace process for such operations. ocfs2 should likely be using sock_create_kern. ^ permalink raw reply [flat|nested] 13+ messages in thread
* [Cluster-devel] Leaking path or inconsistency LSM checking observed in fs/net @ 2018-09-25 18:44 ` Stephen Smalley 0 siblings, 0 replies; 13+ messages in thread From: Stephen Smalley @ 2018-09-25 18:44 UTC (permalink / raw) To: cluster-devel.redhat.com On 09/25/2018 01:27 PM, Tong Zhang wrote: > Kernel Version: 4.18.5 > > Problem Description: > > We found several leaking path or inconsistency LSM design issue in fs/net. > > Currently we can only observe sock creation from kernel and all bind/listen/connect are not sent to LSM. > So, we think that those net/socket related stuff should all go through LSM check and being audited > even it is not a user thread or process. > > > Here?s an example where we have a check: > in fs/ocfs2/cluster/tcp.c:2035 o2net_open_listening_sock() a sock is created using sock_create(), > where a LSM check security_socket_create is called(net/socket.c:1242) > > > And where we don?t have a check > > fs/ocfs2/cluster/tcp.c:2052 bind > fs/ocfs2/cluster/tcp.c:2059 listen > > fs/dlm/lowcomms.c:1264 bind > fs/dlm/lowcomms.c:1278 listen > fs/dlm/lowcomms.c:1354 listen > > several places that use kernel_bind/kernel_listen/kernel_connect > > net/socket.c:3231 kernel_bind > net/socket.c:3237 kernel_listen > net/socket.c:3286 kernel_connect That's intentional. LSM isn't trying to mediate kernel-internal operations, and we do not want to apply permission checks against the credentials of the current userspace process for such operations. ocfs2 should likely be using sock_create_kern. ^ permalink raw reply [flat|nested] 13+ messages in thread
* [Ocfs2-devel] Leaking path or inconsistency LSM checking observed in fs/net @ 2018-09-25 18:44 ` Stephen Smalley 0 siblings, 0 replies; 13+ messages in thread From: Stephen Smalley @ 2018-09-25 18:44 UTC (permalink / raw) To: linux-security-module On 09/25/2018 01:27 PM, Tong Zhang wrote: > Kernel Version: 4.18.5 > > Problem Description: > > We found several leaking path or inconsistency LSM design issue in fs/net. > > Currently we can only observe sock creation from kernel and all bind/listen/connect are not sent to LSM. > So, we think that those net/socket related stuff should all go through LSM check and being audited > even it is not a user thread or process. > > > Here?s an example where we have a check: > in fs/ocfs2/cluster/tcp.c:2035 o2net_open_listening_sock() a sock is created using sock_create(), > where a LSM check security_socket_create is called(net/socket.c:1242) > > > And where we don?t have a check > > fs/ocfs2/cluster/tcp.c:2052 bind > fs/ocfs2/cluster/tcp.c:2059 listen > > fs/dlm/lowcomms.c:1264 bind > fs/dlm/lowcomms.c:1278 listen > fs/dlm/lowcomms.c:1354 listen > > several places that use kernel_bind/kernel_listen/kernel_connect > > net/socket.c:3231 kernel_bind > net/socket.c:3237 kernel_listen > net/socket.c:3286 kernel_connect That's intentional. LSM isn't trying to mediate kernel-internal operations, and we do not want to apply permission checks against the credentials of the current userspace process for such operations. ocfs2 should likely be using sock_create_kern. ^ permalink raw reply [flat|nested] 13+ messages in thread
* Leaking path or inconsistency LSM checking observed in fs/net @ 2018-09-25 18:44 ` Stephen Smalley 0 siblings, 0 replies; 13+ messages in thread From: Stephen Smalley @ 2018-09-25 18:44 UTC (permalink / raw) To: linux-security-module On 09/25/2018 01:27 PM, Tong Zhang wrote: > Kernel Version: 4.18.5 > > Problem Description: > > We found several leaking path or inconsistency LSM design issue in fs/net. > > Currently we can only observe sock creation from kernel and all bind/listen/connect are not sent to LSM. > So, we think that those net/socket related stuff should all go through LSM check and being audited > even it is not a user thread or process. > > > Here?s an example where we have a check: > in fs/ocfs2/cluster/tcp.c:2035 o2net_open_listening_sock() a sock is created using sock_create(), > where a LSM check security_socket_create is called(net/socket.c:1242) > > > And where we don?t have a check > > fs/ocfs2/cluster/tcp.c:2052 bind > fs/ocfs2/cluster/tcp.c:2059 listen > > fs/dlm/lowcomms.c:1264 bind > fs/dlm/lowcomms.c:1278 listen > fs/dlm/lowcomms.c:1354 listen > > several places that use kernel_bind/kernel_listen/kernel_connect > > net/socket.c:3231 kernel_bind > net/socket.c:3237 kernel_listen > net/socket.c:3286 kernel_connect That's intentional. LSM isn't trying to mediate kernel-internal operations, and we do not want to apply permission checks against the credentials of the current userspace process for such operations. ocfs2 should likely be using sock_create_kern. ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: Leaking path or inconsistency LSM checking observed in fs/net 2018-09-25 18:44 ` Stephen Smalley (?) @ 2018-09-25 23:36 ` TongZhang -1 siblings, 0 replies; 13+ messages in thread From: TongZhang @ 2018-09-25 23:36 UTC (permalink / raw) To: Stephen Smalley Cc: mark, jlbec, keescook, davem, viro, dvlasenk, ccaulfie, teigland, LKML, ocfs2-devel, cluster-devel, linux-security-module, Wenbo Shen, Paul Moore ocfs2 is using sock_create instead of sock_create_kern in kernel v4.18.5. fs/ocfs2/cluster/tcp.c: 1636 https://elixir.bootlin.com/linux/v4.18.5/source/fs/ocfs2/cluster/tcp.c#L1636 >ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); fs/ocfs2/cluster/tcp.c: 2035 https://elixir.bootlin.com/linux/v4.18.5/source/fs/ocfs2/cluster/tcp.c#L2035 >ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); > On Sep 25, 2018, at 2:44 PM, Stephen Smalley <sds@tycho.nsa.gov> wrote: > > On 09/25/2018 01:27 PM, Tong Zhang wrote: >> Kernel Version: 4.18.5 >> Problem Description: >> We found several leaking path or inconsistency LSM design issue in fs/net. >> Currently we can only observe sock creation from kernel and all bind/listen/connect are not sent to LSM. >> So, we think that those net/socket related stuff should all go through LSM check and being audited >> even it is not a user thread or process. >> Here’s an example where we have a check: >> in fs/ocfs2/cluster/tcp.c:2035 o2net_open_listening_sock() a sock is created using sock_create(), >> where a LSM check security_socket_create is called(net/socket.c:1242) >> And where we don’t have a check >> fs/ocfs2/cluster/tcp.c:2052 bind >> fs/ocfs2/cluster/tcp.c:2059 listen >> fs/dlm/lowcomms.c:1264 bind >> fs/dlm/lowcomms.c:1278 listen >> fs/dlm/lowcomms.c:1354 listen >> several places that use kernel_bind/kernel_listen/kernel_connect >> net/socket.c:3231 kernel_bind >> net/socket.c:3237 kernel_listen >> net/socket.c:3286 kernel_connect > > That's intentional. LSM isn't trying to mediate kernel-internal operations, and we do not want to apply permission checks against the credentials of the current userspace process for such operations. ocfs2 should likely be using sock_create_kern. > ^ permalink raw reply [flat|nested] 13+ messages in thread
* [Cluster-devel] Leaking path or inconsistency LSM checking observed in fs/net @ 2018-09-25 23:36 ` TongZhang 0 siblings, 0 replies; 13+ messages in thread From: TongZhang @ 2018-09-25 23:36 UTC (permalink / raw) To: cluster-devel.redhat.com ocfs2 is using sock_create instead of sock_create_kern in kernel v4.18.5. fs/ocfs2/cluster/tcp.c: 1636 https://elixir.bootlin.com/linux/v4.18.5/source/fs/ocfs2/cluster/tcp.c#L1636 >ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); fs/ocfs2/cluster/tcp.c: 2035 https://elixir.bootlin.com/linux/v4.18.5/source/fs/ocfs2/cluster/tcp.c#L2035 >ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); > On Sep 25, 2018, at 2:44 PM, Stephen Smalley <sds@tycho.nsa.gov> wrote: > > On 09/25/2018 01:27 PM, Tong Zhang wrote: >> Kernel Version: 4.18.5 >> Problem Description: >> We found several leaking path or inconsistency LSM design issue in fs/net. >> Currently we can only observe sock creation from kernel and all bind/listen/connect are not sent to LSM. >> So, we think that those net/socket related stuff should all go through LSM check and being audited >> even it is not a user thread or process. >> Here?s an example where we have a check: >> in fs/ocfs2/cluster/tcp.c:2035 o2net_open_listening_sock() a sock is created using sock_create(), >> where a LSM check security_socket_create is called(net/socket.c:1242) >> And where we don?t have a check >> fs/ocfs2/cluster/tcp.c:2052 bind >> fs/ocfs2/cluster/tcp.c:2059 listen >> fs/dlm/lowcomms.c:1264 bind >> fs/dlm/lowcomms.c:1278 listen >> fs/dlm/lowcomms.c:1354 listen >> several places that use kernel_bind/kernel_listen/kernel_connect >> net/socket.c:3231 kernel_bind >> net/socket.c:3237 kernel_listen >> net/socket.c:3286 kernel_connect > > That's intentional. LSM isn't trying to mediate kernel-internal operations, and we do not want to apply permission checks against the credentials of the current userspace process for such operations. ocfs2 should likely be using sock_create_kern. > ^ permalink raw reply [flat|nested] 13+ messages in thread
* Leaking path or inconsistency LSM checking observed in fs/net @ 2018-09-25 23:36 ` TongZhang 0 siblings, 0 replies; 13+ messages in thread From: TongZhang @ 2018-09-25 23:36 UTC (permalink / raw) To: linux-security-module ocfs2 is using sock_create instead of sock_create_kern in kernel v4.18.5. fs/ocfs2/cluster/tcp.c: 1636 https://elixir.bootlin.com/linux/v4.18.5/source/fs/ocfs2/cluster/tcp.c#L1636 >ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); fs/ocfs2/cluster/tcp.c: 2035 https://elixir.bootlin.com/linux/v4.18.5/source/fs/ocfs2/cluster/tcp.c#L2035 >ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); > On Sep 25, 2018, at 2:44 PM, Stephen Smalley <sds@tycho.nsa.gov> wrote: > > On 09/25/2018 01:27 PM, Tong Zhang wrote: >> Kernel Version: 4.18.5 >> Problem Description: >> We found several leaking path or inconsistency LSM design issue in fs/net. >> Currently we can only observe sock creation from kernel and all bind/listen/connect are not sent to LSM. >> So, we think that those net/socket related stuff should all go through LSM check and being audited >> even it is not a user thread or process. >> Here?s an example where we have a check: >> in fs/ocfs2/cluster/tcp.c:2035 o2net_open_listening_sock() a sock is created using sock_create(), >> where a LSM check security_socket_create is called(net/socket.c:1242) >> And where we don?t have a check >> fs/ocfs2/cluster/tcp.c:2052 bind >> fs/ocfs2/cluster/tcp.c:2059 listen >> fs/dlm/lowcomms.c:1264 bind >> fs/dlm/lowcomms.c:1278 listen >> fs/dlm/lowcomms.c:1354 listen >> several places that use kernel_bind/kernel_listen/kernel_connect >> net/socket.c:3231 kernel_bind >> net/socket.c:3237 kernel_listen >> net/socket.c:3286 kernel_connect > > That's intentional. LSM isn't trying to mediate kernel-internal operations, and we do not want to apply permission checks against the credentials of the current userspace process for such operations. ocfs2 should likely be using sock_create_kern. > ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: Leaking path or inconsistency LSM checking observed in fs/net 2018-09-25 23:36 ` TongZhang (?) @ 2018-09-26 13:09 ` Stephen Smalley -1 siblings, 0 replies; 13+ messages in thread From: Stephen Smalley @ 2018-09-26 13:09 UTC (permalink / raw) To: TongZhang Cc: keescook, davem, dvlasenk, ccaulfie, teigland, LKML, ocfs2-devel, cluster-devel, linux-security-module, Wenbo Shen, Paul Moore On 09/25/2018 07:36 PM, TongZhang wrote: > ocfs2 is using sock_create instead of sock_create_kern in kernel v4.18.5. > > fs/ocfs2/cluster/tcp.c: 1636 > https://elixir.bootlin.com/linux/v4.18.5/source/fs/ocfs2/cluster/tcp.c#L1636 >> ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); > > fs/ocfs2/cluster/tcp.c: 2035 > https://elixir.bootlin.com/linux/v4.18.5/source/fs/ocfs2/cluster/tcp.c#L2035 >> ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); Yes, I think that's the real bug here. Unless the socket is in fact exposed for direct use by userspace, it ought to be using sock_create_kern() or similar. I would suggest that you verify that the socket is never returned to userspace, and then submit a patch switching the code to using sock_create_kern(). > > >> On Sep 25, 2018, at 2:44 PM, Stephen Smalley <sds@tycho.nsa.gov> wrote: >> >> On 09/25/2018 01:27 PM, Tong Zhang wrote: >>> Kernel Version: 4.18.5 >>> Problem Description: >>> We found several leaking path or inconsistency LSM design issue in fs/net. >>> Currently we can only observe sock creation from kernel and all bind/listen/connect are not sent to LSM. >>> So, we think that those net/socket related stuff should all go through LSM check and being audited >>> even it is not a user thread or process. >>> Here’s an example where we have a check: >>> in fs/ocfs2/cluster/tcp.c:2035 o2net_open_listening_sock() a sock is created using sock_create(), >>> where a LSM check security_socket_create is called(net/socket.c:1242) >>> And where we don’t have a check >>> fs/ocfs2/cluster/tcp.c:2052 bind >>> fs/ocfs2/cluster/tcp.c:2059 listen >>> fs/dlm/lowcomms.c:1264 bind >>> fs/dlm/lowcomms.c:1278 listen >>> fs/dlm/lowcomms.c:1354 listen >>> several places that use kernel_bind/kernel_listen/kernel_connect >>> net/socket.c:3231 kernel_bind >>> net/socket.c:3237 kernel_listen >>> net/socket.c:3286 kernel_connect >> >> That's intentional. LSM isn't trying to mediate kernel-internal operations, and we do not want to apply permission checks against the credentials of the current userspace process for such operations. ocfs2 should likely be using sock_create_kern. >> > ^ permalink raw reply [flat|nested] 13+ messages in thread
* [Cluster-devel] Leaking path or inconsistency LSM checking observed in fs/net @ 2018-09-26 13:09 ` Stephen Smalley 0 siblings, 0 replies; 13+ messages in thread From: Stephen Smalley @ 2018-09-26 13:09 UTC (permalink / raw) To: cluster-devel.redhat.com On 09/25/2018 07:36 PM, TongZhang wrote: > ocfs2 is using sock_create instead of sock_create_kern in kernel v4.18.5. > > fs/ocfs2/cluster/tcp.c: 1636 > https://elixir.bootlin.com/linux/v4.18.5/source/fs/ocfs2/cluster/tcp.c#L1636 >> ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); > > fs/ocfs2/cluster/tcp.c: 2035 > https://elixir.bootlin.com/linux/v4.18.5/source/fs/ocfs2/cluster/tcp.c#L2035 >> ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); Yes, I think that's the real bug here. Unless the socket is in fact exposed for direct use by userspace, it ought to be using sock_create_kern() or similar. I would suggest that you verify that the socket is never returned to userspace, and then submit a patch switching the code to using sock_create_kern(). > > >> On Sep 25, 2018, at 2:44 PM, Stephen Smalley <sds@tycho.nsa.gov> wrote: >> >> On 09/25/2018 01:27 PM, Tong Zhang wrote: >>> Kernel Version: 4.18.5 >>> Problem Description: >>> We found several leaking path or inconsistency LSM design issue in fs/net. >>> Currently we can only observe sock creation from kernel and all bind/listen/connect are not sent to LSM. >>> So, we think that those net/socket related stuff should all go through LSM check and being audited >>> even it is not a user thread or process. >>> Here?s an example where we have a check: >>> in fs/ocfs2/cluster/tcp.c:2035 o2net_open_listening_sock() a sock is created using sock_create(), >>> where a LSM check security_socket_create is called(net/socket.c:1242) >>> And where we don?t have a check >>> fs/ocfs2/cluster/tcp.c:2052 bind >>> fs/ocfs2/cluster/tcp.c:2059 listen >>> fs/dlm/lowcomms.c:1264 bind >>> fs/dlm/lowcomms.c:1278 listen >>> fs/dlm/lowcomms.c:1354 listen >>> several places that use kernel_bind/kernel_listen/kernel_connect >>> net/socket.c:3231 kernel_bind >>> net/socket.c:3237 kernel_listen >>> net/socket.c:3286 kernel_connect >> >> That's intentional. LSM isn't trying to mediate kernel-internal operations, and we do not want to apply permission checks against the credentials of the current userspace process for such operations. ocfs2 should likely be using sock_create_kern. >> > ^ permalink raw reply [flat|nested] 13+ messages in thread
* Leaking path or inconsistency LSM checking observed in fs/net @ 2018-09-26 13:09 ` Stephen Smalley 0 siblings, 0 replies; 13+ messages in thread From: Stephen Smalley @ 2018-09-26 13:09 UTC (permalink / raw) To: linux-security-module On 09/25/2018 07:36 PM, TongZhang wrote: > ocfs2 is using sock_create instead of sock_create_kern in kernel v4.18.5. > > fs/ocfs2/cluster/tcp.c: 1636 > https://elixir.bootlin.com/linux/v4.18.5/source/fs/ocfs2/cluster/tcp.c#L1636 >> ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); > > fs/ocfs2/cluster/tcp.c: 2035 > https://elixir.bootlin.com/linux/v4.18.5/source/fs/ocfs2/cluster/tcp.c#L2035 >> ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); Yes, I think that's the real bug here. Unless the socket is in fact exposed for direct use by userspace, it ought to be using sock_create_kern() or similar. I would suggest that you verify that the socket is never returned to userspace, and then submit a patch switching the code to using sock_create_kern(). > > >> On Sep 25, 2018, at 2:44 PM, Stephen Smalley <sds@tycho.nsa.gov> wrote: >> >> On 09/25/2018 01:27 PM, Tong Zhang wrote: >>> Kernel Version: 4.18.5 >>> Problem Description: >>> We found several leaking path or inconsistency LSM design issue in fs/net. >>> Currently we can only observe sock creation from kernel and all bind/listen/connect are not sent to LSM. >>> So, we think that those net/socket related stuff should all go through LSM check and being audited >>> even it is not a user thread or process. >>> Here?s an example where we have a check: >>> in fs/ocfs2/cluster/tcp.c:2035 o2net_open_listening_sock() a sock is created using sock_create(), >>> where a LSM check security_socket_create is called(net/socket.c:1242) >>> And where we don?t have a check >>> fs/ocfs2/cluster/tcp.c:2052 bind >>> fs/ocfs2/cluster/tcp.c:2059 listen >>> fs/dlm/lowcomms.c:1264 bind >>> fs/dlm/lowcomms.c:1278 listen >>> fs/dlm/lowcomms.c:1354 listen >>> several places that use kernel_bind/kernel_listen/kernel_connect >>> net/socket.c:3231 kernel_bind >>> net/socket.c:3237 kernel_listen >>> net/socket.c:3286 kernel_connect >> >> That's intentional. LSM isn't trying to mediate kernel-internal operations, and we do not want to apply permission checks against the credentials of the current userspace process for such operations. ocfs2 should likely be using sock_create_kern. >> > ^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2018-09-26 13:09 UTC | newest] Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2018-09-25 17:27 Leaking path or inconsistency LSM checking observed in fs/net Tong Zhang 2018-09-25 17:27 ` [Cluster-devel] " Tong Zhang 2018-09-25 17:27 ` Tong Zhang 2018-09-25 18:44 ` Stephen Smalley 2018-09-25 18:44 ` [Cluster-devel] " Stephen Smalley 2018-09-25 18:44 ` [Ocfs2-devel] " Stephen Smalley 2018-09-25 18:44 ` Stephen Smalley 2018-09-25 23:36 ` TongZhang 2018-09-25 23:36 ` [Cluster-devel] " TongZhang 2018-09-25 23:36 ` TongZhang 2018-09-26 13:09 ` Stephen Smalley 2018-09-26 13:09 ` [Cluster-devel] " Stephen Smalley 2018-09-26 13:09 ` Stephen Smalley
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