commit 897f1acbb6702ddaa953e8d8436eee3b12016c7e upstream. Add a space between subj= and feature= fields to make them parsable. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <pmoore@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9ef91514774a140e468f99d73d7593521e6d25dc upstream. When an AUDIT_GET_FEATURE message is sent from userspace to the kernel, it should reply with a message tagged as an AUDIT_GET_FEATURE type with a struct audit_feature. The current reply is a message tagged as an AUDIT_GET type with a struct audit_feature. This appears to have been a cut-and-paste-eo in commit b0fed40. Reported-by: Steve Grubb <sgrubb@redhat.com> Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7d8b6c63751cfbbe5eef81a48c22978b3407a3ad upstream. This is effectively a revert of 7b9a7ec565505699f503b4fcf61500dceb36e744 plus fixing it a different way... We found, when trying to run an application from an application which had dropped privs that the kernel does security checks on undefined capability bits. This was ESPECIALLY difficult to debug as those undefined bits are hidden from /proc/$PID/status. Consider a root application which drops all capabilities from ALL 4 capability sets. We assume, since the application is going to set eff/perm/inh from an array that it will clear not only the defined caps less than CAP_LAST_CAP, but also the higher 28ish bits which are undefined future capabilities. The BSET gets cleared differently. Instead it is cleared one bit at a time. The problem here is that in security/commoncap.c::cap_task_prctl() we actually check the validity of a capability being read. So any task which attempts to 'read all things set in bset' followed by 'unset all things set in bset' will not even attempt to unset the undefined bits higher than CAP_LAST_CAP. So the 'parent' will look something like: CapInh: 0000000000000000 CapPrm: 0000000000000000 CapEff: 0000000000000000 CapBnd: ffffffc000000000 All of this 'should' be fine. Given that these are undefined bits that aren't supposed to have anything to do with permissions. But they do... So lets now consider a task which cleared the eff/perm/inh completely and cleared all of the valid caps in the bset (but not the invalid caps it couldn't read out of the kernel). We know that this is exactly what the libcap-ng library does and what the go capabilities library does. They both leave you in that above situation if you try to clear all of you capapabilities from all 4 sets. If that root task calls execve() the child task will pick up all caps not blocked by the bset. The bset however does not block bits higher than CAP_LAST_CAP. So now the child task has bits in eff which are not in the parent. These are 'meaningless' undefined bits, but still bits which the parent doesn't have. The problem is now in cred_cap_issubset() (or any operation which does a subset test) as the child, while a subset for valid cap bits, is not a subset for invalid cap bits! So now we set durring commit creds that the child is not dumpable. Given it is 'more priv' than its parent. It also means the parent cannot ptrace the child and other stupidity. The solution here: 1) stop hiding capability bits in status This makes debugging easier! 2) stop giving any task undefined capability bits. it's simple, it you don't put those invalid bits in CAP_FULL_SET you won't get them in init and you won't get them in any other task either. This fixes the cap_issubset() tests and resulting fallout (which made the init task in a docker container untraceable among other things) 3) mask out undefined bits when sys_capset() is called as it might use ~0, ~0 to denote 'all capabilities' for backward/forward compatibility. This lets 'capsh --caps="all=eip" -- -c /bin/bash' run. 4) mask out undefined bit when we read a file capability off of disk as again likely all bits are set in the xattr for forward/backward compatibility. This lets 'setcap all+pe /bin/bash; /bin/bash' run Signed-off-by: Eric Paris <eparis@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Andrew Vagin <avagin@openvz.org> Cc: Andrew G. Morgan <morgan@kernel.org> Cc: Serge E. Hallyn <serge.hallyn@canonical.com> Cc: Kees Cook <keescook@chromium.org> Cc: Steve Grubb <sgrubb@redhat.com> Cc: Dan Walsh <dwalsh@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 90f62cf30a78721641e08737bda787552428061e ] It is possible by passing a netlink socket to a more privileged executable and then to fool that executable into writing to the socket data that happens to be valid netlink message to do something that privileged executable did not intend to do. To keep this from happening replace bare capable and ns_capable calls with netlink_capable, netlink_net_calls and netlink_ns_capable calls. Which act the same as the previous calls except they verify that the opener of the socket had the desired permissions as well. Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c92cdeb45eea38515e82187f48c2e4f435fb4e25 upstream. sys_getppid() returns the parent pid of the current process in its own pid namespace. Since audit filters are based in the init pid namespace, a process could avoid a filter or trigger an unintended one by being in an alternate pid namespace or log meaningless information. Switch to task_ppid_nr() for PPIDs to anchor all audit filters in the init_pid_ns. (informed by ebiederman's 6c621b7e) Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It its possible to configure your PAM stack to refuse login if audit messages (about the login) were unable to be sent. This is common in many distros and thus normal configuration of many containers. The PAM modules determine if audit is enabled/disabled in the kernel based on the return value from sending an audit message on the netlink socket. If userspace gets back ECONNREFUSED it believes audit is disabled in the kernel. If it gets any other error else it refuses to let the login proceed. Just about ever since the introduction of namespaces the kernel audit subsystem has returned EPERM if the task sending a message was not in the init user or pid namespace. So many forms of containers have never worked if audit was enabled in the kernel. BUT if the container was not in net_init then the kernel network code would send ECONNREFUSED (instead of the audit code sending EPERM). Thus by pure accident/dumb luck/bug if an admin configured the PAM stack to reject all logins that didn't talk to audit, but then ran the login untility in the non-init_net namespace, it would work!! Clearly this was a bug, but it is a bug some people expected. With the introduction of network namespace support in 3.14-rc1 the two bugs stopped cancelling each other out. Now, containers in the non-init_net namespace refused to let users log in (just like PAM was configfured!) Obviously some people were not happy that what used to let users log in, now didn't! This fix is kinda hacky. We return ECONNREFUSED for all non-init relevant namespaces. That means that not only will the old broken non-init_net setups continue to work, now the broken non-init_pid or non-init_user setups will 'work'. They don't really work, since audit isn't logging things. But it's what most users want. In 3.15 we should have patches to support not only the non-init_net (3.14) namespace but also the non-init_pid and non-init_user namespace. So all will be right in the world. This just opens the doors wide open on 3.14 and hopefully makes users happy, if not the audit system... Reported-by: Andre Tomt <andre@tomt.net> Reported-by: Adam Richter <adam_richter2004@yahoo.com> Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kbuild test robot reported: > tree: git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git for-next > head: 6f285b19d09f72e801525f5eea1bdad22e559bf0 > commit: 6f285b19d09f72e801525f5eea1bdad22e559bf0 [2/2] audit: Send replies in the proper network namespace. > reproduce: make htmldocs > > >> Warning(kernel/audit.c:575): No description found for parameter 'request_skb' > >> Warning(kernel/audit.c:575): Excess function parameter 'portid' description in 'audit_send_reply' > >> Warning(kernel/auditfilter.c:1074): No description found for parameter 'request_skb' > >> Warning(kernel/auditfilter.c:1074): Excess function parameter 'portid' description in 'audit_list_rules_s Which was caused by my failure to update the kdoc annotations when I updated the functions. Fix that small oversight now. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
In perverse cases of file descriptor passing the current network namespace of a process and the network namespace of a socket used by that socket may differ. Therefore use the network namespace of the appropiate socket to ensure replies always go to the appropiate socket. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
In struct audit_netlink_list and audit_reply add a reference to the network namespace of the caller and remove the userspace pid of the caller. This cleanly remembers the callers network namespace, and removes a huge class of races and nasty failure modes that can occur when attempting to relook up the callers network namespace from a pid_t (including the caller's network namespace changing, pid wraparound, and the pid simply not being present). Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Fixup caught by checkpatch. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com>