summaryrefslogtreecommitdiffstats
path: root/security
AgeCommit message (Collapse)AuthorFilesLines
2016-07-20qstr: constify dentry_init_securityAl Viro2-2/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-12apparmor: fix arg_size computation for when setprocattr is null terminatedJohn Johansen1-1/+1
Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12apparmor: fix oops, validate buffer size in apparmor_setprocattr()Vegard Nossum1-17/+19
When proc_pid_attr_write() was changed to use memdup_user apparmor's (interface violating) assumption that the setprocattr buffer was always a single page was violated. The size test is not strictly speaking needed as proc_pid_attr_write() will reject anything larger, but for the sake of robustness we can keep it in. SMACK and SELinux look safe to me, but somebody else should probably have a look just in case. Based on original patch from Vegard Nossum <vegard.nossum@oracle.com> modified for the case that apparmor provides null termination. Fixes: bb646cdb12e75d82258c2f2e7746d5952d3e321a Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: John Johansen <john.johansen@canonical.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Eric Paris <eparis@parisplace.org> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: stable@kernel.org Signed-off-by: John Johansen <john.johansen@canonical.com> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-07-12apparmor: do not expose kernel stackHeinrich Schuchardt1-1/+3
Do not copy uninitalized fields th.td_hilen, th.td_data. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12apparmor: fix module parameters can be changed after policy is lockedJohn Johansen3-13/+29
the policy_lock parameter is a one way switch that prevents policy from being further modified. Unfortunately some of the module parameters can effectively modify policy by turning off enforcement. split policy_admin_capable into a view check and a full admin check, and update the admin check to test the policy_lock parameter. Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12apparmor: fix oops in profile_unpack() when policy_db is not presentJohn Johansen1-0/+3
BugLink: http://bugs.launchpad.net/bugs/1592547 If unpack_dfa() returns NULL due to the dfa not being present, profile_unpack() is not checking if the dfa is not present (NULL). Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12apparmor: don't check for vmalloc_addr if kvzalloc() failedJohn Johansen1-5/+5
Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12apparmor: add missing id bounds check on dfa verificationJohn Johansen2-0/+3
Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12apparmor: allow SYS_CAP_RESOURCE to be sufficient to prlimit another taskJeff Mahoney1-2/+4
While using AppArmor, SYS_CAP_RESOURCE is insufficient to call prlimit on another task. The only other example of a AppArmor mediating access to another, already running, task (ignoring fork+exec) is ptrace. The AppArmor model for ptrace is that one of the following must be true: 1) The tracer is unconfined 2) The tracer is in complain mode 3) The tracer and tracee are confined by the same profile 4) The tracer is confined but has SYS_CAP_PTRACE 1), 2, and 3) are already true for setrlimit. We can match the ptrace model just by allowing CAP_SYS_RESOURCE. We still test the values of the rlimit since it can always be overridden using a value that means unlimited for a particular resource. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12apparmor: use list_next_entry instead of list_entry_nextGeliang Tang1-5/+3
list_next_entry has been defined in list.h, so I replace list_entry_next with it. Signed-off-by: Geliang Tang <geliangtang@163.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12apparmor: fix refcount race when finding a child profileJohn Johansen1-1/+3
When finding a child profile via an rcu critical section, the profile may be put and scheduled for deletion after the child is found but before its refcount is incremented. Protect against this by repeating the lookup if the profiles refcount is 0 and is one its way to deletion. Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12apparmor: fix ref count leak when profile sha1 hash is readJohn Johansen1-0/+1
Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12apparmor: check that xindex is in trans_table boundsJohn Johansen1-1/+1
Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12apparmor: ensure the target profile name is always auditedJohn Johansen1-11/+9
The target profile name was not being correctly audited in a few cases because the target variable was not being set and gotos passed the code to set it at apply: Since it is always based on new_profile just drop the target var and conditionally report based on new_profile. Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12apparmor: fix audit full profile hname on successful loadJohn Johansen1-1/+1
Currently logging of a successful profile load only logs the basename of the profile. This can result in confusion when a child profile has the same name as the another profile in the set. Logging the hname will ensure there is no confusion. Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12apparmor: fix log failures for all profiles in a setJohn Johansen1-10/+19
currently only the profile that is causing the failure is logged. This makes it more confusing than necessary about which profiles loaded and which didn't. So make sure to log success and failure messages for all profiles in the set being loaded. Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12apparmor: fix put() parent ref after updating the active refJohn Johansen1-1/+1
Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12apparmor: add parameter to control whether policy hashing is usedJohn Johansen4-6/+25
Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Tyler Hicks <tyhicks@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12apparmor: internal paths should be treated as disconnectedJohn Johansen1-28/+36
Internal mounts are not mounted anywhere and as such should be treated as disconnected paths. Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12apparmor: fix disconnected bind mnts reconnectionJohn Johansen1-1/+4
Bind mounts can fail to be properly reconnected when PATH_CONNECT is specified. Ensure that when PATH_CONNECT is specified the path has a root. BugLink: http://bugs.launchpad.net/bugs/1319984 Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12apparmor: fix update the mtime of the profile file on replacementJohn Johansen1-0/+2
Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12apparmor: exec should not be returning ENOENT when it deniesJohn Johansen1-1/+1
The current behavior is confusing as it causes exec failures to report the executable is missing instead of identifying that apparmor caused the failure. Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12apparmor: fix uninitialized lsm_audit memberJohn Johansen2-2/+4
BugLink: http://bugs.launchpad.net/bugs/1268727 The task field in the lsm_audit struct needs to be initialized if a change_hat fails, otherwise the following oops will occur BUG: unable to handle kernel paging request at 0000002fbead7d08 IP: [<ffffffff8171153e>] _raw_spin_lock+0xe/0x50 PGD 1e3f35067 PUD 0 Oops: 0002 [#1] SMP Modules linked in: pppox crc_ccitt p8023 p8022 psnap llc ax25 btrfs raid6_pq xor xfs libcrc32c dm_multipath scsi_dh kvm_amd dcdbas kvm microcode amd64_edac_mod joydev edac_core psmouse edac_mce_amd serio_raw k10temp sp5100_tco i2c_piix4 ipmi_si ipmi_msghandler acpi_power_meter mac_hid lp parport hid_generic usbhid hid pata_acpi mpt2sas ahci raid_class pata_atiixp bnx2 libahci scsi_transport_sas [last unloaded: tipc] CPU: 2 PID: 699 Comm: changehat_twice Tainted: GF O 3.13.0-7-generic #25-Ubuntu Hardware name: Dell Inc. PowerEdge R415/08WNM9, BIOS 1.8.6 12/06/2011 task: ffff8802135c6000 ti: ffff880212986000 task.ti: ffff880212986000 RIP: 0010:[<ffffffff8171153e>] [<ffffffff8171153e>] _raw_spin_lock+0xe/0x50 RSP: 0018:ffff880212987b68 EFLAGS: 00010006 RAX: 0000000000020000 RBX: 0000002fbead7500 RCX: 0000000000000000 RDX: 0000000000000292 RSI: ffff880212987ba8 RDI: 0000002fbead7d08 RBP: ffff880212987b68 R08: 0000000000000246 R09: ffff880216e572a0 R10: ffffffff815fd677 R11: ffffea0008469580 R12: ffffffff8130966f R13: ffff880212987ba8 R14: 0000002fbead7d08 R15: ffff8800d8c6b830 FS: 00002b5e6c84e7c0(0000) GS:ffff880216e40000(0000) knlGS:0000000055731700 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000002fbead7d08 CR3: 000000021270f000 CR4: 00000000000006e0 Stack: ffff880212987b98 ffffffff81075f17 ffffffff8130966f 0000000000000009 0000000000000000 0000000000000000 ffff880212987bd0 ffffffff81075f7c 0000000000000292 ffff880212987c08 ffff8800d8c6b800 0000000000000026 Call Trace: [<ffffffff81075f17>] __lock_task_sighand+0x47/0x80 [<ffffffff8130966f>] ? apparmor_cred_prepare+0x2f/0x50 [<ffffffff81075f7c>] do_send_sig_info+0x2c/0x80 [<ffffffff81075fee>] send_sig_info+0x1e/0x30 [<ffffffff8130242d>] aa_audit+0x13d/0x190 [<ffffffff8130c1dc>] aa_audit_file+0xbc/0x130 [<ffffffff8130966f>] ? apparmor_cred_prepare+0x2f/0x50 [<ffffffff81304cc2>] aa_change_hat+0x202/0x530 [<ffffffff81308fc6>] aa_setprocattr_changehat+0x116/0x1d0 [<ffffffff8130a11d>] apparmor_setprocattr+0x25d/0x300 [<ffffffff812cee56>] security_setprocattr+0x16/0x20 [<ffffffff8121fc87>] proc_pid_attr_write+0x107/0x130 [<ffffffff811b7604>] vfs_write+0xb4/0x1f0 [<ffffffff811b8039>] SyS_write+0x49/0xa0 [<ffffffff8171a1bf>] tracesys+0xe1/0xe6 Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12apparmor: fix replacement bug that adds new child to old parentJohn Johansen1-1/+1
When set atomic replacement is used and the parent is updated before the child, and the child did not exist in the old parent so there is no direct replacement then the new child is incorrectly added to the old parent. This results in the new parent not having the child(ren) that it should and the old parent when being destroyed asserting the following error. AppArmor: policy_destroy: internal error, policy '<profile/name>' still contains profiles Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12apparmor: fix refcount bug in profile replacementJohn Johansen1-2/+2
Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-09Merge tag 'keys-misc-20160708' of ↵James Morris2-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into next
2016-07-08Merge branch 'smack-for-4.8' of https://github.com/cschaufler/smack-next ↵James Morris1-0/+3
into next
2016-07-08apparmor: fix oops, validate buffer size in apparmor_setprocattr()Vegard Nossum1-17/+19
When proc_pid_attr_write() was changed to use memdup_user apparmor's (interface violating) assumption that the setprocattr buffer was always a single page was violated. The size test is not strictly speaking needed as proc_pid_attr_write() will reject anything larger, but for the sake of robustness we can keep it in. SMACK and SELinux look safe to me, but somebody else should probably have a look just in case. Based on original patch from Vegard Nossum <vegard.nossum@oracle.com> modified for the case that apparmor provides null termination. Fixes: bb646cdb12e75d82258c2f2e7746d5952d3e321a Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: John Johansen <john.johansen@canonical.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Eric Paris <eparis@parisplace.org> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: stable@kernel.org Signed-off-by: John Johansen <john.johansen@canonical.com> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-07-07Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/selinux ↵James Morris7-64/+73
into next
2016-07-05evm: Translate user/group ids relative to s_user_ns when computing HMACSeth Forshee1-2/+2
The EVM HMAC should be calculated using the on disk user and group ids, so the k[ug]ids in the inode must be translated relative to the s_user_ns of the inode's super block. Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-06-30Merge branch 'd_real' of ↵Al Viro5-7/+14
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs into work.misc
2016-06-30ima: extend the measurement entry specific pcrEric Richter1-3/+3
Extend the PCR supplied as a parameter, instead of assuming that the measurement entry uses the default configured PCR. Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30ima: change integrity cache to store measured pcrEric Richter3-3/+11
IMA avoids re-measuring files by storing the current state as a flag in the integrity cache. It will then skip adding a new measurement log entry if the cache reports the file as already measured. If a policy measures an already measured file to a new PCR, the measurement will not be added to the list. This patch implements a new bitfield for specifying which PCR the file was measured into, rather than if it was measured. Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30ima: redefine duplicate template entriesEric Richter1-3/+4
Template entry duplicates are prevented from being added to the measurement list by checking a hash table that contains the template entry digests. However, the PCR value is not included in this comparison, so duplicate template entry digests with differing PCRs may be dropped. This patch redefines duplicate template entries as template entries with the same digest and same PCR values. Reported-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30ima: change ima_measurements_show() to display the entry specific pcrEric Richter1-5/+4
IMA assumes that the same default Kconfig PCR is extended for each entry. This patch replaces the default configured PCR with the policy defined PCR. Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30ima: include pcr for each measurement log entryEric Richter4-8/+13
The IMA measurement list entries include the Kconfig defined PCR value. This patch defines a new ima_template_entry field for including the PCR as specified in the policy rule. Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30ima: extend ima_get_action() to return the policy pcrEric Richter5-7/+14
Different policy rules may extend different PCRs. This patch retrieves the specific PCR for the matched rule. Subsequent patches will include the rule specific PCR in the measurement list and extend the appropriate PCR. Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30ima: add policy support for extending different pcrsEric Richter1-1/+28
This patch defines a new IMA measurement policy rule option "pcr=", which allows extending different PCRs on a per rule basis. For example, the system independent files could extend the default IMA Kconfig specified PCR, while the system dependent files could extend a different PCR. The following is an example of this usage with an SELinux policy; the rule would extend PCR 11 with system configuration files: measure func=FILE_CHECK mask=MAY_READ obj_type=system_conf_t pcr=11 Changelog v3: - FIELD_SIZEOF returns bytes, not bits. Fixed INVALID_PCR Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30integrity: add measured_pcrs field to integrity cacheEric Richter2-0/+3
To keep track of which measurements have been extended to which PCRs, this patch defines a new integrity_iint_cache field named measured_pcrs. This field is a bitmask of the PCRs measured. Each bit corresponds to a PCR index. For example, bit 10 corresponds to PCR 10. Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-27calipso: Add a label cache.Huw Davies1-3/+6
This works in exactly the same way as the CIPSO label cache. The idea is to allow the lsm to cache the result of a secattr lookup so that it doesn't need to perform the lookup for every skbuff. It introduces two sysctl controls: calipso_cache_enable - enables/disables the cache. calipso_cache_bucket_size - sets the size of a cache bucket. Signed-off-by: Huw Davies <huw@codeweavers.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-27netlabel: Pass a family parameter to netlbl_skbuff_err().Huw Davies4-8/+10
This makes it possible to route the error to the appropriate labelling engine. CALIPSO is far less verbose than CIPSO when encountering a bogus packet, so there is no need for a CALIPSO error handler. Signed-off-by: Huw Davies <huw@codeweavers.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-27calipso: Allow the lsm to label the skbuff directly.Huw Davies1-0/+15
In some cases, the lsm needs to add the label to the skbuff directly. A NF_INET_LOCAL_OUT IPv6 hook is added to selinux to match the IPv4 behaviour. This allows selinux to label the skbuffs that it requires. Signed-off-by: Huw Davies <huw@codeweavers.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-27calipso: Allow request sockets to be relabelled by the lsm.Huw Davies1-1/+1
Request sockets need to have a label that takes into account the incoming connection as well as their parent's label. This is used for the outgoing SYN-ACK and for their child full-socket. Signed-off-by: Huw Davies <huw@codeweavers.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-27netlabel: Prevent setsockopt() from changing the hop-by-hop option.Huw Davies1-1/+16
If a socket has a netlabel in place then don't let setsockopt() alter the socket's IPv6 hop-by-hop option. This is in the same spirit as the existing check for IPv4. Signed-off-by: Huw Davies <huw@codeweavers.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-27calipso: Set the calipso socket label to match the secattr.Huw Davies1-1/+1
CALIPSO is a hop-by-hop IPv6 option. A lot of this patch is based on the equivalent CISPO code. The main difference is due to manipulating the options in the hop-by-hop header. Signed-off-by: Huw Davies <huw@codeweavers.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-24selinux: Add support for unprivileged mounts from user namespacesSeth Forshee1-0/+23
Security labels from unprivileged mounts in user namespaces must be ignored. Force superblocks from user namespaces whose labeling behavior is to use xattrs to use mountpoint labeling instead. For the mountpoint label, default to converting the current task context into a form suitable for file objects, but also allow the policy writer to specify a different label through policy transition rules. Pieced together from code snippets provided by Stephen Smalley. Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-06-24Smack: Handle labels consistently in untrusted mountsSeth Forshee1-10/+19
The SMACK64, SMACK64EXEC, and SMACK64MMAP labels are all handled differently in untrusted mounts. This is confusing and potentically problematic. Change this to handle them all the same way that SMACK64 is currently handled; that is, read the label from disk and check it at use time. For SMACK64 and SMACK64MMAP access is denied if the label does not match smk_root. To be consistent with suid, a SMACK64EXEC label which does not match smk_root will still allow execution of the file but will not run with the label supplied in the xattr. Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-06-24Smack: Add support for unprivileged mounts from user namespacesSeth Forshee2-12/+37
Security labels from unprivileged mounts cannot be trusted. Ideally for these mounts we would assign the objects in the filesystem the same label as the inode for the backing device passed to mount. Unfortunately it's currently impossible to determine which inode this is from the LSM mount hooks, so we settle for the label of the process doing the mount. This label is assigned to s_root, and also to smk_default to ensure that new inodes receive this label. The transmute property is also set on s_root to make this behavior more explicit, even though it is technically not necessary. If a filesystem has existing security labels, access to inodes is permitted if the label is the same as smk_root, otherwise access is denied. The SMACK64EXEC xattr is completely ignored. Explicit setting of security labels continues to require CAP_MAC_ADMIN in init_user_ns. Altogether, this ensures that filesystem objects are not accessible to subjects which cannot already access the backing store, that MAC is not violated for any objects in the fileystem which are already labeled, and that a user cannot use an unprivileged mount to gain elevated MAC privileges. sysfs, tmpfs, and ramfs are already mountable from user namespaces and support security labels. We can't rule out the possibility that these filesystems may already be used in mounts from user namespaces with security lables set from the init namespace, so failing to trust lables in these filesystems may introduce regressions. It is safe to trust labels from these filesystems, since the unprivileged user does not control the backing store and thus cannot supply security labels, so an explicit exception is made to trust labels from these filesystems. Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-06-24fs: Treat foreign mounts as nosuidAndy Lutomirski2-2/+8
If a process gets access to a mount from a different user namespace, that process should not be able to take advantage of setuid files or selinux entrypoints from that filesystem. Prevent this by treating mounts from other mount namespaces and those not owned by current_user_ns() or an ancestor as nosuid. This will make it safer to allow more complex filesystems to be mounted in non-root user namespaces. This does not remove the need for MNT_LOCK_NOSUID. The setuid, setgid, and file capability bits can no longer be abused if code in a user namespace were to clear nosuid on an untrusted filesystem, but this patch, by itself, is insufficient to protect the system from abuse of files that, when execed, would increase MAC privilege. As a more concrete explanation, any task that can manipulate a vfsmount associated with a given user namespace already has capabilities in that namespace and all of its descendents. If they can cause a malicious setuid, setgid, or file-caps executable to appear in that mount, then that executable will only allow them to elevate privileges in exactly the set of namespaces in which they are already privileges. On the other hand, if they can cause a malicious executable to appear with a dangerous MAC label, running it could change the caller's security context in a way that should not have been possible, even inside the namespace in which the task is confined. As a hardening measure, this would have made CVE-2014-5207 much more difficult to exploit. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Acked-by: James Morris <james.l.morris@oracle.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-06-24fs: Limit file caps to the user namespace of the super blockSeth Forshee1-0/+2
Capability sets attached to files must be ignored except in the user namespaces where the mounter is privileged, i.e. s_user_ns and its descendants. Otherwise a vector exists for gaining privileges in namespaces where a user is not already privileged. Add a new helper function, current_in_user_ns(), to test whether a user namespace is the same as or a descendant of another namespace. Use this helper to determine whether a file's capability set should be applied to the caps constructed during exec. --EWB Replaced in_userns with the simpler current_in_userns. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-20 05:11:08 +0000