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path: root/security/smack/smack_lsm.c
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2019-01-08Smack: Abstract use of ipc security blobsCasey Schaufler
Don't use the ipc->security pointer directly. Don't use the msg_msg->security pointer directly. Provide helper functions that provides the security blob pointers. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08LSM: Infrastructure management of the inode securityCasey Schaufler
Move management of the inode->i_security blob out of the individual security modules and into the security infrastructure. Instead of allocating the blobs from within the modules the modules tell the infrastructure how much space is required, and the space is allocated there. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08Smack: Abstract use of inode security blobCasey Schaufler
Don't use the inode->i_security pointer directly. Provide a helper function that provides the security blob pointer. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08LSM: Infrastructure management of the file securityCasey Schaufler
Move management of the file->f_security blob out of the individual security modules and into the infrastructure. The modules no longer allocate or free the data, instead they tell the infrastructure how much space they require. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08Smack: Abstract use of file security blobCasey Schaufler
Don't use the file->f_security pointer directly. Provide a helper function that provides the security blob pointer. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08Infrastructure management of the cred security blobCasey Schaufler
Move management of the cred security blob out of the security modules and into the security infrastructre. Instead of allocating and freeing space the security modules tell the infrastructure how much space they require. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08Smack: Abstract use of cred security blobCasey Schaufler
Don't use the cred->security pointer directly. Provide a helper function that provides the security blob pointer. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08LSM: Separate idea of "major" LSM from "exclusive" LSMKees Cook
In order to both support old "security=" Legacy Major LSM selection, and handling real exclusivity, this creates LSM_FLAG_EXCLUSIVE and updates the selection logic to handle them. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
2019-01-08LSM: Lift LSM selection out of individual LSMsKees Cook
As a prerequisite to adjusting LSM selection logic in the future, this moves the selection logic up out of the individual major LSMs, making their init functions only run when actually enabled. This considers all LSMs enabled by default unless they specified an external "enable" variable. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com>
2019-01-08LSM: Introduce LSM_FLAG_LEGACY_MAJORKees Cook
This adds a flag for the current "major" LSMs to distinguish them when we have a universal method for ordering all LSMs. It's called "legacy" since the distinction of "major" will go away in the blob-sharing world. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com>
2019-01-05Merge branch 'mount.part1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs mount API prep from Al Viro: "Mount API prereqs. Mostly that's LSM mount options cleanups. There are several minor fixes in there, but nothing earth-shattering (leaks on failure exits, mostly)" * 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (27 commits) mount_fs: suppress MAC on MS_SUBMOUNT as well as MS_KERNMOUNT smack: rewrite smack_sb_eat_lsm_opts() smack: get rid of match_token() smack: take the guts of smack_parse_opts_str() into a new helper LSM: new method: ->sb_add_mnt_opt() selinux: rewrite selinux_sb_eat_lsm_opts() selinux: regularize Opt_... names a bit selinux: switch away from match_token() selinux: new helper - selinux_add_opt() LSM: bury struct security_mnt_opts smack: switch to private smack_mnt_opts selinux: switch to private struct selinux_mnt_opts LSM: hide struct security_mnt_opts from any generic code selinux: kill selinux_sb_get_mnt_opts() LSM: turn sb_eat_lsm_opts() into a method nfs_remount(): don't leak, don't ignore LSM options quietly btrfs: sanitize security_mnt_opts use selinux; don't open-code a loop in sb_finish_set_opts() LSM: split ->sb_set_mnt_opts() out of ->sb_kern_mount() new helper: security_sb_eat_lsm_opts() ...
2018-12-21smack: rewrite smack_sb_eat_lsm_opts()Al Viro
make it use smack_add_opt() and avoid separate copies - gather non-LSM options by memmove() in place Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21smack: get rid of match_token()Al Viro
same issue as with selinux... [fix by Andrei Vagin folded in] Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21smack: take the guts of smack_parse_opts_str() into a new helperAl Viro
smack_add_opt() adds an already matched option to growing smack_mnt_options Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21LSM: new method: ->sb_add_mnt_opt()Al Viro
Adding options to growing mnt_opts. NFS kludge with passing context= down into non-text-options mount switched to it, and with that the last use of ->sb_parse_opts_str() is gone. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21smack: switch to private smack_mnt_optsAl Viro
Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21LSM: hide struct security_mnt_opts from any generic codeAl Viro
Keep void * instead, allocate on demand (in parse_str_opts, at the moment). Eventually both selinux and smack will be better off with private structures with several strings in those, rather than this "counter and two pointers to dynamically allocated arrays" ugliness. This commit allows to do that at leisure, without disrupting anything outside of given module. Changes: * instead of struct security_mnt_opt use an opaque pointer initialized to NULL. * security_sb_eat_lsm_opts(), security_sb_parse_opts_str() and security_free_mnt_opts() take it as var argument (i.e. as void **); call sites are unchanged. * security_sb_set_mnt_opts() and security_sb_remount() take it by value (i.e. as void *). * new method: ->sb_free_mnt_opts(). Takes void *, does whatever freeing that needs to be done. * ->sb_set_mnt_opts() and ->sb_remount() might get NULL as mnt_opts argument, meaning "empty". Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21LSM: turn sb_eat_lsm_opts() into a methodAl Viro
Kill ->sb_copy_data() - it's used only in combination with immediately following ->sb_parse_opts_str(). Turn that combination into a new method. This is just a mechanical move - cleanups will be the next step. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21LSM: split ->sb_set_mnt_opts() out of ->sb_kern_mount()Al Viro
... leaving the "is it kernel-internal" logics in the caller. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21LSM: lift parsing LSM options into the caller of ->sb_kern_mount()Al Viro
This paves the way for retaining the LSM options from a common filesystem mount context during a mount parameter parsing phase to be instituted prior to actual mount/reconfiguration actions. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21smack: make smack_parse_opts_str() clean up on failureAl Viro
fixes e.g. a btrfs leak... Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-03smack: fix access permissions for keyringZoran Markovic
Function smack_key_permission() only issues smack requests for the following operations: - KEY_NEED_READ (issues MAY_READ) - KEY_NEED_WRITE (issues MAY_WRITE) - KEY_NEED_LINK (issues MAY_WRITE) - KEY_NEED_SETATTR (issues MAY_WRITE) A blank smack request is issued in all other cases, resulting in smack access being granted if there is any rule defined between subject and object, or denied with -EACCES otherwise. Request MAY_READ access for KEY_NEED_SEARCH and KEY_NEED_VIEW. Fix the logic in the unlikely case when both MAY_READ and MAY_WRITE are needed. Validate access permission field for valid contents. Signed-off-by: Zoran Markovic <zmarkovic@sierrawireless.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com>
2018-10-25Merge branch 'next-smack' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull smack updates from James Morris: "From Casey: three patches for Smack for 4.20. Two clean up warnings and one is a rarely encountered ptrace capability check" * 'next-smack' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: Smack: Mark expected switch fall-through Smack: ptrace capability use fixes Smack: remove set but not used variable 'root_inode'
2018-10-24Merge branch 'next-general' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "In this patchset, there are a couple of minor updates, as well as some reworking of the LSM initialization code from Kees Cook (these prepare the way for ordered stackable LSMs, but are a valuable cleanup on their own)" * 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: LSM: Don't ignore initialization failures LSM: Provide init debugging infrastructure LSM: Record LSM name in struct lsm_info LSM: Convert security_initcall() into DEFINE_LSM() vmlinux.lds.h: Move LSM_TABLE into INIT_DATA LSM: Convert from initcall to struct lsm_info LSM: Remove initcall tracing LSM: Rename .security_initcall section to .lsm_info vmlinux.lds.h: Avoid copy/paste of security_init section LSM: Correctly announce start of LSM initialization security: fix LSM description location keys: Fix the use of the C++ keyword "private" in uapi/linux/keyctl.h seccomp: remove unnecessary unlikely() security: tomoyo: Fix obsolete function security/capabilities: remove check for -EINVAL
2018-10-10LSM: Record LSM name in struct lsm_infoKees Cook
In preparation for making LSM selections outside of the LSMs, include the name of LSMs in struct lsm_info. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-10LSM: Convert security_initcall() into DEFINE_LSM()Kees Cook
Instead of using argument-based initializers, switch to defining the contents of struct lsm_info on a per-LSM basis. This also drops the final use of the now inaccurate "initcall" naming. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: James Morris <james.morris@microsoft.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-03signal: Distinguish between kernel_siginfo and siginfoEric W. Biederman
Linus recently observed that if we did not worry about the padding member in struct siginfo it is only about 48 bytes, and 48 bytes is much nicer than 128 bytes for allocating on the stack and copying around in the kernel. The obvious thing of only adding the padding when userspace is including siginfo.h won't work as there are sigframe definitions in the kernel that embed struct siginfo. So split siginfo in two; kernel_siginfo and siginfo. Keeping the traditional name for the userspace definition. While the version that is used internally to the kernel and ultimately will not be padded to 128 bytes is called kernel_siginfo. The definition of struct kernel_siginfo I have put in include/signal_types.h A set of buildtime checks has been added to verify the two structures have the same field offsets. To make it easy to verify the change kernel_siginfo retains the same size as siginfo. The reduction in size comes in a following change. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-09-18Smack: Mark expected switch fall-throughGustavo A. R. Silva
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Notice that in this particular case, I replaced "No break" with a proper "Fall through" annotation, which is what GCC is expecting to find. Warning level 2 was used: -Wimplicit-fallthrough=2 Addresses-Coverity-ID: 115051 ("Missing break in switch") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2018-09-18Smack: ptrace capability use fixesCasey Schaufler
This fixes a pair of problems in the Smack ptrace checks related to checking capabilities. In both cases, as reported by Lukasz Pawelczyk, the raw capability calls are used rather than the Smack wrapper that check addition restrictions. In one case, as reported by Jann Horn, the wrong task is being checked for capabilities. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2018-08-15Merge branch 'next-smack' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull smack updates from James Morris: "Minor fixes from Piotr Sawicki" * 'next-smack' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: Smack: Inform peer that IPv6 traffic has been blocked Smack: Check UDP-Lite and DCCP protocols during IPv6 handling Smack: Fix handling of IPv4 traffic received by PF_INET6 sockets
2018-08-13Merge branch 'work.open3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs open-related updates from Al Viro: - "do we need fput() or put_filp()" rules are gone - it's always fput() now. We keep track of that state where it belongs - in ->f_mode. - int *opened mess killed - in finish_open(), in ->atomic_open() instances and in fs/namei.c code around do_last()/lookup_open()/atomic_open(). - alloc_file() wrappers with saner calling conventions are introduced (alloc_file_clone() and alloc_file_pseudo()); callers converted, with much simplification. - while we are at it, saner calling conventions for path_init() and link_path_walk(), simplifying things inside fs/namei.c (both on open-related paths and elsewhere). * 'work.open3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits) few more cleanups of link_path_walk() callers allow link_path_walk() to take ERR_PTR() make path_init() unconditionally paired with terminate_walk() document alloc_file() changes make alloc_file() static do_shmat(): grab shp->shm_file earlier, switch to alloc_file_clone() new helper: alloc_file_clone() create_pipe_files(): switch the first allocation to alloc_file_pseudo() anon_inode_getfile(): switch to alloc_file_pseudo() hugetlb_file_setup(): switch to alloc_file_pseudo() ocxlflash_getfile(): switch to alloc_file_pseudo() cxl_getfile(): switch to alloc_file_pseudo() ... and switch shmem_file_setup() to alloc_file_pseudo() __shmem_file_setup(): reorder allocations new wrapper: alloc_file_pseudo() kill FILE_{CREATED,OPENED} switch atomic_open() and lookup_open() to returning 0 in all success cases document ->atomic_open() changes ->atomic_open(): return 0 in all success cases get rid of 'opened' in path_openat() and the helpers downstream ...
2018-07-23Smack: Inform peer that IPv6 traffic has been blockedPiotr Sawicki
In this patch we're sending an ICMPv6 message to a peer to immediately inform it that making a connection is not possible. In case of TCP connections, without this change, the peer will be waiting until a connection timeout is exceeded. Signed-off-by: Piotr Sawicki <p.sawicki2@partner.samsung.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2018-07-23Smack: Check UDP-Lite and DCCP protocols during IPv6 handlingPiotr Sawicki
The smack_socket_sock_rcv_skb() function is checking smack labels only for UDP and TCP frames carried in IPv6 packets. From now on, it is able also to handle UDP-Lite and DCCP protocols. Signed-off-by: Piotr Sawicki <p.sawicki2@partner.samsung.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2018-07-23Smack: Fix handling of IPv4 traffic received by PF_INET6 socketsPiotr Sawicki
A socket which has sk_family set to PF_INET6 is able to receive not only IPv6 but also IPv4 traffic (IPv4-mapped IPv6 addresses). Prior to this patch, the smk_skb_to_addr_ipv6() could have been called for socket buffers containing IPv4 packets, in result such traffic was allowed. Signed-off-by: Piotr Sawicki <p.sawicki2@partner.samsung.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2018-07-12->file_open(): lose cred argumentAl Viro
Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-06-23Smack: Mark inode instant in smack_task_to_inodeCasey Schaufler
Smack: Mark inode instant in smack_task_to_inode /proc clean-up in commit 1bbc55131e59bd099fdc568d3aa0b42634dbd188 resulted in smack_task_to_inode() being called before smack_d_instantiate. This resulted in the smk_inode value being ignored, even while present for files in /proc/self. Marking the inode as instant here fixes that. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2018-06-05Merge branch 'smack-for-4.18' of https://github.com/cschaufler/next-smack ↵James Morris
into next-smack "one simple patch that fixes a memory leak in kernfs and labeled NFS"
2018-06-05Smack: Fix memory leak in smack_inode_getsecctxCasey Schaufler
Fix memory leak in smack_inode_getsecctx The implementation of smack_inode_getsecctx() made incorrect assumptions about how Smack presents a security context. Smack does not need to allocate memory to support security contexts, so "releasing" a Smack context is a no-op. The code made an unnecessary copy and returned that as a context, which was never freed. The revised implementation returns the context correctly. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reported-by: CHANDAN VN <chandan.vn@samsung.com> Tested-by: CHANDAN VN <chandan.vn@samsung.com>
2018-05-04smack: provide socketpair callbackTom Gundersen
Make sure to implement the new socketpair callback so the SO_PEERSEC call on socketpair(2)s will return correct information. Signed-off-by: Tom Gundersen <teg@jklm.no> Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2018-04-11ipc/msg: introduce msgctl(MSG_STAT_ANY)Davidlohr Bueso
There is a permission discrepancy when consulting msq ipc object metadata between /proc/sysvipc/msg (0444) and the MSG_STAT shmctl command. The later does permission checks for the object vs S_IRUGO. As such there can be cases where EACCESS is returned via syscall but the info is displayed anyways in the procfs files. While this might have security implications via info leaking (albeit no writing to the msq metadata), this behavior goes way back and showing all the objects regardless of the permissions was most likely an overlook - so we are stuck with it. Furthermore, modifying either the syscall or the procfs file can cause userspace programs to break (ie ipcs). Some applications require getting the procfs info (without root privileges) and can be rather slow in comparison with a syscall -- up to 500x in some reported cases for shm. This patch introduces a new MSG_STAT_ANY command such that the msq ipc object permissions are ignored, and only audited instead. In addition, I've left the lsm security hook checks in place, as if some policy can block the call, then the user has no other choice than just parsing the procfs file. Link: http://lkml.kernel.org/r/20180215162458.10059-4-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reported-by: Robert Kettler <robert.kettler@outlook.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11ipc/sem: introduce semctl(SEM_STAT_ANY)Davidlohr Bueso
There is a permission discrepancy when consulting shm ipc object metadata between /proc/sysvipc/sem (0444) and the SEM_STAT semctl command. The later does permission checks for the object vs S_IRUGO. As such there can be cases where EACCESS is returned via syscall but the info is displayed anyways in the procfs files. While this might have security implications via info leaking (albeit no writing to the sma metadata), this behavior goes way back and showing all the objects regardless of the permissions was most likely an overlook - so we are stuck with it. Furthermore, modifying either the syscall or the procfs file can cause userspace programs to break (ie ipcs). Some applications require getting the procfs info (without root privileges) and can be rather slow in comparison with a syscall -- up to 500x in some reported cases for shm. This patch introduces a new SEM_STAT_ANY command such that the sem ipc object permissions are ignored, and only audited instead. In addition, I've left the lsm security hook checks in place, as if some policy can block the call, then the user has no other choice than just parsing the procfs file. Link: http://lkml.kernel.org/r/20180215162458.10059-3-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reported-by: Robert Kettler <robert.kettler@outlook.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11ipc/shm: introduce shmctl(SHM_STAT_ANY)Davidlohr Bueso
Patch series "sysvipc: introduce STAT_ANY commands", v2. The following patches adds the discussed (see [1]) new command for shm as well as for sems and msq as they are subject to the same discrepancies for ipc object permission checks between the syscall and via procfs. These new commands are justified in that (1) we are stuck with this semantics as changing syscall and procfs can break userland; and (2) some users can benefit from performance (for large amounts of shm segments, for example) from not having to parse the procfs interface. Once merged, I will submit the necesary manpage updates. But I'm thinking something like: : diff --git a/man2/shmctl.2 b/man2/shmctl.2 : index 7bb503999941..bb00bbe21a57 100644 : --- a/man2/shmctl.2 : +++ b/man2/shmctl.2 : @@ -41,6 +41,7 @@ : .\" 2005-04-25, mtk -- noted aberrant Linux behavior w.r.t. new : .\" attaches to a segment that has already been marked for deletion. : .\" 2005-08-02, mtk: Added IPC_INFO, SHM_INFO, SHM_STAT descriptions. : +.\" 2018-02-13, dbueso: Added SHM_STAT_ANY description. : .\" : .TH SHMCTL 2 2017-09-15 "Linux" "Linux Programmer's Manual" : .SH NAME : @@ -242,6 +243,18 @@ However, the : argument is not a segment identifier, but instead an index into : the kernel's internal array that maintains information about : all shared memory segments on the system. : +.TP : +.BR SHM_STAT_ANY " (Linux-specific)" : +Return a : +.I shmid_ds : +structure as for : +.BR SHM_STAT . : +However, the : +.I shm_perm.mode : +is not checked for read access for : +.IR shmid , : +resembing the behaviour of : +/proc/sysvipc/shm. : .PP : The caller can prevent or allow swapping of a shared : memory segment with the following \fIcmd\fP values: : @@ -287,7 +300,7 @@ operation returns the index of the highest used entry in the : kernel's internal array recording information about all : shared memory segments. : (This information can be used with repeated : -.B SHM_STAT : +.B SHM_STAT/SHM_STAT_ANY : operations to obtain information about all shared memory segments : on the system.) : A successful : @@ -328,7 +341,7 @@ isn't accessible. : \fIshmid\fP is not a valid identifier, or \fIcmd\fP : is not a valid command. : Or: for a : -.B SHM_STAT : +.B SHM_STAT/SHM_STAT_ANY : operation, the index value specified in : .I shmid : referred to an array slot that is currently unused. This patch (of 3): There is a permission discrepancy when consulting shm ipc object metadata between /proc/sysvipc/shm (0444) and the SHM_STAT shmctl command. The later does permission checks for the object vs S_IRUGO. As such there can be cases where EACCESS is returned via syscall but the info is displayed anyways in the procfs files. While this might have security implications via info leaking (albeit no writing to the shm metadata), this behavior goes way back and showing all the objects regardless of the permissions was most likely an overlook - so we are stuck with it. Furthermore, modifying either the syscall or the procfs file can cause userspace programs to break (ie ipcs). Some applications require getting the procfs info (without root privileges) and can be rather slow in comparison with a syscall -- up to 500x in some reported cases. This patch introduces a new SHM_STAT_ANY command such that the shm ipc object permissions are ignored, and only audited instead. In addition, I've left the lsm security hook checks in place, as if some policy can block the call, then the user has no other choice than just parsing the procfs file. [1] https://lkml.org/lkml/2017/12/19/220 Link: http://lkml.kernel.org/r/20180215162458.10059-2-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Cc: Robert Kettler <robert.kettler@outlook.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-07Merge branch 'next-integrity' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull integrity updates from James Morris: "A mixture of bug fixes, code cleanup, and continues to close IMA-measurement, IMA-appraisal, and IMA-audit gaps. Also note the addition of a new cred_getsecid LSM hook by Matthew Garrett: For IMA purposes, we want to be able to obtain the prepared secid in the bprm structure before the credentials are committed. Add a cred_getsecid hook that makes this possible. which is used by a new CREDS_CHECK target in IMA: In ima_bprm_check(), check with both the existing process credentials and the credentials that will be committed when the new process is started. This will not change behaviour unless the system policy is extended to include CREDS_CHECK targets - BPRM_CHECK will continue to check the same credentials that it did previously" * 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: ima: Fallback to the builtin hash algorithm ima: Add smackfs to the default appraise/measure list evm: check for remount ro in progress before writing ima: Improvements in ima_appraise_measurement() ima: Simplify ima_eventsig_init() integrity: Remove unused macro IMA_ACTION_RULE_FLAGS ima: drop vla in ima_audit_measurement() ima: Fix Kconfig to select TPM 2.0 CRB interface evm: Constify *integrity_status_msg[] evm: Move evm_hmac and evm_hash from evm_main.c to evm_crypto.c fuse: define the filesystem as untrusted ima: fail signature verification based on policy ima: clear IMA_HASH ima: re-evaluate files on privileged mounted filesystems ima: fail file signature verification on non-init mounted filesystems IMA: Support using new creds in appraisal policy security: Add a cred_getsecid hook
2018-04-07Merge branch 'next-smack' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull smack update from James Morris: "One small change for Automotive Grade Linux" * 'next-smack' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: Smack: Handle CGROUP2 in the same way that CGROUP
2018-04-07Merge branch 'next-general' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull general security layer updates from James Morris: - Convert security hooks from list to hlist, a nice cleanup, saving about 50% of space, from Sargun Dhillon. - Only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill (as the secid can be determined from the cred), from Stephen Smalley. - Close a potential race in kernel_read_file(), by making the file unwritable before calling the LSM check (vs after), from Kees Cook. * 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: security: convert security hooks to use hlist exec: Set file unwritable before LSM check usb, signal, security: only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill
2018-03-27ipc/smack: Tidy up from the change in type of the ipc security hooksEric W. Biederman
Rename the variables shp, sma, msq to isp. As that is how the code already refers to those variables. Collapse smack_of_shm, smack_of_sem, and smack_of_msq into smack_of_ipc, as the three functions had become completely identical. Collapse smack_shm_alloc_security, smack_sem_alloc_security and smack_msg_queue_alloc_security into smack_ipc_alloc_security as the three functions had become identical. Collapse smack_shm_free_security, smack_sem_free_security and smack_msg_queue_free_security into smack_ipc_free_security as the three functions had become identical. Requested-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-03-27Merge branch 'smack-for-4.17' of git://github.com/cschaufler/next-smack into ↵James Morris
next-smack Pull request from Casey.
2018-03-23security: Add a cred_getsecid hookMatthew Garrett
For IMA purposes, we want to be able to obtain the prepared secid in the bprm structure before the credentials are committed. Add a cred_getsecid hook that makes this possible. Signed-off-by: Matthew Garrett <mjg59@google.com> Acked-by: Paul Moore <paul@paul-moore.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-22msg/security: Pass kern_ipc_perm not msg_queue into the msg_queue security hooksEric W. Biederman
All of the implementations of security hooks that take msg_queue only access q_perm the struct kern_ipc_perm member. This means the dependencies of the msg_queue security hooks can be simplified by passing the kern_ipc_perm member of msg_queue. Making this change will allow struct msg_queue to become private to ipc/msg.c. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-03-22shm/security: Pass kern_ipc_perm not shmid_kernel into the shm security hooksEric W. Biederman
All of the implementations of security hooks that take shmid_kernel only access shm_perm the struct kern_ipc_perm member. This means the dependencies of the shm security hooks can be simplified by passing the kern_ipc_perm member of shmid_kernel.. Making this change will allow struct shmid_kernel to become private to ipc/shm.c. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>