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path: root/security/selinux/ss/mls.h
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2018-12-05selinux: overhaul sidtab to fix bug and improve performanceOndrej Mosnacek
Before this patch, during a policy reload the sidtab would become frozen and trying to map a new context to SID would be unable to add a new entry to sidtab and fail with -ENOMEM. Such failures are usually propagated into userspace, which has no way of distignuishing them from actual allocation failures and thus doesn't handle them gracefully. Such situation can be triggered e.g. by the following reproducer: while true; do load_policy; echo -n .; sleep 0.1; done & for (( i = 0; i < 1024; i++ )); do runcon -l s0:c$i echo -n x || break # or: # chcon -l s0:c$i <some_file> || break done This patch overhauls the sidtab so it doesn't need to be frozen during policy reload, thus solving the above problem. The new SID table leverages the fact that SIDs are allocated sequentially and are never invalidated and stores them in linear buckets indexed by a tree structure. This brings several advantages: 1. Fast SID -> context lookup - this lookup can now be done in logarithmic time complexity (usually in less than 4 array lookups) and can still be done safely without locking. 2. No need to re-search the whole table on reverse lookup miss - after acquiring the spinlock only the newly added entries need to be searched, which means that reverse lookups that end up inserting a new entry are now about twice as fast. 3. No need to freeze sidtab during policy reload - it is now possible to handle insertion of new entries even during sidtab conversion. The tree structure of the new sidtab is able to grow automatically to up to about 2^31 entries (at which point it should not have more than about 4 tree levels). The old sidtab had a theoretical capacity of almost 2^32 entries, but half of that is still more than enough since by that point the reverse table lookups would become unusably slow anyway... The number of entries per tree node is selected automatically so that each node fits into a single page, which should be the easiest size for kmalloc() to handle. Note that the cache for reverse lookup is preserved with equivalent logic. The only difference is that instead of storing pointers to the hash table nodes it stores just the indices of the cached entries. The new cache ensures that the indices are loaded/stored atomically, but it still has the drawback that concurrent cache updates may mess up the contents of the cache. Such situation however only reduces its effectivity, not the correctness of lookups. Tested by selinux-testsuite and thoroughly tortured by this simple stress test: ``` function rand_cat() { echo $(( $RANDOM % 1024 )) } function do_work() { while true; do echo -n "system_u:system_r:kernel_t:s0:c$(rand_cat),c$(rand_cat)" \ >/sys/fs/selinux/context 2>/dev/null || true done } do_work >/dev/null & do_work >/dev/null & do_work >/dev/null & while load_policy; do echo -n .; sleep 0.1; done kill %1 kill %2 kill %3 ``` Link: https://github.com/SELinuxProject/selinux-kernel/issues/38 Reported-by: Orion Poplawski <orion@nwra.com> Reported-by: Li Kun <hw.likun@huawei.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: most of sidtab.c merged by hand due to conflicts] [PM: checkpatch fixes in mls.c, services.c, sidtab.c] Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-09-05selinux: refactor mls_context_to_sid() and make it stricterJann Horn
The intended behavior change for this patch is to reject any MLS strings that contain (trailing) garbage if p->mls_enabled is true. As suggested by Paul Moore, change mls_context_to_sid() so that the two parts of the range are extracted before the rest of the parsing. Because now we don't have to scan for two different separators simultaneously everywhere, we can actually switch to strchr() everywhere instead of the open-coded loops that scan for two separators at once. mls_context_to_sid() used to signal how much of the input string was parsed by updating `*scontext`. However, there is actually no case in which mls_context_to_sid() only parses a subset of the input and still returns a success (other than the buggy case with a second '-' in which it incorrectly claims to have consumed the entire string). Turn `scontext` into a simple pointer argument and stop redundantly checking whether the entire input was consumed in string_to_context_struct(). This also lets us remove the `scontext_len` argument from `string_to_context_struct()`. Signed-off-by: Jann Horn <jannh@google.com> [PM: minor merge fuzz in convert_context()] Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-03-01selinux: wrap global selinux stateStephen Smalley
Define a selinux state structure (struct selinux_state) for global SELinux state and pass it explicitly to all security server functions. The public portion of the structure contains state that is used throughout the SELinux code, such as the enforcing mode. The structure also contains a pointer to a selinux_ss structure whose definition is private to the security server and contains security server specific state such as the policy database and SID table. This change should have no effect on SELinux behavior or APIs (userspace or LSM). It merely wraps SELinux state and passes it explicitly as needed. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: minor fixups needed due to collisions with the SCTP patches] Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-17selinux: update my email addressStephen Smalley
Update my email address since epoch.ncsc.mil no longer exists. MAINTAINERS and CREDITS are already correct. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2011-08-01doc: Update the email address for Paul Moore in various source filesPaul Moore
My @hp.com will no longer be valid starting August 5, 2011 so an update is necessary. My new email address is employer independent so we don't have to worry about doing this again any time soon. Signed-off-by: Paul Moore <paul.moore@hp.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-03SELinux: Socket retains creator role and MLS attributeHarry Ciao
The socket SID would be computed on creation and no longer inherit its creator's SID by default. Socket may have a different type but needs to retain the creator's role and MLS attribute in order not to break labeled networking and network access control. The kernel value for a class would be used to determine if the class if one of socket classes. If security_compute_sid is called from userspace the policy value for a class would be mapped to the relevant kernel value first. Signed-off-by: Harry Ciao <qingtao.cao@windriver.com> Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
2010-02-04selinux: allow MLS->non-MLS and vice versa upon policy reloadGuido Trentalancia
Allow runtime switching between different policy types (e.g. from a MLS/MCS policy to a non-MLS/non-MCS policy or viceversa). Signed-off-by: Guido Trentalancia <guido@trentalancia.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2008-07-14selinux: support deferred mapping of contextsStephen Smalley
Introduce SELinux support for deferred mapping of security contexts in the SID table upon policy reload, and use this support for inode security contexts when the context is not yet valid under the current policy. Only processes with CAP_MAC_ADMIN + mac_admin permission in policy can set undefined security contexts on inodes. Inodes with such undefined contexts are treated as having the unlabeled context until the context becomes valid upon a policy reload that defines the context. Context invalidation upon policy reload also uses this support to save the context information in the SID table and later recover it upon a subsequent policy reload that defines the context again. This support is to enable package managers and similar programs to set down file contexts unknown to the system policy at the time the file is created in order to better support placing loadable policy modules in packages and to support build systems that need to create images of different distro releases with different policies w/o requiring all of the contexts to be defined or legal in the build host policy. With this patch applied, the following sequence is possible, although in practice it is recommended that this permission only be allowed to specific program domains such as the package manager. # rmdir baz # rm bar # touch bar # chcon -t foo_exec_t bar # foo_exec_t is not yet defined chcon: failed to change context of `bar' to `system_u:object_r:foo_exec_t': Invalid argument # mkdir -Z system_u:object_r:foo_exec_t baz mkdir: failed to set default file creation context to `system_u:object_r:foo_exec_t': Invalid argument # cat setundefined.te policy_module(setundefined, 1.0) require { type unconfined_t; type unlabeled_t; } files_type(unlabeled_t) allow unconfined_t self:capability2 mac_admin; # make -f /usr/share/selinux/devel/Makefile setundefined.pp # semodule -i setundefined.pp # chcon -t foo_exec_t bar # foo_exec_t is not yet defined # mkdir -Z system_u:object_r:foo_exec_t baz # ls -Zd bar baz -rw-r--r-- root root system_u:object_r:unlabeled_t bar drwxr-xr-x root root system_u:object_r:unlabeled_t baz # cat foo.te policy_module(foo, 1.0) type foo_exec_t; files_type(foo_exec_t) # make -f /usr/share/selinux/devel/Makefile foo.pp # semodule -i foo.pp # defines foo_exec_t # ls -Zd bar baz -rw-r--r-- root root user_u:object_r:foo_exec_t bar drwxr-xr-x root root system_u:object_r:foo_exec_t baz # semodule -r foo # ls -Zd bar baz -rw-r--r-- root root system_u:object_r:unlabeled_t bar drwxr-xr-x root root system_u:object_r:unlabeled_t baz # semodule -i foo.pp # ls -Zd bar baz -rw-r--r-- root root user_u:object_r:foo_exec_t bar drwxr-xr-x root root system_u:object_r:foo_exec_t baz # semodule -r setundefined foo # chcon -t foo_exec_t bar # no longer defined and not allowed chcon: failed to change context of `bar' to `system_u:object_r:foo_exec_t': Invalid argument # rmdir baz # mkdir -Z system_u:object_r:foo_exec_t baz mkdir: failed to set default file creation context to `system_u:object_r:foo_exec_t': Invalid argument Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2008-04-28SELinux: mls.h whitespace, syntax, and other cleanupsEric Paris
This patch changes mls.h to fix whitespace and syntax issues. Things that are fixed may include (does not not have to include) spaces used instead of tabs Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2007-11-08SELinux: add more validity checks on policy loadStephen Smalley
Add more validity checks at policy load time to reject malformed policies and prevent subsequent out-of-range indexing when in permissive mode. Resolves the NULL pointer dereference reported in https://bugzilla.redhat.com/show_bug.cgi?id=357541. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2007-01-08selinux: Delete mls_copy_contextVenkat Yekkirala
This deletes mls_copy_context() in favor of mls_context_cpy() and replaces mls_scopy_context() with mls_context_cpy_low(). Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2006-12-02NetLabel: convert to an extensibile/sparse category bitmapPaul Moore
The original NetLabel category bitmap was a straight char bitmap which worked fine for the initial release as it only supported 240 bits due to limitations in the CIPSO restricted bitmap tag (tag type 0x01). This patch converts that straight char bitmap into an extensibile/sparse bitmap in order to lay the foundation for other CIPSO tag types and protocols. This patch also has a nice side effect in that all of the security attributes passed by NetLabel into the LSM are now in a format which is in the host's native byte/bit ordering which makes the LSM specific code much simpler; look at the changes in security/selinux/ss/ebitmap.c as an example. Signed-off-by: Paul Moore <paul.moore@hp.com> Signed-off-by: James Morris <jmorris@namei.org>
2006-09-22[NetLabel]: SELinux supportVenkat Yekkirala
Add NetLabel support to the SELinux LSM and modify the socket_post_create() LSM hook to return an error code. The most significant part of this patch is the addition of NetLabel hooks into the following SELinux LSM hooks: * selinux_file_permission() * selinux_socket_sendmsg() * selinux_socket_post_create() * selinux_socket_sock_rcv_skb() * selinux_socket_getpeersec_stream() * selinux_socket_getpeersec_dgram() * selinux_sock_graft() * selinux_inet_conn_request() The basic reasoning behind this patch is that outgoing packets are "NetLabel'd" by labeling their socket and the NetLabel security attributes are checked via the additional hook in selinux_socket_sock_rcv_skb(). NetLabel itself is only a labeling mechanism, similar to filesystem extended attributes, it is up to the SELinux enforcement mechanism to perform the actual access checks. In addition to the changes outlined above this patch also includes some changes to the extended bitmap (ebitmap) and multi-level security (mls) code to import and export SELinux TE/MLS attributes into and out of NetLabel. Signed-off-by: Paul Moore <paul.moore@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-22[MLSXFRM]: Define new SELinux service routineVenkat Yekkirala
This defines a routine that combines the Type Enforcement portion of one sid with the MLS portion from the other sid to arrive at a new sid. This would be used to define a sid for a security association that is to be negotiated by IKE as well as for determing the sid for open requests and connection-oriented child sockets. Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-05-01[PATCH] support for context based audit filteringDarrel Goeddel
The following patch provides selinux interfaces that will allow the audit system to perform filtering based on the process context (user, role, type, sensitivity, and clearance). These interfaces will allow the selinux module to perform efficient matches based on lower level selinux constructs, rather than relying on context retrievals and string comparisons within the audit module. It also allows for dominance checks on the mls portion of the contexts that are impossible with only string comparisons. Signed-off-by: Darrel Goeddel <dgoeddel@trustedcs.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2005-07-28[PATCH] SELinux: default labeling of MLS fieldJames Morris
Implement kernel labeling of the MLS (multilevel security) field of security contexts for files which have no existing MLS field. This is to enable upgrades of a system from non-MLS to MLS without performing a full filesystem relabel including all of the mountpoints, which would be quite painful for users. With this patch, with MLS enabled, if a file has no MLS field, the kernel internally adds an MLS field to the in-core inode (but not to the on-disk file). This MLS field added is the default for the superblock, allowing per-mountpoint control over the values via fixed policy or mount options. This patch has been tested by enabling MLS without relabeling its filesystem, and seems to be working correctly. Signed-off-by: James Morris <jmorris@redhat.com> Signed-off-by: Stephen Smalley <sds@epoch.ncsc.mil> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!