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2019-12-09selinux: sidtab reverse lookup hash tableJeff Vander Stoep1-1/+10
This replaces the reverse table lookup and reverse cache with a hashtable which improves cache-miss reverse-lookup times from O(n) to O(1)* and maintains the same performance as a reverse cache hit. This reduces the time needed to add a new sidtab entry from ~500us to 5us on a Pixel 3 when there are ~10,000 sidtab entries. The implementation uses the kernel's generic hashtable API, It uses the context's string represtation as the hash source, and the kernels generic string hashing algorithm full_name_hash() to reduce the string to a 32 bit value. This change also maintains the improvement introduced in commit ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve performance") which removed the need to keep the current sidtab locked during policy reload. It does however introduce periodic locking of the target sidtab while converting the hashtable. Sidtab entries are never modified or removed, so the context struct stored in the sid_to_context tree can also be used for the context_to_sid hashtable to reduce memory usage. This bug was reported by: - On the selinux bug tracker. BUG: kernel softlockup due to too many SIDs/contexts #37 https://github.com/SELinuxProject/selinux-kernel/issues/37 - Jovana Knezevic on Android's bugtracker. Bug: 140252993 "During multi-user performance testing, we create and remove users many times. selinux_android_restorecon_pkgdir goes from 1ms to over 20ms after about 200 user creations and removals. Accumulated over ~280 packages, that adds a significant time to user creation, making perf benchmarks unreliable." * Hashtable lookup is only O(1) when n < the number of buckets. Signed-off-by: Jeff Vander Stoep <jeffv@google.com> Reported-by: Stephen Smalley <sds@tycho.nsa.gov> Reported-by: Jovana Knezevic <jovanak@google.com> Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov> Tested-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: subj tweak, removed changelog from patch description] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-10-07selinux: default_range glblub implementationJoshua Brindle1-0/+32
A policy developer can now specify glblub as a default_range default and the computed transition will be the intersection of the mls range of the two contexts. The glb (greatest lower bound) lub (lowest upper bound) of a range is calculated as the greater of the low sensitivities and the lower of the high sensitivities and the and of each category bitmap. This can be used by MLS solution developers to compute a context that satisfies, for example, the range of a network interface and the range of a user logging in. Some examples are: User Permitted Range | Network Device Label | Computed Label ---------------------|----------------------|---------------- s0-s1:c0.c12 | s0 | s0 s0-s1:c0.c12 | s0-s1:c0.c1023 | s0-s1:c0.c12 s0-s4:c0.c512 | s1-s1:c0.c1023 | s1-s1:c0.c512 s0-s15:c0,c2 | s4-s6:c0.c128 | s4-s6:c0,c2 s0-s4 | s2-s6 | s2-s4 s0-s4 | s5-s8 | INVALID s5-s8 | s0-s4 | INVALID Signed-off-by: Joshua Brindle <joshua.brindle@crunchydata.com> [PM: subject lines and checkpatch.pl fixes] 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-Hartman1-0/+1
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 Smalley1-1/+1
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>
2012-04-09SELinux: allow default source/target selectors for user/role/rangeEric Paris1-0/+20
When new objects are created we have great and flexible rules to determine the type of the new object. We aren't quite as flexible or mature when it comes to determining the user, role, and range. This patch adds a new ability to specify the place a new objects user, role, and range should come from. For users and roles it can come from either the source or the target of the operation. aka for files the user can either come from the source (the running process and todays default) or it can come from the target (aka the parent directory of the new file) examples always are done with directory context: system_u:object_r:mnt_t:s0-s0:c0.c512 process context: unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 [no rule] unconfined_u:object_r:mnt_t:s0 test_none [default user source] unconfined_u:object_r:mnt_t:s0 test_user_source [default user target] system_u:object_r:mnt_t:s0 test_user_target [default role source] unconfined_u:unconfined_r:mnt_t:s0 test_role_source [default role target] unconfined_u:object_r:mnt_t:s0 test_role_target [default range source low] unconfined_u:object_r:mnt_t:s0 test_range_source_low [default range source high] unconfined_u:object_r:mnt_t:s0:c0.c1023 test_range_source_high [default range source low-high] unconfined_u:object_r:mnt_t:s0-s0:c0.c1023 test_range_source_low-high [default range target low] unconfined_u:object_r:mnt_t:s0 test_range_target_low [default range target high] unconfined_u:object_r:mnt_t:s0:c0.c512 test_range_target_high [default range target low-high] unconfined_u:object_r:mnt_t:s0-s0:c0.c512 test_range_target_low-high Signed-off-by: Eric Paris <eparis@redhat.com>
2010-02-04selinux: allow MLS->non-MLS and vice versa upon policy reloadGuido Trentalancia1-12/+0
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>
2009-01-05SELinux: shrink sizeof av_inhert selinux_class_perm and contextEric Paris1-1/+1
I started playing with pahole today and decided to put it against the selinux structures. Found we could save a little bit of space on x86_64 (and no harm on i686) just reorganizing some structs. Object size changes: av_inherit: 24 -> 16 selinux_class_perm: 48 -> 40 context: 80 -> 72 Admittedly there aren't many of av_inherit or selinux_class_perm's in the kernel (33 and 1 respectively) But the change to the size of struct context reverberate out a bit. I can get some hard number if they are needed, but I don't see why they would be. We do change which cacheline context->len and context->str would be on, but I don't see that as a problem since we are clearly going to have to load both if the context is to be of any value. I've run with the patch and don't seem to be having any problems. An example of what's going on using struct av_inherit would be: form: to: struct av_inherit { struct av_inherit { u16 tclass; const char **common_pts; const char **common_pts; u32 common_base; u32 common_base; u16 tclass; }; (notice all I did was move u16 tclass to the end of the struct instead of the beginning) Memory layout before the change: struct av_inherit { u16 tclass; /* 2 */ /* 6 bytes hole */ const char** common_pts; /* 8 */ u32 common_base; /* 4 */ /* 4 byes padding */ /* size: 24, cachelines: 1 */ /* sum members: 14, holes: 1, sum holes: 6 */ /* padding: 4 */ }; Memory layout after the change: struct av_inherit { const char ** common_pts; /* 8 */ u32 common_base; /* 4 */ u16 tclass; /* 2 */ /* 2 bytes padding */ /* size: 16, cachelines: 1 */ /* sum members: 14, holes: 0, sum holes: 0 */ /* padding: 2 */ }; Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-07-14selinux: support deferred mapping of contextsStephen Smalley1-1/+26
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: context.h whitespace, syntax, and other cleanupsEric Paris1-2/+2
This patch changes context.h to fix whitespace and syntax issues. Things that are fixed may include (does not not have to include) include spaces around , in function calls Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2007-01-08selinux: Delete mls_copy_contextVenkat Yekkirala1-0/+23
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>
2005-04-16Linux-2.6.12-rc2Linus Torvalds1-0/+107
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!