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2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-01-17Subject: [PATCH] Smack: mmap controls for library containmentCasey Schaufler
In the embedded world there are often situations where libraries are updated from a variety of sources, for a variety of reasons, and with any number of security characteristics. These differences might include privilege required for a given library provided interface to function properly, as occurs from time to time in graphics libraries. There are also cases where it is important to limit use of libraries based on the provider of the library and the security aware application may make choices based on that criteria. These issues are addressed by providing an additional Smack label that may optionally be assigned to an object, the SMACK64MMAP attribute. An mmap operation is allowed if there is no such attribute. If there is a SMACK64MMAP attribute the mmap is permitted only if a subject with that label has all of the access permitted a subject with the current task label. Security aware applications may from time to time wish to reduce their "privilege" to avoid accidental use of privilege. One case where this arises is the environment in which multiple sources provide libraries to perform the same functions. An application may know that it should eschew services made available from a particular vendor, or of a particular version. In support of this a secondary list of Smack rules has been added that is local to the task. This list is consulted only in the case where the global list has approved access. It can only further restrict access. Unlike the global last, if no entry is found on the local list access is granted. An application can add entries to its own list by writing to /smack/load-self. The changes appear large as they involve refactoring the list handling to accomodate there being more than one rule list. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2010-12-07Smack: Transmute labels on specified directoriesJarkko Sakkinen
In a situation where Smack access rules allow processes with multiple labels to write to a directory it is easy to get into a situation where the directory gets cluttered with files that the owner can't deal with because while they could be written to the directory a process at the label of the directory can't write them. This is generally the desired behavior, but when it isn't it is a real issue. This patch introduces a new attribute SMACK64TRANSMUTE that instructs Smack to create the file with the label of the directory under certain circumstances. A new access mode, "t" for transmute, is made available to Smack access rules, which are expanded from "rwxa" to "rwxat". If a file is created in a directory marked as transmutable and if access was granted to perform the operation by a rule that included the transmute mode, then the file gets the Smack label of the directory instead of the Smack label of the creating process. Note that this is equivalent to creating an empty file at the label of the directory and then having the other process write to it. The transmute scheme requires that both the access rule allows transmutation and that the directory be explicitly marked. Signed-off-by: Jarkko Sakkinen <ext-jarkko.2.sakkinen@nokia.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2010-12-02This patch adds a new security attribute to Smack calledCasey Schaufler
SMACK64EXEC. It defines label that is used while task is running. Exception: in smack_task_wait() child task is checked for write access to parent task using label inherited from the task that forked it. Fixed issues from previous submit: - SMACK64EXEC was not read when SMACK64 was not set. - inode security blob was not updated after setting SMACK64EXEC - inode security blob was not updated when removing SMACK64EXEC
2010-10-29convert get_sb_single() usersAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-15llseek: automatically add .llseek fopArnd Bergmann
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2009-09-23seq_file: constify seq_operationsJames Morris
Make all seq_operations structs const, to help mitigate against revectoring user-triggerable function pointers. This is derived from the grsecurity patch, although generated from scratch because it's simpler than extracting the changes from there. Signed-off-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (44 commits) nommu: Provide mmap_min_addr definition. TOMOYO: Add description of lists and structures. TOMOYO: Remove unused field. integrity: ima audit dentry_open failure TOMOYO: Remove unused parameter. security: use mmap_min_addr indepedently of security models TOMOYO: Simplify policy reader. TOMOYO: Remove redundant markers. SELinux: define audit permissions for audit tree netlink messages TOMOYO: Remove unused mutex. tomoyo: avoid get+put of task_struct smack: Remove redundant initialization. integrity: nfsd imbalance bug fix rootplug: Remove redundant initialization. smack: do not beyond ARRAY_SIZE of data integrity: move ima_counts_get integrity: path_check update IMA: Add __init notation to ima functions IMA: Minimal IMA policy and boot param for TCB IMA policy selinux: remove obsolete read buffer limit from sel_read_bool ...
2009-05-22smack: do not beyond ARRAY_SIZE of dataRoel Kluin
Do not go beyond ARRAY_SIZE of data Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-04-15rculist: use list_entry_rcu in places where it's appropriateJiri Pirko
Use previously introduced list_entry_rcu instead of an open-coded list_entry + rcu_dereference combination. Signed-off-by: Jiri Pirko <jpirko@redhat.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: dipankar@in.ibm.com LKML-Reference: <20090414181715.GA3634@psychotron.englab.brq.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14smack: implement logging V3Etienne Basset
the following patch, add logging of Smack security decisions. This is of course very useful to understand what your current smack policy does. As suggested by Casey, it also now forbids labels with ', " or \ It introduces a '/smack/logging' switch : 0: no logging 1: log denied (default) 2: log accepted 3: log denied&accepted Signed-off-by: Etienne Basset <etienne.basset@numericable.fr> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-03-28smack: Add a new '-CIPSO' option to the network address label configurationEtienne Basset
This patch adds a new special option '-CIPSO' to the Smack subsystem. When used in the netlabel list, it means "use CIPSO networking". A use case is when your local network speaks CIPSO and you want also to connect to the unlabeled Internet. This patch also add some documentation describing that. The patch also corrects an oops when setting a '' SMACK64 xattr to a file. Signed-off-by: Etienne Basset <etienne.basset@numericable.fr> Signed-off-by: Paul Moore <paul.moore@hp.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-03-26smack: convert smack to standard linux listsEtienne Basset
the following patch (on top of 2.6.29) converts Smack lists to standard linux lists Please review and consider for inclusion in 2.6.30-rc regards, Etienne Signed-off-by: Etienne Basset <etienne.basset@numericable.fr> Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2009-03-05smack: fixes for unlabeled host supportetienne
The following patch (against 2.6.29rc5) fixes a few issues in the smack/netlabel "unlabeled host support" functionnality that was added in 2.6.29rc. It should go in before -final. 1) smack_host_label disregard a "0.0.0.0/0 @" rule (or other label), preventing 'tagged' tasks to access Internet (many systems drop packets with IP options) 2) netmasks were not handled correctly, they were stored in a way _not equivalent_ to conversion to be32 (it was equivalent for /0, /8, /16, /24, /32 masks but not other masks) 3) smack_netlbladdr prefixes (IP/mask) were not consistent (mask&IP was not done), so there could have been different list entries for the same IP prefix; if those entries had different labels, well ... 4) they were not sorted 1) 2) 3) are bugs, 4) is a more cosmetic issue. The patch : -creates a new helper smk_netlbladdr_insert to insert a smk_netlbladdr, -sorted by netmask length -use the new sorted nature of smack_netlbladdrs list to simplify smack_host_label : the first match _will_ be the more specific -corrects endianness issues in smk_write_netlbladdr & netlbladdr_seq_show Signed-off-by: <etienne.basset@numericable.fr> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Paul Moore <paul.moore@hp.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-19smack: fix lots of kernel-doc notationRandy Dunlap
Fix/add kernel-doc notation and fix typos in security/smack/. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-27smackfs load append mode fixCasey Schaufler
Given just how hard it is to find the code that uses MAY_APPEND it's probably not a big surprise that this went unnoticed for so long. The Smack rules loading code is incorrectly setting the MAY_READ bit when MAY_APPEND is requested. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08remove lots of double-semicolonsFernando Carrijo
Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Theodore Ts'o <tytso@mit.edu> Acked-by: Mark Fasheh <mfasheh@suse.com> Acked-by: David S. Miller <davem@davemloft.net> Cc: James Morris <jmorris@namei.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-31smack: Add support for unlabeled network hosts and networksCasey Schaufler
Add support for unlabeled network hosts and networks. Relies heavily on Paul Moore's netlabel support. Creates a new entry in /smack called netlabel. Writes to /smack/netlabel take the form: A.B.C.D LABEL or A.B.C.D/N LABEL where A.B.C.D is a network address, N is an integer between 0-32, and LABEL is the Smack label to be used. If /N is omitted /32 is assumed. N designates the netmask for the address. Entries are matched by the most specific address/mask pair. 0.0.0.0/0 will match everything, while 192.168.1.117/32 will match exactly one host. A new system label "@", pronounced "web", is defined. Processes can not be assigned the web label. An address assigned the web label can be written to by any process, and packets coming from a web address can be written to any socket. Use of the web label is a violation of any strict MAC policy, but the web label has been requested many times. The nltype entry has been removed from /smack. It did not work right and the netlabel interface can be used to specify that all hosts be treated as unlabeled. CIPSO labels on incoming packets will be honored, even from designated single label hosts. Single label hosts can only be written to by processes with labels that can write to the label of the host. Packets sent to single label hosts will always be unlabeled. Once added a single label designation cannot be removed, however the label may be changed. The behavior of the ambient label remains unchanged. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul.moore@hp.com>
2008-12-31netlabel: Update kernel configuration APIPaul Moore
Update the NetLabel kernel API to expose the new features added in kernel releases 2.6.25 and 2.6.28: the static/fallback label functionality and network address based selectors. Signed-off-by: Paul Moore <paul.moore@hp.com>
2008-12-25smackfs: check for allocation failures in smk_set_access()Sergio Luis
smackfs: check for allocation failures in smk_set_access() While adding a new subject/object pair to smack_list, smk_set_access() didn't check the return of kzalloc(). This patch changes smk_set_access() to return 0 or -ENOMEM, based on kzalloc()'s return. It also updates its caller, smk_write_load(), to check for smk_set_access()'s return, given it is no longer a void return function. Signed-off-by: Sergio Luis <sergio@larces.uece.br> To: Casey Schaufler <casey@schaufler-ca.com> Cc: Ahmed S. Darwish <darwish.07@gmail.com> Cc: LSM <linux-security-module@vger.kernel.org> Cc: LKLM <linux-kernel@vger.kernel.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2008-11-14CRED: Wrap current->cred and a few other accessorsDavid Howells
Wrap current->cred and a few other accessors to hide their actual implementation. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14CRED: Separate task security context from task_structDavid Howells
Separate the task security context from task_struct. At this point, the security data is temporarily embedded in the task_struct with two pointers pointing to it. Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in entry.S via asm-offsets. With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-10-11Merge branch 'master' of ↵James Morris
git://git.infradead.org/users/pcmoore/lblnet-2.6_next into next
2008-10-10netlabel: Replace protocol/NetLabel linking with refrerence countsPaul Moore
NetLabel has always had a list of backpointers in the CIPSO DOI definition structure which pointed to the NetLabel LSM domain mapping structures which referenced the CIPSO DOI struct. The rationale for this was that when an administrator removed a CIPSO DOI from the system all of the associated NetLabel LSM domain mappings should be removed as well; a list of backpointers made this a simple operation. Unfortunately, while the backpointers did make the removal easier they were a bit of a mess from an implementation point of view which was making further development difficult. Since the removal of a CIPSO DOI is a realtively rare event it seems to make sense to remove this backpointer list as the optimization was hurting us more then it was helping. However, we still need to be able to track when a CIPSO DOI definition is being used so replace the backpointer list with a reference count. In order to preserve the current functionality of removing the associated LSM domain mappings when a CIPSO DOI is removed we walk the LSM domain mapping table, removing the relevant entries. Signed-off-by: Paul Moore <paul.moore@hp.com> Reviewed-by: James Morris <jmorris@namei.org>
2008-08-05smack: limit privilege by labelCasey Schaufler
There have been a number of requests to make the Smack LSM enforce MAC even in the face of privilege, either capability based or superuser based. This is not universally desired, however, so it seems desirable to make it optional. Further, at least one legacy OS implemented a scheme whereby only processes running with one particular label could be exempt from MAC. This patch supports these three cases. If /smack/onlycap is empty (unset or null-string) privilege is enforced in the normal way. If /smack/onlycap contains a label only processes running with that label may be MAC exempt. If the label in /smack/onlycap is the star label ("*") the semantics of the star label combine with the privilege restrictions to prevent any violations of MAC, even in the presence of privilege. Again, this will be independent of the privilege scheme. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: James Morris <jmorris@namei.org>
2008-04-29Merge branch 'audit.b50' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current * 'audit.b50' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current: [PATCH] new predicate - AUDIT_FILETYPE [patch 2/2] Use find_task_by_vpid in audit code [patch 1/2] audit: let userspace fully control TTY input auditing [PATCH 2/2] audit: fix sparse shadowed variable warnings [PATCH 1/2] audit: move extern declarations to audit.h Audit: MAINTAINERS update Audit: increase the maximum length of the key field Audit: standardize string audit interfaces Audit: stop deadlock from signals under load Audit: save audit_backlog_limit audit messages in case auditd comes back Audit: collect sessionid in netlink messages Audit: end printk with newline
2008-04-28smack: make smk_cipso_doi() and smk_unlbl_ambient()Casey Schaufler
The functions smk_cipso_doi and smk_unlbl_ambient are not used outside smackfs.c and should hence be static. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28Audit: collect sessionid in netlink messagesEric Paris
Previously I added sessionid output to all audit messages where it was available but we still didn't know the sessionid of the sender of netlink messages. This patch adds that information to netlink messages so we can audit who sent netlink messages. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-19Security: Introduce security= boot parameterAhmed S. Darwish
Add the security= boot parameter. This is done to avoid LSM registration clashes in case of more than one bult-in module. User can choose a security module to enable at boot. If no security= boot parameter is specified, only the first LSM asking for registration will be loaded. An invalid security module name will be treated as if no module has been chosen. LSM modules must check now if they are allowed to register by calling security_module_enable(ops) first. Modify SELinux and SMACK to do so. Do not let SMACK register smackfs if it was not chosen on boot. Smackfs assumes that smack hooks are registered and the initial task security setup (swapper->security) is done. Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Acked-by: James Morris <jmorris@namei.org>
2008-03-24smackfs: remove redundant lock, fix open(,O_RDWR)Ahmed S. Darwish
Older smackfs was parsing MAC rules by characters, thus a need of locking write sessions on open() was needed. This lock is no longer useful now since each rule is handled by a single write() call. This is also a bugfix since seq_open() was not called if an open() O_RDWR flag was given, leading to a seq_read() without an initialized seq_file, thus an Oops. Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Reported-by: Jonathan Corbet <corbet@lwn.net> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-13smackfs: do not trust `count' in inodes write()sAhmed S. Darwish
Smackfs write() implementation does not put a higher bound on the number of bytes to copy from user-space. This may lead to a DOS attack if a malicious `count' field is given. Assure that given `count' is exactly the length needed for a /smack/load rule. In case of /smack/cipso where the length is relative, assure that `count' does not exceed the size needed for a buffer representing maximum possible number of CIPSO 2.2 categories. Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-19Smack: unlabeled outgoing ambient packetsCasey Schaufler
Smack uses CIPSO labeling, but allows for unlabeled packets by specifying an "ambient" label that is applied to incoming unlabeled packets. Because the other end of the connection may dislike IP options, and ssh is one know application that behaves thus, it is prudent to respond in kind. This patch changes the network labeling behavior such that an outgoing packet that would be given a CIPSO label that matches the ambient label is left unlabeled. An "unlbl" domain is added and the netlabel defaulting mechanism invoked rather than assuming that everything is CIPSO. Locking has been added around changes to the ambient label as the mechanisms used to do so are more involved. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Paul Moore <paul.moore@hp.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05Smack: Simplified Mandatory Access Control KernelCasey Schaufler
Smack is the Simplified Mandatory Access Control Kernel. Smack implements mandatory access control (MAC) using labels attached to tasks and data containers, including files, SVIPC, and other tasks. Smack is a kernel based scheme that requires an absolute minimum of application support and a very small amount of configuration data. Smack uses extended attributes and provides a set of general mount options, borrowing technics used elsewhere. Smack uses netlabel for CIPSO labeling. Smack provides a pseudo-filesystem smackfs that is used for manipulation of system Smack attributes. The patch, patches for ls and sshd, a README, a startup script, and x86 binaries for ls and sshd are also available on http://www.schaufler-ca.com Development has been done using Fedora Core 7 in a virtual machine environment and on an old Sony laptop. Smack provides mandatory access controls based on the label attached to a task and the label attached to the object it is attempting to access. Smack labels are deliberately short (1-23 characters) text strings. Single character labels using special characters are reserved for system use. The only operation applied to Smack labels is equality comparison. No wildcards or expressions, regular or otherwise, are used. Smack labels are composed of printable characters and may not include "/". A file always gets the Smack label of the task that created it. Smack defines and uses these labels: "*" - pronounced "star" "_" - pronounced "floor" "^" - pronounced "hat" "?" - pronounced "huh" The access rules enforced by Smack are, in order: 1. Any access requested by a task labeled "*" is denied. 2. A read or execute access requested by a task labeled "^" is permitted. 3. A read or execute access requested on an object labeled "_" is permitted. 4. Any access requested on an object labeled "*" is permitted. 5. Any access requested by a task on an object with the same label is permitted. 6. Any access requested that is explicitly defined in the loaded rule set is permitted. 7. Any other access is denied. Rules may be explicitly defined by writing subject,object,access triples to /smack/load. Smack rule sets can be easily defined that describe Bell&LaPadula sensitivity, Biba integrity, and a variety of interesting configurations. Smack rule sets can be modified on the fly to accommodate changes in the operating environment or even the time of day. Some practical use cases: Hierarchical levels. The less common of the two usual uses for MLS systems is to define hierarchical levels, often unclassified, confidential, secret, and so on. To set up smack to support this, these rules could be defined: C Unclass rx S C rx S Unclass rx TS S rx TS C rx TS Unclass rx A TS process can read S, C, and Unclass data, but cannot write it. An S process can read C and Unclass. Note that specifying that TS can read S and S can read C does not imply TS can read C, it has to be explicitly stated. Non-hierarchical categories. This is the more common of the usual uses for an MLS system. Since the default rule is that a subject cannot access an object with a different label no access rules are required to implement compartmentalization. A case that the Bell & LaPadula policy does not allow is demonstrated with this Smack access rule: A case that Bell&LaPadula does not allow that Smack does: ESPN ABC r ABC ESPN r On my portable video device I have two applications, one that shows ABC programming and the other ESPN programming. ESPN wants to show me sport stories that show up as news, and ABC will only provide minimal information about a sports story if ESPN is covering it. Each side can look at the other's info, neither can change the other. Neither can see what FOX is up to, which is just as well all things considered. Another case that I especially like: SatData Guard w Guard Publish w A program running with the Guard label opens a UDP socket and accepts messages sent by a program running with a SatData label. The Guard program inspects the message to ensure it is wholesome and if it is sends it to a program running with the Publish label. This program then puts the information passed in an appropriate place. Note that the Guard program cannot write to a Publish file system object because file system semanitic require read as well as write. The four cases (categories, levels, mutual read, guardbox) here are all quite real, and problems I've been asked to solve over the years. The first two are easy to do with traditonal MLS systems while the last two you can't without invoking privilege, at least for a while. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Cc: Joshua Brindle <method@manicmethod.com> Cc: Paul Moore <paul.moore@hp.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Chris Wright <chrisw@sous-sol.org> Cc: James Morris <jmorris@namei.org> Cc: "Ahmed S. Darwish" <darwish.07@gmail.com> Cc: Andrew G. Morgan <morgan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>