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2014-09-22Merge tag 'keys-next-20140922' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into nextJames Morris12-71/+82
2014-09-18Merge branch 'smack-for-3.18' of git://git.gitorious.org/smack-next/kernel into nextJames Morris5-274/+520
2014-09-16KEYS: Make the key matching functions return boolDavid Howells3-8/+8
Make the key matching functions pointed to by key_match_data::cmp return bool rather than int. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com>
2014-09-16KEYS: Remove key_type::match in favour of overriding default by match_preparseDavid Howells9-23/+15
A previous patch added a ->match_preparse() method to the key type. This is allowed to override the function called by the iteration algorithm. Therefore, we can just set a default that simply checks for an exact match of the key description with the original criterion data and allow match_preparse to override it as needed. The key_type::match op is then redundant and can be removed, as can the user_match() function. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com>
2014-09-16KEYS: Remove key_type::def_lookup_typeDavid Howells3-9/+5
Remove key_type::def_lookup_type as it's no longer used. The information now defaults to KEYRING_SEARCH_LOOKUP_DIRECT but may be overridden by type->match_preparse(). Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com>
2014-09-16KEYS: Preparse match dataDavid Howells7-44/+65
Preparse the match data. This provides several advantages: (1) The preparser can reject invalid criteria up front. (2) The preparser can convert the criteria to binary data if necessary (the asymmetric key type really wants to do binary comparison of the key IDs). (3) The preparser can set the type of search to be performed. This means that it's not then a one-off setting in the key type. (4) The preparser can set an appropriate comparator function. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com>
2014-09-16Merge tag 'keys-next-fixes-20140916' into keys-nextDavid Howells1-2/+2
Merge in keyrings fixes for next: (1) Insert some missing 'static' annotations. Signed-off-by: David Howells <dhowells@redhat.com>
2014-09-16Merge tag 'keys-fixes-20140916' into keys-nextDavid Howells1-0/+2
Merge in keyrings fixes, at least some of which later patches depend on: (1) Reinstate the production of EPERM for key types beginning with '.' in requests from userspace. (2) Tidy up the cleanup of PKCS#7 message signed information blocks and fix a bug this made more obvious. Signed-off-by: David Howells <dhowells@redhat.coM>
2014-09-16KEYS: Reinstate EPERM for a key type name beginning with a '.'David Howells1-0/+2
Reinstate the generation of EPERM for a key type name beginning with a '.' in a userspace call. Types whose name begins with a '.' are internal only. The test was removed by: commit a4e3b8d79a5c6d40f4a9703abf7fe3abcc6c3b8d Author: Mimi Zohar <zohar@linux.vnet.ibm.com> Date: Thu May 22 14:02:23 2014 -0400 Subject: KEYS: special dot prefixed keyring name bug fix I think we want to keep the restriction on type name so that userspace can't add keys of a special internal type. Note that removal of the test causes several of the tests in the keyutils testsuite to fail. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-16KEYS: Fix missing staticsDavid Howells1-2/+2
Fix missing statics (found by checker). Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com>
2014-09-09integrity: make integrity files as 'integrity' moduleDmitry Kasatkin1-3/+3
The kernel print macros use the KBUILD_MODNAME, which is initialized to the module name. The current integrity/Makefile makes every file as its own module, so pr_xxx messages are prefixed with the file name instead of the module. Similar to the evm/Makefile and ima/Makefile, this patch fixes the integrity/Makefile to use the single name 'integrity'. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09integrity: base integrity subsystem kconfig options on integrityDmitry Kasatkin3-14/+18
The integrity subsystem has lots of options and takes more than half of the security menu. This patch consolidates the options under "integrity", which are hidden if not enabled. This change does not affect existing configurations. Re-configuration is not needed. Changes v4: - no need to change "integrity subsystem" to menuconfig as options are hidden, when not enabled. (Mimi) - add INTEGRITY Kconfig help description Changes v3: - dependency to INTEGRITY removed when behind 'if INTEGRITY' Changes v2: - previous patch moved integrity out of the 'security' menu. This version keeps integrity as a security option (Mimi). Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09integrity: move asymmetric keys config optionDmitry Kasatkin1-12/+12
For better visual appearance it is better to co-locate asymmetric key options together with signature support. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09ima: initialize only required templateDmitry Kasatkin1-24/+4
IMA uses only one template. This patch initializes only required template to avoid unnecessary memory allocations. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Reviewed-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09ima: remove usage of filename parameterDmitry Kasatkin2-14/+10
In all cases except ima_bprm_check() the filename was not defined and ima_d_path() was used to find the full path. Unfortunately, the bprm filename is a relative pathname (eg. ./<dir>/filename). ima_bprm_check() selects between bprm->interp and bprm->filename. The following dump demonstrates the differences between using filename and interp. bprm->filename filename: ./foo.sh, pathname: /root/bin/foo.sh filename: ./foo.sh, pathname: /bin/dash bprm->interp filename: ./foo.sh, pathname: /root/bin/foo.sh filename: /bin/sh, pathname: /bin/dash In both cases the pathnames are currently the same. This patch removes usage of filename and interp in favor of d_absolute_path. Changes v3: - 11 extra bytes for "deleted" not needed (Mimi) - purpose "replace relative bprm filename with full pathname" (Mimi) Changes v2: - use d_absolute_path() instead of d_path to work in chroot environments. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09ima: remove unnecessary appraisal testDmitry Kasatkin1-2/+0
ima_get_action() sets the "action" flags based on policy. Before collecting, measuring, appraising, or auditing the file, the "action" flag is updated based on the cached iint->flags. This patch removes the subsequent unnecessary appraisal test in ima_appraise_measurement(). Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09ima: add missing '__init' keywordsDmitry Kasatkin3-5/+3
Add missing keywords to the function definition to cleanup to discard initialization code. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Reviewed-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09ima: remove unnecessary extra variableDmitry Kasatkin1-4/+5
'function' variable value can be changed instead of allocating extra '_func' variable. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09ima: simplify conditional statement to improve performanceDmitry Kasatkin1-4/+2
Precede bit testing before string comparison makes code faster. Also refactor statement as a single line pointer assignment. Logic is following: we set 'xattr_ptr' to read xattr value when we will do appraisal or in any case when measurement template is other than 'ima'. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09integrity: remove declaration of non-existing functionsDmitry Kasatkin2-10/+0
Commit f381c27 "integrity: move ima inode integrity data management" (re)moved few functions but left their declarations in header files. This patch removes them and also removes duplicated declaration of integrity_iint_find(). Commit c7de7ad "ima: remove unused cleanup functions". This patch removes these definitions as well. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09integrity: prevent flooding with 'Request for unknown key'Dmitry Kasatkin1-2/+3
If file has IMA signature, IMA in enforce mode, but key is missing then file access is blocked and single error message is printed. If IMA appraisal is enabled in fix mode, then system runs as usual but might produce tons of 'Request for unknown key' messages. This patch switches 'pr_warn' to 'pr_err_ratelimited'. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09ima: pass 'opened' flag to identify newly created filesDmitry Kasatkin3-12/+12
Empty files and missing xattrs do not guarantee that a file was just created. This patch passes FILE_CREATED flag to IMA to reliably identify new files. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> 3.14+
2014-09-09evm: properly handle INTEGRITY_NOXATTRS EVM statusDmitry Kasatkin1-0/+7
Unless an LSM labels a file during d_instantiate(), newly created files are not labeled with an initial security.evm xattr, until the file closes. EVM, before allowing a protected, security xattr to be written, verifies the existing 'security.evm' value is good. For newly created files without a security.evm label, this verification prevents writing any protected, security xattrs, until the file closes. Following is the example when this happens: fd = open("foo", O_CREAT | O_WRONLY, 0644); setxattr("foo", "security.SMACK64", value, sizeof(value), 0); close(fd); While INTEGRITY_NOXATTRS status is handled in other places, such as evm_inode_setattr(), it does not handle it in all cases in evm_protect_xattr(). By limiting the use of INTEGRITY_NOXATTRS to newly created files, we can now allow setting "protected" xattrs. Changelog: - limit the use of INTEGRITY_NOXATTRS to IMA identified new files Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> 3.14+
2014-09-08ima: provide flag to identify new empty filesDmitry Kasatkin3-7/+13
On ima_file_free(), newly created empty files are not labeled with an initial security.ima value, because the iversion did not change. Commit dff6efc "fs: fix iversion handling" introduced a change in iversion behavior. To verify this change use the shell command: $ (exec >foo) $ getfattr -h -e hex -d -m security foo This patch defines the IMA_NEW_FILE flag. The flag is initially set, when IMA detects that a new file is created, and subsequently checked on the ima_file_free() hook to set the initial security.ima value. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> 3.14+
2014-09-08evm: prevent passing integrity check if xattr read failsDmitry Kasatkin1-3/+4
This patch fixes a bug, where evm_verify_hmac() returns INTEGRITY_PASS if inode->i_op->getxattr() returns an error in evm_find_protected_xattrs. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
2014-09-02evm: fix checkpatch warningsDmitry Kasatkin1-3/+0
This patch fixes checkpatch 'return' warnings introduced with commit 9819cf2 "checkpatch: warn on unnecessary void function return statements". Use scripts/checkpatch.pl --file security/integrity/evm/evm_main.c to produce the warnings. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-02ima: fix fallback to use new_sync_read()Dmitry Kasatkin1-4/+4
3.16 commit aad4f8bb42af06371aa0e85bf0cd9d52c0494985 'switch simple generic_file_aio_read() users to ->read_iter()' replaced ->aio_read with ->read_iter in most of the file systems and introduced new_sync_read() as a replacement for do_sync_read(). Most of file systems set '->read' and ima_kernel_read is not affected. When ->read is not set, this patch adopts fallback call changes from the vfs_read. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> 3.16+
2014-09-02ima: prevent buffer overflow in ima_alloc_tfm()Dmitry Kasatkin1-1/+4
This patch fixes the case where the file's signature/hash xattr contains an invalid hash algorithm. Although we can not verify the xattr, we still need to measure the file. Use the default IMA hash algorithm. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-02ima: fix ima_alloc_atfm()Mimi Zohar1-1/+4
The patch 3bcced39ea7d: "ima: use ahash API for file hash calculation" from Feb 26, 2014, leads to the following static checker warning: security/integrity/ima/ima_crypto.c:204 ima_alloc_atfm()          error: buffer overflow 'hash_algo_name' 17 <= 17 Unlike shash tfm memory, which is allocated on initialization, the ahash tfm memory allocation is deferred until needed. This patch fixes the case where ima_ahash_tfm has not yet been allocated and the file's signature/hash xattr contains an invalid hash algorithm. Although we can not verify the xattr, we still need to measure the file. Use the default IMA hash algorithm. Changelog: - set valid algo before testing tfm - based on Dmitry's comment Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
2014-08-29Make Smack operate on smack_known struct where it still used char*Lukasz Pawelczyk4-255/+233
Smack used to use a mix of smack_known struct and char* throughout its APIs and implementation. This patch unifies the behaviour and makes it store and operate exclusively on smack_known struct pointers when managing labels. Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com> Conflicts: security/smack/smack_access.c security/smack/smack_lsm.c
2014-08-29Fix a bidirectional UDS connect check typoLukasz Pawelczyk1-2/+2
The 54e70ec5eb090193b03e69d551fa6771a5a217c4 commit introduced a bidirectional check that should have checked for mutual WRITE access between two labels. Due to a typo the second check was incorrect. Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>
2014-08-29Small fixes in comments describing function parametersLukasz Pawelczyk1-9/+9
Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>
2014-08-28Smack: Bring-up access modeCasey Schaufler5-27/+294
People keep asking me for permissive mode, and I keep saying "no". Permissive mode is wrong for more reasons than I can enumerate, but the compelling one is that it's once on, never off. Nonetheless, there is an argument to be made for running a process with lots of permissions, logging which are required, and then locking the process down. There wasn't a way to do that with Smack, but this provides it. The notion is that you start out by giving the process an appropriate Smack label, such as "ATBirds". You create rules with a wide range of access and the "b" mode. On Tizen it might be: ATBirds System rwxalb ATBirds User rwxalb ATBirds _ rwxalb User ATBirds wb System ATBirds wb Accesses that fail will generate audit records. Accesses that succeed because of rules marked with a "b" generate log messages identifying the rule, the program and as much object information as is convenient. When the system is properly configured and the programs brought in line with the labeling scheme the "b" mode can be removed from the rules. When the system is ready for production the facility can be configured out. This provides the developer the convenience of permissive mode without creating a system that looks like it is enforcing a policy while it is not. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2014-08-25Smack: Fix setting label on successful file openMarcin Niesluchowski1-1/+3
While opening with CAP_MAC_OVERRIDE file label is not set. Other calls may access it after CAP_MAC_OVERRIDE is dropped from process. Signed-off-by: Marcin Niesluchowski <m.niesluchow@samsung.com>
2014-08-08Smack: remove unneeded NULL-termination from securtity labelKonstantin Khlebnikov1-3/+3
Values of extended attributes are stored as binary blobs. NULL-termination of them isn't required. It just wastes disk space and confuses command-line tools like getfattr because they have to print that zero byte at the end. This patch removes terminating zero byte from initial security label in smack_inode_init_security and cuts it out in function smack_inode_getsecurity which is used by syscall getxattr. This change seems completely safe, because function smk_parse_smack ignores everything after first zero byte. Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
2014-08-08Smack: handle zero-length security labels without panicKonstantin Khlebnikov2-3/+3
Zero-length security labels are invalid but kernel should handle them. This patch fixes kernel panic after setting zero-length security labels: # attr -S -s "SMACK64" -V "" file And after writing zero-length string into smackfs files syslog and onlycp: # python -c 'import os; os.write(1, "")' > /smack/syslog The problem is caused by brain-damaged logic in function smk_parse_smack() which takes pointer to buffer and its length but if length below or equal zero it thinks that the buffer is zero-terminated. Unfortunately callers of this function are widely used and proper fix requires serious refactoring. Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
2014-08-08Smack: fix behavior of smack_inode_listsecurityKonstantin Khlebnikov1-5/+4
Security operation ->inode_listsecurity is used for generating list of available extended attributes for syscall listxattr. Currently it's used only in nfs4 or if filesystem doesn't provide i_op->listxattr. The list is the set of NULL-terminated names, one after the other. This method must include zero byte at the and into result. Also this function must return length even if string does not fit into output buffer or it is NULL, see similar method in selinux and man listxattr. Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
2014-08-02Merge branch 'next' of git://git.infradead.org/users/pcmoore/selinux into nextJames Morris5-102/+70
2014-08-01netlabel: shorter names for the NetLabel catmap funcs/structsPaul Moore5-26/+26
Historically the NetLabel LSM secattr catmap functions and data structures have had very long names which makes a mess of the NetLabel code and anyone who uses NetLabel. This patch renames the catmap functions and structures from "*_secattr_catmap_*" to just "*_catmap_*" which improves things greatly. There are no substantial code or logic changes in this patch. Signed-off-by: Paul Moore <pmoore@redhat.com> Tested-by: Casey Schaufler <casey@schaufler-ca.com>
2014-08-01netlabel: fix the horribly broken catmap functionsPaul Moore2-82/+50
The NetLabel secattr catmap functions, and the SELinux import/export glue routines, were broken in many horrible ways and the SELinux glue code fiddled with the NetLabel catmap structures in ways that we probably shouldn't allow. At some point this "worked", but that was likely due to a bit of dumb luck and sub-par testing (both inflicted by yours truly). This patch corrects these problems by basically gutting the code in favor of something less obtuse and restoring the NetLabel abstractions in the SELinux catmap glue code. Everything is working now, and if it decides to break itself in the future this code will be much easier to debug than the code it replaces. One noteworthy side effect of the changes is that it is no longer necessary to allocate a NetLabel catmap before calling one of the NetLabel APIs to set a bit in the catmap. NetLabel will automatically allocate the catmap nodes when needed, resulting in less allocations when the lowest bit is greater than 255 and less code in the LSMs. Cc: stable@vger.kernel.org Reported-by: Christian Evans <frodox@zoho.com> Signed-off-by: Paul Moore <pmoore@redhat.com> Tested-by: Casey Schaufler <casey@schaufler-ca.com>
2014-08-01netlabel: fix a problem when setting bits below the previously lowest bitPaul Moore1-1/+1
The NetLabel category (catmap) functions have a problem in that they assume categories will be set in an increasing manner, e.g. the next category set will always be larger than the last. Unfortunately, this is not a valid assumption and could result in problems when attempting to set categories less than the startbit in the lowest catmap node. In some cases kernel panics and other nasties can result. This patch corrects the problem by checking for this and allocating a new catmap node instance and placing it at the front of the list. Cc: stable@vger.kernel.org Reported-by: Christian Evans <frodox@zoho.com> Signed-off-by: Paul Moore <pmoore@redhat.com> Tested-by: Casey Schaufler <casey@schaufler-ca.com>
2014-07-30Merge branch 'stable-3.16' of git://git.infradead.org/users/pcmoore/selinux into nextJames Morris1-11/+2
2014-07-28Revert "selinux: fix the default socket labeling in sock_graft()"Paul Moore1-11/+2
This reverts commit 4da6daf4d3df5a977e4623963f141a627fd2efce. Unfortunately, the commit in question caused problems with Bluetooth devices, specifically it caused them to get caught in the newly created BUG_ON() check. The AF_ALG problem still exists, but will be addressed in a future patch. Cc: stable@vger.kernel.org Signed-off-by: Paul Moore <pmoore@redhat.com>
2014-07-28KEYS: revert encrypted key changeMimi Zohar1-1/+1
Commit fc7c70e "KEYS: struct key_preparsed_payload should have two payload pointers" erroneously modified encrypted-keys. This patch reverts the change to that file. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: David Howells <dhowells@redhat.com>
2014-07-25ima: add support for measuring and appraising firmwareMimi Zohar6-4/+41
The "security: introduce kernel_fw_from_file hook" patch defined a new security hook to evaluate any loaded firmware that wasn't built into the kernel. This patch defines ima_fw_from_file(), which is called from the new security hook, to measure and/or appraise the loaded firmware's integrity. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2014-07-25security: introduce kernel_fw_from_file hookKees Cook2-0/+12
In order to validate the contents of firmware being loaded, there must be a hook to evaluate any loaded firmware that wasn't built into the kernel itself. Without this, there is a risk that a root user could load malicious firmware designed to mount an attack against kernel memory (e.g. via DMA). Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Takashi Iwai <tiwai@suse.de>
2014-07-24CAPABILITIES: remove undefined caps from all processesEric Paris1-0/+3
This is effectively a revert of 7b9a7ec565505699f503b4fcf61500dceb36e744 plus fixing it a different way... We found, when trying to run an application from an application which had dropped privs that the kernel does security checks on undefined capability bits. This was ESPECIALLY difficult to debug as those undefined bits are hidden from /proc/$PID/status. Consider a root application which drops all capabilities from ALL 4 capability sets. We assume, since the application is going to set eff/perm/inh from an array that it will clear not only the defined caps less than CAP_LAST_CAP, but also the higher 28ish bits which are undefined future capabilities. The BSET gets cleared differently. Instead it is cleared one bit at a time. The problem here is that in security/commoncap.c::cap_task_prctl() we actually check the validity of a capability being read. So any task which attempts to 'read all things set in bset' followed by 'unset all things set in bset' will not even attempt to unset the undefined bits higher than CAP_LAST_CAP. So the 'parent' will look something like: CapInh: 0000000000000000 CapPrm: 0000000000000000 CapEff: 0000000000000000 CapBnd: ffffffc000000000 All of this 'should' be fine. Given that these are undefined bits that aren't supposed to have anything to do with permissions. But they do... So lets now consider a task which cleared the eff/perm/inh completely and cleared all of the valid caps in the bset (but not the invalid caps it couldn't read out of the kernel). We know that this is exactly what the libcap-ng library does and what the go capabilities library does. They both leave you in that above situation if you try to clear all of you capapabilities from all 4 sets. If that root task calls execve() the child task will pick up all caps not blocked by the bset. The bset however does not block bits higher than CAP_LAST_CAP. So now the child task has bits in eff which are not in the parent. These are 'meaningless' undefined bits, but still bits which the parent doesn't have. The problem is now in cred_cap_issubset() (or any operation which does a subset test) as the child, while a subset for valid cap bits, is not a subset for invalid cap bits! So now we set durring commit creds that the child is not dumpable. Given it is 'more priv' than its parent. It also means the parent cannot ptrace the child and other stupidity. The solution here: 1) stop hiding capability bits in status This makes debugging easier! 2) stop giving any task undefined capability bits. it's simple, it you don't put those invalid bits in CAP_FULL_SET you won't get them in init and you won't get them in any other task either. This fixes the cap_issubset() tests and resulting fallout (which made the init task in a docker container untraceable among other things) 3) mask out undefined bits when sys_capset() is called as it might use ~0, ~0 to denote 'all capabilities' for backward/forward compatibility. This lets 'capsh --caps="all=eip" -- -c /bin/bash' run. 4) mask out undefined bit when we read a file capability off of disk as again likely all bits are set in the xattr for forward/backward compatibility. This lets 'setcap all+pe /bin/bash; /bin/bash' run Signed-off-by: Eric Paris <eparis@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Andrew Vagin <avagin@openvz.org> Cc: Andrew G. Morgan <morgan@kernel.org> Cc: Serge E. Hallyn <serge.hallyn@canonical.com> Cc: Kees Cook <keescook@chromium.org> Cc: Steve Grubb <sgrubb@redhat.com> Cc: Dan Walsh <dwalsh@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: James Morris <james.l.morris@oracle.com>
2014-07-24Merge tag 'keys-next-20140722' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into nextJames Morris12-57/+209
2014-07-24commoncap: don't alloc the credential unless needed in cap_task_prctlTetsuo Handa1-42/+30
In function cap_task_prctl(), we would allocate a credential unconditionally and then check if we support the requested function. If not we would release this credential with abort_creds() by using RCU method. But on some archs such as powerpc, the sys_prctl is heavily used to get/set the floating point exception mode. So the unnecessary allocating/releasing of credential not only introduce runtime overhead but also do cause OOM due to the RCU implementation. This patch removes abort_creds() from cap_task_prctl() by calling prepare_creds() only when we need to modify it. Reported-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Paul Moore <paul@paul-moore.com> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.l.morris@oracle.com>
2014-07-22Merge branch 'keys-fixes' into keys-nextDavid Howells1-1/+14
Signed-off-by: David Howells <dhowells@redhat.com>