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2017-04-04KEYS: Consistent ordering for __key_link_begin and restrict checkMat Martineau
The keyring restrict callback was sometimes called before __key_link_begin and sometimes after, which meant that the keyring semaphores were not always held during the restrict callback. If the semaphores are consistently acquired before checking link restrictions, keyring contents cannot be changed after the restrict check is complete but before the evaluated key is linked to the keyring. Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
2017-04-04KEYS: Use structure to capture key restriction function and dataMat Martineau
Replace struct key's restrict_link function pointer with a pointer to the new struct key_restriction. The structure contains pointers to the restriction function as well as relevant data for evaluating the restriction. The garbage collector checks restrict_link->keytype when key types are unregistered. Restrictions involving a removed key type are converted to use restrict_link_reject so that restrictions cannot be removed by unregistering key types. Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
2017-04-03KEYS: Split role of the keyring pointer for keyring restrict functionsMat Martineau
The first argument to the restrict_link_func_t functions was a keyring pointer. These functions are called by the key subsystem with this argument set to the destination keyring, but restrict_link_by_signature expects a pointer to the relevant trusted keyring. Restrict functions may need something other than a single struct key pointer to allow or reject key linkage, so the data used to make that decision (such as the trust keyring) is moved to a new, fourth argument. The first argument is now always the destination keyring. Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
2017-04-03KEYS: Use a typedef for restrict_link function pointersMat Martineau
This pointer type needs to be returned from a lookup function, and without a typedef the syntax gets cumbersome. Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
2017-04-03security, keys: convert key_user.usage from atomic_t to refcount_tElena Reshetova
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-04-03security, keys: convert key.usage from atomic_t to refcount_tElena Reshetova
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-04-02kernel-api.rst: fix a series of errors when parsing C filesmchehab@s-opensource.com
./lib/string.c:134: WARNING: Inline emphasis start-string without end-string. ./mm/filemap.c:522: WARNING: Inline interpreted text or phrase reference start-string without end-string. ./mm/filemap.c:1283: ERROR: Unexpected indentation. ./mm/filemap.c:3003: WARNING: Inline interpreted text or phrase reference start-string without end-string. ./mm/vmalloc.c:1544: WARNING: Inline emphasis start-string without end-string. ./mm/page_alloc.c:4245: ERROR: Unexpected indentation. ./ipc/util.c:676: ERROR: Unexpected indentation. ./drivers/pci/irq.c:35: WARNING: Block quote ends without a blank line; unexpected unindent. ./security/security.c:109: ERROR: Unexpected indentation. ./security/security.c:110: WARNING: Definition list ends without a blank line; unexpected unindent. ./block/genhd.c:275: WARNING: Inline strong start-string without end-string. ./block/genhd.c:283: WARNING: Inline strong start-string without end-string. ./include/linux/clk.h:134: WARNING: Inline emphasis start-string without end-string. ./include/linux/clk.h:134: WARNING: Inline emphasis start-string without end-string. ./ipc/util.c:477: ERROR: Unknown target name: "s". Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-03-31selinux: Fix an uninitialized variable bugDan Carpenter
We removed this initialization as a cleanup but it is probably required. The concern is that "nel" can be zero. I'm not an expert on SELinux code but I think it looks possible to write an SELinux policy which triggers this bug. GCC doesn't catch this, but my static checker does. Fixes: 9c312e79d6af ("selinux: Delete an unnecessary variable initialisation in range_read()") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-30TOMOYO: Use designated initializersKees Cook
Prepare to mark sensitive kernel structures for randomization by making sure they're using designated initializers. These were identified during allyesconfig builds of x86, arm, and arm64, with most initializer fixes extracted from grsecurity. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-03-29selinux: Remove unnecessary check of array base in selinux_set_mapping()Matthias Kaehlcke
'perms' will never be NULL since it isn't a plain pointer but an array of u32 values. This fixes the following warning when building with clang: security/selinux/ss/services.c:158:16: error: address of array 'p_in->perms' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion] while (p_in->perms && p_in->perms[k]) { Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-29selinuxfs: Use seq_puts() in sel_avc_stats_seq_show()Markus Elfring
A string which did not contain data format specifications should be put into a sequence. Thus use the corresponding function "seq_puts". This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-29selinux: Adjust two checks for null pointersMarkus Elfring
The script "checkpatch.pl" pointed information out like the following. Comparison to NULL could be written !… Thus fix affected source code places. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-29selinux: Use kmalloc_array() in sidtab_init()Markus Elfring
A multiplication for the size determination of a memory allocation indicated that an array data structure should be processed. Thus use the corresponding function "kmalloc_array". This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-29selinux: Return directly after a failed kzalloc() in roles_init()Markus Elfring
Return directly after a call of the function "kzalloc" failed at the beginning. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-29selinux: Return directly after a failed kzalloc() in perm_read()Markus Elfring
Return directly after a call of the function "kzalloc" failed at the beginning. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-29selinux: Return directly after a failed kzalloc() in common_read()Markus Elfring
Return directly after a call of the function "kzalloc" failed at the beginning. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-29selinux: Return directly after a failed kzalloc() in class_read()Markus Elfring
Return directly after a call of the function "kzalloc" failed at the beginning. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-29selinux: Return directly after a failed kzalloc() in role_read()Markus Elfring
Return directly after a call of the function "kzalloc" failed at the beginning. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-29selinux: Return directly after a failed kzalloc() in type_read()Markus Elfring
Return directly after a call of the function "kzalloc" failed at the beginning. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-29selinux: Return directly after a failed kzalloc() in user_read()Markus Elfring
Return directly after a call of the function "kzalloc" failed at the beginning. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-29selinux: Improve another size determination in sens_read()Markus Elfring
Replace the specification of a data type by a pointer dereference as the parameter for the operator "sizeof" to make the corresponding size determination a bit safer according to the Linux coding style convention. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-29selinux: Return directly after a failed kzalloc() in sens_read()Markus Elfring
Return directly after a call of the function "kzalloc" failed at the beginning. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-29selinux: Return directly after a failed kzalloc() in cat_read()Markus Elfring
Return directly after a call of the function "kzalloc" failed at the beginning. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-28rtnetlink: Add RTM_DELNETCONFDavid Ahern
Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-28new helper: uaccess_kernel()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-28LSM: Revive security_task_alloc() hook and per "struct task_struct" security ↵Tetsuo Handa
blob. We switched from "struct task_struct"->security to "struct cred"->security in Linux 2.6.29. But not all LSM modules were happy with that change. TOMOYO LSM module is an example which want to use per "struct task_struct" security blob, for TOMOYO's security context is defined based on "struct task_struct" rather than "struct cred". AppArmor LSM module is another example which want to use it, for AppArmor is currently abusing the cred a little bit to store the change_hat and setexeccon info. Although security_task_free() hook was revived in Linux 3.4 because Yama LSM module wanted to release per "struct task_struct" security blob, security_task_alloc() hook and "struct task_struct"->security field were not revived. Nowadays, we are getting proposals of lightweight LSM modules which want to use per "struct task_struct" security blob. We are already allowing multiple concurrent LSM modules (up to one fully armored module which uses "struct cred"->security field or exclusive hooks like security_xfrm_state_pol_flow_match(), plus unlimited number of lightweight modules which do not use "struct cred"->security nor exclusive hooks) as long as they are built into the kernel. But this patch does not implement variable length "struct task_struct"->security field which will become needed when multiple LSM modules want to use "struct task_struct"-> security field. Although it won't be difficult to implement variable length "struct task_struct"->security field, let's think about it after we merged this patch. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: John Johansen <john.johansen@canonical.com> Acked-by: Serge Hallyn <serge@hallyn.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Tested-by: Djalal Harouni <tixxdz@gmail.com> Acked-by: José Bollo <jobol@nonadev.net> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Eric Paris <eparis@parisplace.org> Cc: Kees Cook <keescook@chromium.org> Cc: James Morris <james.l.morris@oracle.com> Cc: José Bollo <jobol@nonadev.net> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-03-24LSM: Initialize security_hook_heads upon registration.Tetsuo Handa
"struct security_hook_heads" is an array of "struct list_head" where elements can be initialized just before registration. There is no need to waste 350+ lines for initialization. Let's initialize "struct security_hook_heads" just before registration. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Kees Cook <keescook@chromium.org> Cc: John Johansen <john.johansen@canonical.com> Cc: Kees Cook <keescook@chromium.org> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: James Morris <james.l.morris@oracle.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-03-23selinux: Delete an unnecessary variable initialisation in range_read()Markus Elfring
The local variable "rt" will be set to an appropriate pointer a bit later. Thus omit the explicit initialisation at the beginning which became unnecessary with a previous update step. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-23selinux: Return directly after a failed next_entry() in range_read()Markus Elfring
Return directly after a call of the function "next_entry" failed at the beginning. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-23selinux: Delete an unnecessary variable assignment in filename_trans_read()Markus Elfring
The local variable "ft" was set to a null pointer despite of an immediate reassignment. Thus remove this statement from the beginning of a loop. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-23selinux: One function call less in genfs_read() after null pointer detectionMarkus Elfring
Call the function "kfree" at the end only after it was determined that the local variable "newgenfs" contained a non-null pointer. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-23selinux: Return directly after a failed next_entry() in genfs_read()Markus Elfring
Return directly after a call of the function "next_entry" failed at the beginning. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-23selinux: Delete an unnecessary return statement in policydb_destroy()Markus Elfring
The script "checkpatch.pl" pointed information out like the following. WARNING: void function return statements are not generally useful Thus remove such a statement in the affected function. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-23selinux: Use kcalloc() in policydb_index()Markus Elfring
Multiplications for the size determination of memory allocations indicated that array data structures should be processed. Thus use the corresponding function "kcalloc". This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-23selinux: Adjust four checks for null pointersMarkus Elfring
The script "checkpatch.pl" pointed information out like the following. Comparison to NULL could be written !… Thus fix affected source code places. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-23selinux: Use kmalloc_array() in hashtab_create()Markus Elfring
A multiplication for the size determination of a memory allocation indicated that an array data structure should be processed. Thus use the corresponding function "kmalloc_array". This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-23selinux: Improve size determinations in four functionsMarkus Elfring
Replace the specification of data structures by pointer dereferences as the parameter for the operator "sizeof" to make the corresponding size determination a bit safer. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-23selinux: Delete an unnecessary return statement in cond_compute_av()Markus Elfring
The script "checkpatch.pl" pointed information out like the following. WARNING: void function return statements are not generally useful Thus remove such a statement in the affected function. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-23selinux: Use kmalloc_array() in cond_init_bool_indexes()Markus Elfring
* A multiplication for the size determination of a memory allocation indicated that an array data structure should be processed. Thus use the corresponding function "kmalloc_array". This issue was detected by using the Coccinelle software. * Replace the specification of a data type by a pointer dereference to make the corresponding size determination a bit safer according to the Linux coding style convention. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-13ima: provide ">" and "<" operators for fowner/uid/euid rules.Mikhail Kurinnoi
For now we have only "=" operator for fowner/uid/euid rules. This patch provide two more operators - ">" and "<" in order to make fowner/uid/euid rules more flexible. Examples of usage. Appraise all files owned by special and system users (SYS_UID_MAX 999): appraise fowner<1000 Don't appraise files owned by normal users (UID_MIN 1000): dont_appraise fowner>999 Appraise all files owned by users with UID 1000-1010: dont_appraise fowner>1010 appraise fowner>999 Changelog v3: - Removed code duplication in ima_parse_rule(). - Fix ima_policy_show() - (Mimi) Changelog v2: - Fixed default policy rules. Signed-off-by: Mikhail Kurinnoi <viewizard@viewizard.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> security/integrity/ima/ima_policy.c | 115 +++++++++++++++++++++++++++--------- 1 file changed, 87 insertions(+), 28 deletions(-)
2017-03-10selinux: check for address length in selinux_socket_bind()Alexander Potapenko
KMSAN (KernelMemorySanitizer, a new error detection tool) reports use of uninitialized memory in selinux_socket_bind(): ================================================================== BUG: KMSAN: use of unitialized memory inter: 0 CPU: 3 PID: 1074 Comm: packet2 Tainted: G B 4.8.0-rc6+ #1916 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 0000000000000000 ffff8800882ffb08 ffffffff825759c8 ffff8800882ffa48 ffffffff818bf551 ffffffff85bab870 0000000000000092 ffffffff85bab550 0000000000000000 0000000000000092 00000000bb0009bb 0000000000000002 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff825759c8>] dump_stack+0x238/0x290 lib/dump_stack.c:51 [<ffffffff818bdee6>] kmsan_report+0x276/0x2e0 mm/kmsan/kmsan.c:1008 [<ffffffff818bf0fb>] __msan_warning+0x5b/0xb0 mm/kmsan/kmsan_instr.c:424 [<ffffffff822dae71>] selinux_socket_bind+0xf41/0x1080 security/selinux/hooks.c:4288 [<ffffffff8229357c>] security_socket_bind+0x1ec/0x240 security/security.c:1240 [<ffffffff84265d98>] SYSC_bind+0x358/0x5f0 net/socket.c:1366 [<ffffffff84265a22>] SyS_bind+0x82/0xa0 net/socket.c:1356 [<ffffffff81005678>] do_syscall_64+0x58/0x70 arch/x86/entry/common.c:292 [<ffffffff8518217c>] entry_SYSCALL64_slow_path+0x25/0x25 arch/x86/entry/entry_64.o:? chained origin: 00000000ba6009bb [<ffffffff810bb7a7>] save_stack_trace+0x27/0x50 arch/x86/kernel/stacktrace.c:67 [< inline >] kmsan_save_stack_with_flags mm/kmsan/kmsan.c:322 [< inline >] kmsan_save_stack mm/kmsan/kmsan.c:337 [<ffffffff818bd2b8>] kmsan_internal_chain_origin+0x118/0x1e0 mm/kmsan/kmsan.c:530 [<ffffffff818bf033>] __msan_set_alloca_origin4+0xc3/0x130 mm/kmsan/kmsan_instr.c:380 [<ffffffff84265b69>] SYSC_bind+0x129/0x5f0 net/socket.c:1356 [<ffffffff84265a22>] SyS_bind+0x82/0xa0 net/socket.c:1356 [<ffffffff81005678>] do_syscall_64+0x58/0x70 arch/x86/entry/common.c:292 [<ffffffff8518217c>] return_from_SYSCALL_64+0x0/0x6a arch/x86/entry/entry_64.o:? origin description: ----address@SYSC_bind (origin=00000000b8c00900) ================================================================== (the line numbers are relative to 4.8-rc6, but the bug persists upstream) , when I run the following program as root: ======================================================= #include <string.h> #include <sys/socket.h> #include <netinet/in.h> int main(int argc, char *argv[]) { struct sockaddr addr; int size = 0; if (argc > 1) { size = atoi(argv[1]); } memset(&addr, 0, sizeof(addr)); int fd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP); bind(fd, &addr, size); return 0; } ======================================================= (for different values of |size| other error reports are printed). This happens because bind() unconditionally copies |size| bytes of |addr| to the kernel, leaving the rest uninitialized. Then security_socket_bind() reads the IP address bytes, including the uninitialized ones, to determine the port, or e.g. pass them further to sel_netnode_find(), which uses them to calculate a hash. Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Eric Dumazet <edumazet@google.com> [PM: fixed some whitespace damage] Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-07ima: accept previously set IMA_NEW_FILEDaniel Glöckner
Modifying the attributes of a file makes ima_inode_post_setattr reset the IMA cache flags. So if the file, which has just been created, is opened a second time before the first file descriptor is closed, verification fails since the security.ima xattr has not been written yet. We therefore have to look at the IMA_NEW_FILE even if the file already existed. With this patch there should no longer be an error when cat tries to open testfile: $ rm -f testfile $ ( echo test >&3 ; touch testfile ; cat testfile ) 3>testfile A file being new is no reason to accept that it is missing a digital signature demanded by the policy. Signed-off-by: Daniel Glöckner <dg@emlix.com> Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-03-06integrity: mark default IMA rules as __ro_after_initJames Morris
The default IMA rules are loaded during init and then do not change, so mark them as __ro_after_init. Signed-off-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-03-06selinux: constify nlmsg permission tablesJames Morris
Constify nlmsg permission tables, which are initialized once and then do not change. Signed-off-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-06security: mark LSM hooks as __ro_after_initJames Morris
Mark all of the registration hooks as __ro_after_init (via the __lsm_ro_after_init macro). Signed-off-by: James Morris <james.l.morris@oracle.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Kees Cook <keescook@chromium.org>
2017-03-06security: introduce CONFIG_SECURITY_WRITABLE_HOOKSJames Morris
Subsequent patches will add RO hardening to LSM hooks, however, SELinux still needs to be able to perform runtime disablement after init to handle architectures where init-time disablement via boot parameters is not feasible. Introduce a new kernel configuration parameter CONFIG_SECURITY_WRITABLE_HOOKS, and a helper macro __lsm_ro_after_init, to handle this case. Signed-off-by: James Morris <james.l.morris@oracle.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Kees Cook <keescook@chromium.org>
2017-03-06selinux: fix kernel BUG on prlimit(..., NULL, NULL)Stephen Smalley
commit 79bcf325e6b32b3c ("prlimit,security,selinux: add a security hook for prlimit") introduced a security hook for prlimit() and implemented it for SELinux. However, if prlimit() is called with NULL arguments for both the new limit and the old limit, then the hook is called with 0 for the read/write flags, since the prlimit() will neither read nor write the process' limits. This would in turn lead to calling avc_has_perm() with 0 for the requested permissions, which triggers a BUG_ON() in avc_has_perm_noaudit() since the kernel should never be invoking avc_has_perm() with no permissions. Fix this in the SELinux hook by returning immediately if the flags are 0. Arguably prlimit64() itself ought to return immediately if both old_rlim and new_rlim are NULL since it is effectively a no-op in that case. Reported by the lkp-robot based on trinity testing. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-03-06prlimit,security,selinux: add a security hook for prlimitStephen Smalley
When SELinux was first added to the kernel, a process could only get and set its own resource limits via getrlimit(2) and setrlimit(2), so no MAC checks were required for those operations, and thus no security hooks were defined for them. Later, SELinux introduced a hook for setlimit(2) with a check if the hard limit was being changed in order to be able to rely on the hard limit value as a safe reset point upon context transitions. Later on, when prlimit(2) was added to the kernel with the ability to get or set resource limits (hard or soft) of another process, LSM/SELinux was not updated other than to pass the target process to the setrlimit hook. This resulted in incomplete control over both getting and setting the resource limits of another process. Add a new security_task_prlimit() hook to the check_prlimit_permission() function to provide complete mediation. The hook is only called when acting on another task, and only if the existing DAC/capability checks would allow access. Pass flags down to the hook to indicate whether the prlimit(2) call will read, write, or both read and write the resource limits of the target process. The existing security_task_setrlimit() hook is left alone; it continues to serve a purpose in supporting the ability to make decisions based on the old and/or new resource limit values when setting limits. This is consistent with the DAC/capability logic, where check_prlimit_permission() performs generic DAC/capability checks for acting on another task, while do_prlimit() performs a capability check based on a comparison of the old and new resource limits. Fix the inline documentation for the hook to match the code. Implement the new hook for SELinux. For setting resource limits, we reuse the existing setrlimit permission. Note that this does overload the setrlimit permission to mean the ability to set the resource limit (soft or hard) of another process or the ability to change one's own hard limit. For getting resource limits, a new getrlimit permission is defined. This was not originally defined since getrlimit(2) could only be used to obtain a process' own limits. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-03-03Merge branch 'WIP.sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull sched.h split-up from Ingo Molnar: "The point of these changes is to significantly reduce the <linux/sched.h> header footprint, to speed up the kernel build and to have a cleaner header structure. After these changes the new <linux/sched.h>'s typical preprocessed size goes down from a previous ~0.68 MB (~22K lines) to ~0.45 MB (~15K lines), which is around 40% faster to build on typical configs. Not much changed from the last version (-v2) posted three weeks ago: I eliminated quirks, backmerged fixes plus I rebased it to an upstream SHA1 from yesterday that includes most changes queued up in -next plus all sched.h changes that were pending from Andrew. I've re-tested the series both on x86 and on cross-arch defconfigs, and did a bisectability test at a number of random points. I tried to test as many build configurations as possible, but some build breakage is probably still left - but it should be mostly limited to architectures that have no cross-compiler binaries available on kernel.org, and non-default configurations" * 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (146 commits) sched/headers: Clean up <linux/sched.h> sched/headers: Remove #ifdefs from <linux/sched.h> sched/headers: Remove the <linux/topology.h> include from <linux/sched.h> sched/headers, hrtimer: Remove the <linux/wait.h> include from <linux/hrtimer.h> sched/headers, x86/apic: Remove the <linux/pm.h> header inclusion from <asm/apic.h> sched/headers, timers: Remove the <linux/sysctl.h> include from <linux/timer.h> sched/headers: Remove <linux/magic.h> from <linux/sched/task_stack.h> sched/headers: Remove <linux/sched.h> from <linux/sched/init.h> sched/core: Remove unused prefetch_stack() sched/headers: Remove <linux/rculist.h> from <linux/sched.h> sched/headers: Remove the 'init_pid_ns' prototype from <linux/sched.h> sched/headers: Remove <linux/signal.h> from <linux/sched.h> sched/headers: Remove <linux/rwsem.h> from <linux/sched.h> sched/headers: Remove the runqueue_is_locked() prototype sched/headers: Remove <linux/sched.h> from <linux/sched/hotplug.h> sched/headers: Remove <linux/sched.h> from <linux/sched/debug.h> sched/headers: Remove <linux/sched.h> from <linux/sched/nohz.h> sched/headers: Remove <linux/sched.h> from <linux/sched/stat.h> sched/headers: Remove the <linux/gfp.h> include from <linux/sched.h> sched/headers: Remove <linux/rtmutex.h> from <linux/sched.h> ...
2017-03-02sched/headers: Prepare to remove the <linux/magic.h> include from ↵Ingo Molnar
<linux/sched/task_stack.h> Update files that depend on the magic.h inclusion. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>