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2020-08-19Smack: prevent underflow in smk_set_cipso()Dan Carpenter
[ Upstream commit 42a2df3e829f3c5562090391b33714b2e2e5ad4a ] We have an upper bound on "maplevel" but forgot to check for negative values. Fixes: e114e473771c ("Smack: Simplified Mandatory Access Control Kernel") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-19Smack: fix another vsscanf out of boundsDan Carpenter
[ Upstream commit a6bd4f6d9b07452b0b19842044a6c3ea384b0b88 ] This is similar to commit 84e99e58e8d1 ("Smack: slab-out-of-bounds in vsscanf") where we added a bounds check on "rule". Reported-by: syzbot+a22c6092d003d6fe1122@syzkaller.appspotmail.com Fixes: f7112e6c9abf ("Smack: allow for significantly longer Smack labels v4") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-11Smack: fix use-after-free in smk_write_relabel_self()Eric Biggers
commit beb4ee6770a89646659e6a2178538d2b13e2654e upstream. smk_write_relabel_self() frees memory from the task's credentials with no locking, which can easily cause a use-after-free because multiple tasks can share the same credentials structure. Fix this by using prepare_creds() and commit_creds() to correctly modify the task's credentials. Reproducer for "BUG: KASAN: use-after-free in smk_write_relabel_self": #include <fcntl.h> #include <pthread.h> #include <unistd.h> static void *thrproc(void *arg) { int fd = open("/sys/fs/smackfs/relabel-self", O_WRONLY); for (;;) write(fd, "foo", 3); } int main() { pthread_t t; pthread_create(&t, NULL, thrproc, NULL); thrproc(NULL); } Reported-by: syzbot+e6416dabb497a650da40@syzkaller.appspotmail.com Fixes: 38416e53936e ("Smack: limited capability for changing process label") Cc: <stable@vger.kernel.org> # v4.4+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22apparmor: ensure that dfa state tables have entriesJohn Johansen
commit c27c6bd2c4d6b6bb779f9b722d5607993e1d5e5c upstream. Currently it is possible to specify a state machine table with 0 length, this is not valid as optional tables are specified by not defining the table as present. Further this allows by-passing the base tables range check against the next/check tables. Fixes: d901d6a298dc ("apparmor: dfa split verification of table headers") Reported-by: Mike Salvatore <mike.salvatore@canonical.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30apparmor: don't try to replace stale label in ptraceme checkJann Horn
[ Upstream commit ca3fde5214e1d24f78269b337d3f22afd6bf445e ] begin_current_label_crit_section() must run in sleepable context because when label_is_stale() is true, aa_replace_current_label() runs, which uses prepare_creds(), which can sleep. Until now, the ptraceme access check (which runs with tasklist_lock held) violated this rule. Fixes: b2d09ae449ced ("apparmor: move ptrace checks to using labels") Reported-by: Cyrill Gorcunov <gorcunov@gmail.com> Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-25selinux: fix double freeTom Rix
commit 65de50969a77509452ae590e9449b70a22b923bb upstream. Clang's static analysis tool reports these double free memory errors. security/selinux/ss/services.c:2987:4: warning: Attempt to free released memory [unix.Malloc] kfree(bnames[i]); ^~~~~~~~~~~~~~~~ security/selinux/ss/services.c:2990:2: warning: Attempt to free released memory [unix.Malloc] kfree(bvalues); ^~~~~~~~~~~~~~ So improve the security_get_bools error handling by freeing these variables and setting their return pointers to NULL and the return len to 0 Cc: stable@vger.kernel.org Signed-off-by: Tom Rix <trix@redhat.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-25apparmor: fix nnp subset test for unconfinedJohn Johansen
[ Upstream commit 3ed4aaa94fc07db3cd0c91be95e3e1b9782a2710 ] The subset test is not taking into account the unconfined exception which will cause profile transitions in the stacked confinement case to fail when no_new_privs is applied. This fixes a regression introduced in the fix for https://bugs.launchpad.net/bugs/1839037 BugLink: https://bugs.launchpad.net/bugs/1844186 Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-25apparmor: check/put label on apparmor_sk_clone_security()Mauricio Faria de Oliveira
[ Upstream commit 3b646abc5bc6c0df649daea4c2c976bd4d47e4c8 ] Currently apparmor_sk_clone_security() does not check for existing label/peer in the 'new' struct sock; it just overwrites it, if any (with another reference to the label of the source sock.) static void apparmor_sk_clone_security(const struct sock *sk, struct sock *newsk) { struct aa_sk_ctx *ctx = SK_CTX(sk); struct aa_sk_ctx *new = SK_CTX(newsk); new->label = aa_get_label(ctx->label); new->peer = aa_get_label(ctx->peer); } This might leak label references, which might overflow under load. Thus, check for and put labels, to prevent such errors. Note this is similarly done on: static int apparmor_socket_post_create(struct socket *sock, ...) ... if (sock->sk) { struct aa_sk_ctx *ctx = SK_CTX(sock->sk); aa_put_label(ctx->label); ctx->label = aa_get_label(label); } ... Context: ------- The label reference count leak is observed if apparmor_sock_graft() is called previously: this sets the 'ctx->label' field by getting a reference to the current label (later overwritten, without put.) static void apparmor_sock_graft(struct sock *sk, ...) { struct aa_sk_ctx *ctx = SK_CTX(sk); if (!ctx->label) ctx->label = aa_get_current_label(); } And that is the case on crypto/af_alg.c:af_alg_accept(): int af_alg_accept(struct sock *sk, struct socket *newsock, ...) ... struct sock *sk2; ... sk2 = sk_alloc(...); ... security_sock_graft(sk2, newsock); security_sk_clone(sk, sk2); ... Apparently both calls are done on their own right, especially for other LSMs, being introduced in 2010/2014, before apparmor socket mediation in 2017 (see commits [1,2,3,4]). So, it looks OK there! Let's fix the reference leak in apparmor. Test-case: --------- Exercise that code path enough to overflow label reference count. $ cat aa-refcnt-af_alg.c #include <stdio.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <linux/if_alg.h> int main() { int sockfd; struct sockaddr_alg sa; /* Setup the crypto API socket */ sockfd = socket(AF_ALG, SOCK_SEQPACKET, 0); if (sockfd < 0) { perror("socket"); return 1; } memset(&sa, 0, sizeof(sa)); sa.salg_family = AF_ALG; strcpy((char *) sa.salg_type, "rng"); strcpy((char *) sa.salg_name, "stdrng"); if (bind(sockfd, (struct sockaddr *) &sa, sizeof(sa)) < 0) { perror("bind"); return 1; } /* Accept a "connection" and close it; repeat. */ while (!close(accept(sockfd, NULL, 0))); return 0; } $ gcc -o aa-refcnt-af_alg aa-refcnt-af_alg.c $ ./aa-refcnt-af_alg <a few hours later> [ 9928.475953] refcount_t overflow at apparmor_sk_clone_security+0x37/0x70 in aa-refcnt-af_alg[1322], uid/euid: 1000/1000 ... [ 9928.507443] RIP: 0010:apparmor_sk_clone_security+0x37/0x70 ... [ 9928.514286] security_sk_clone+0x33/0x50 [ 9928.514807] af_alg_accept+0x81/0x1c0 [af_alg] [ 9928.516091] alg_accept+0x15/0x20 [af_alg] [ 9928.516682] SYSC_accept4+0xff/0x210 [ 9928.519609] SyS_accept+0x10/0x20 [ 9928.520190] do_syscall_64+0x73/0x130 [ 9928.520808] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Note that other messages may be seen, not just overflow, depending on the value being incremented by kref_get(); on another run: [ 7273.182666] refcount_t: saturated; leaking memory. ... [ 7273.185789] refcount_t: underflow; use-after-free. Kprobes: ------- Using kprobe events to monitor sk -> sk_security -> label -> count (kref): Original v5.7 (one reference leak every iteration) ... (af_alg_accept+0x0/0x1c0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd2 ... (af_alg_release_parent+0x0/0xd0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd4 ... (af_alg_accept+0x0/0x1c0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd3 ... (af_alg_release_parent+0x0/0xd0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd5 ... (af_alg_accept+0x0/0x1c0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd4 ... (af_alg_release_parent+0x0/0xd0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd6 Patched v5.7 (zero reference leak per iteration) ... (af_alg_accept+0x0/0x1c0) label=0xffff9ff376c25eb0 label_refcnt=0x593 ... (af_alg_release_parent+0x0/0xd0) label=0xffff9ff376c25eb0 label_refcnt=0x594 ... (af_alg_accept+0x0/0x1c0) label=0xffff9ff376c25eb0 label_refcnt=0x593 ... (af_alg_release_parent+0x0/0xd0) label=0xffff9ff376c25eb0 label_refcnt=0x594 ... (af_alg_accept+0x0/0x1c0) label=0xffff9ff376c25eb0 label_refcnt=0x593 ... (af_alg_release_parent+0x0/0xd0) label=0xffff9ff376c25eb0 label_refcnt=0x594 Commits: ------- [1] commit 507cad355fc9 ("crypto: af_alg - Make sure sk_security is initialized on accept()ed sockets") [2] commit 4c63f83c2c2e ("crypto: af_alg - properly label AF_ALG socket") [3] commit 2acce6aa9f65 ("Networking") a.k.a ("crypto: af_alg - Avoid sock_graft call warning) [4] commit 56974a6fcfef ("apparmor: add base infastructure for socket mediation") Fixes: 56974a6fcfef ("apparmor: add base infastructure for socket mediation") Reported-by: Brian Moyles <bmoyles@netflix.com> Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-25apparmor: fix introspection of of task mode for unconfined tasksJohn Johansen
[ Upstream commit dd2569fbb053719f7df7ef8fdbb45cf47156a701 ] Fix two issues with introspecting the task mode. 1. If a task is attached to a unconfined profile that is not the ns->unconfined profile then. Mode the mode is always reported as - $ ps -Z LABEL PID TTY TIME CMD unconfined 1287 pts/0 00:00:01 bash test (-) 1892 pts/0 00:00:00 ps instead of the correct value of (unconfined) as shown below $ ps -Z LABEL PID TTY TIME CMD unconfined 2483 pts/0 00:00:01 bash test (unconfined) 3591 pts/0 00:00:00 ps 2. if a task is confined by a stack of profiles that are unconfined the output of label mode is again the incorrect value of (-) like above, instead of (unconfined). This is because the visibile profile count increment is skipped by the special casing of unconfined. Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels") Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-22ima: Call ima_calc_boot_aggregate() in ima_eventdigest_init()Roberto Sassu
[ Upstream commit 6cc7c266e5b47d3cd2b5bb7fd3aac4e6bb2dd1d2 ] If the template field 'd' is chosen and the digest to be added to the measurement entry was not calculated with SHA1 or MD5, it is recalculated with SHA1, by using the passed file descriptor. However, this cannot be done for boot_aggregate, because there is no file descriptor. This patch adds a call to ima_calc_boot_aggregate() in ima_eventdigest_init(), so that the digest can be recalculated also for the boot_aggregate entry. Cc: stable@vger.kernel.org # 3.13.x Fixes: 3ce1217d6cd5d ("ima: define template fields library and new helpers") Reported-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-22evm: Fix possible memory leak in evm_calc_hmac_or_hash()Roberto Sassu
commit 0c4395fb2aa77341269ea619c5419ea48171883f upstream. Don't immediately return if the signature is portable and security.ima is not present. Just set error so that memory allocated is freed before returning from evm_calc_hmac_or_hash(). Fixes: 50b977481fce9 ("EVM: Add support for portable signature format") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-22ima: Directly assign the ima_default_policy pointer to ima_rulesRoberto Sassu
commit 067a436b1b0aafa593344fddd711a755a58afb3b upstream. This patch prevents the following oops: [ 10.771813] BUG: kernel NULL pointer dereference, address: 0000000000000 [...] [ 10.779790] RIP: 0010:ima_match_policy+0xf7/0xb80 [...] [ 10.798576] Call Trace: [ 10.798993] ? ima_lsm_policy_change+0x2b0/0x2b0 [ 10.799753] ? inode_init_owner+0x1a0/0x1a0 [ 10.800484] ? _raw_spin_lock+0x7a/0xd0 [ 10.801592] ima_must_appraise.part.0+0xb6/0xf0 [ 10.802313] ? ima_fix_xattr.isra.0+0xd0/0xd0 [ 10.803167] ima_must_appraise+0x4f/0x70 [ 10.804004] ima_post_path_mknod+0x2e/0x80 [ 10.804800] do_mknodat+0x396/0x3c0 It occurs when there is a failure during IMA initialization, and ima_init_policy() is not called. IMA hooks still call ima_match_policy() but ima_rules is NULL. This patch prevents the crash by directly assigning the ima_default_policy pointer to ima_rules when ima_rules is defined. This wouldn't alter the existing behavior, as ima_rules is always set at the end of ima_init_policy(). Cc: stable@vger.kernel.org # 3.7.x Fixes: 07f6a79415d7d ("ima: add appraise action keywords and default rules") Reported-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-22ima: Fix ima digest hash table key calculationKrzysztof Struczynski
commit 1129d31b55d509f15e72dc68e4b5c3a4d7b4da8d upstream. Function hash_long() accepts unsigned long, while currently only one byte is passed from ima_hash_key(), which calculates a key for ima_htable. Given that hashing the digest does not give clear benefits compared to using the digest itself, remove hash_long() and return the modulus calculated on the first two bytes of the digest with the number of slots. Also reduce the depth of the hash table by doubling the number of slots. Cc: stable@vger.kernel.org Fixes: 3323eec921ef ("integrity: IMA as an integrity service provider") Co-developed-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com> Acked-by: David.Laight@aculab.com (big endian system concerns) Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-22Smack: slab-out-of-bounds in vsscanfCasey Schaufler
commit 84e99e58e8d1e26f04c097f4266e431a33987f36 upstream. Add barrier to soob. Return -EOVERFLOW if the buffer is exceeded. Suggested-by: Hillf Danton <hdanton@sina.com> Reported-by: syzbot+bfdd4a2f07be52351350@syzkaller.appspotmail.com Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-22mm: add kvfree_sensitive() for freeing sensitive data objectsWaiman Long
[ Upstream commit d4eaa2837851db2bfed572898bfc17f9a9f9151e ] For kvmalloc'ed data object that contains sensitive information like cryptographic keys, we need to make sure that the buffer is always cleared before freeing it. Using memset() alone for buffer clearing may not provide certainty as the compiler may compile it away. To be sure, the special memzero_explicit() has to be used. This patch introduces a new kvfree_sensitive() for freeing those sensitive data objects allocated by kvmalloc(). The relevant places where kvfree_sensitive() can be used are modified to use it. Fixes: 4f0882491a14 ("KEYS: Avoid false positive ENOMEM error on key read") Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Joe Perches <joe@perches.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Rientjes <rientjes@google.com> Cc: Uladzislau Rezki <urezki@gmail.com> Link: http://lkml.kernel.org/r/20200407200318.11711-1-longman@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-07evm: Fix RCU list related warningsMadhuparna Bhowmik
[ Upstream commit 770f60586d2af0590be263f55fd079226313922c ] This patch fixes the following warning and few other instances of traversal of evm_config_xattrnames list: [ 32.848432] ============================= [ 32.848707] WARNING: suspicious RCU usage [ 32.848966] 5.7.0-rc1-00006-ga8d5875ce5f0b #1 Not tainted [ 32.849308] ----------------------------- [ 32.849567] security/integrity/evm/evm_main.c:231 RCU-list traversed in non-reader section!! Since entries are only added to the list and never deleted, use list_for_each_entry_lockless() instead of list_for_each_entry_rcu for traversing the list. Also, add a relevant comment in evm_secfs.c to indicate this fact. Reported-by: kernel test robot <lkp@intel.com> Suggested-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> (RCU viewpoint) Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-03exec: Always set cap_ambient in cap_bprm_set_credsEric W. Biederman
[ Upstream commit a4ae32c71fe90794127b32d26d7ad795813b502e ] An invariant of cap_bprm_set_creds is that every field in the new cred structure that cap_bprm_set_creds might set, needs to be set every time to ensure the fields does not get a stale value. The field cap_ambient is not set every time cap_bprm_set_creds is called, which means that if there is a suid or sgid script with an interpreter that has neither the suid nor the sgid bits set the interpreter should be able to accept ambient credentials. Unfortuantely because cap_ambient is not reset to it's original value the interpreter can not accept ambient credentials. Given that the ambient capability set is expected to be controlled by the caller, I don't think this is particularly serious. But it is definitely worth fixing so the code works correctly. I have tested to verify my reading of the code is correct and the interpreter of a sgid can receive ambient capabilities with this change and cannot receive ambient capabilities without this change. Cc: stable@vger.kernel.org Cc: Andy Lutomirski <luto@kernel.org> Fixes: 58319057b784 ("capabilities: ambient capabilities") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-27apparmor: Fix aa_label refcnt leak in policy_updateXiyu Yang
commit c6b39f070722ea9963ffe756bfe94e89218c5e63 upstream. policy_update() invokes begin_current_label_crit_section(), which returns a reference of the updated aa_label object to "label" with increased refcount. When policy_update() returns, "label" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in one exception handling path of policy_update(). When aa_may_manage_policy() returns not NULL, the refcnt increased by begin_current_label_crit_section() is not decreased, causing a refcnt leak. Fix this issue by jumping to "end_section" label when aa_may_manage_policy() returns not NULL. Fixes: 5ac8c355ae00 ("apparmor: allow introspecting the loaded policy pre internal transform") Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27apparmor: fix potential label refcnt leak in aa_change_profileXiyu Yang
commit a0b845ffa0d91855532b50fc040aeb2d8338dca4 upstream. aa_change_profile() invokes aa_get_current_label(), which returns a reference of the current task's label. According to the comment of aa_get_current_label(), the returned reference must be put with aa_put_label(). However, when the original object pointed by "label" becomes unreachable because aa_change_profile() returns or a new object is assigned to "label", reference count increased by aa_get_current_label() is not decreased, causing a refcnt leak. Fix this by calling aa_put_label() before aa_change_profile() return and dropping unnecessary aa_get_current_label(). Fixes: 9fcf78cca198 ("apparmor: update domain transitions that are subsets of confinement at nnp") Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27apparmor: Fix use-after-free in aa_audit_rule_initNavid Emamdoost
commit c54d481d71c6849e044690d3960aaebc730224cc upstream. In the implementation of aa_audit_rule_init(), when aa_label_parse() fails the allocated memory for rule is released using aa_audit_rule_free(). But after this release, the return statement tries to access the label field of the rule which results in use-after-free. Before releasing the rule, copy errNo and return it after release. Fixes: 52e8c38001d8 ("apparmor: Fix memory leak of rule on error exit path") Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27ima: Fix return value of ima_write_policy()Roberto Sassu
[ Upstream commit 2e3a34e9f409ebe83d1af7cd2f49fca7af97dfac ] This patch fixes the return value of ima_write_policy() when a new policy is directly passed to IMA and the current policy requires appraisal of the file containing the policy. Currently, if appraisal is not in ENFORCE mode, ima_write_policy() returns 0 and leads user space applications to an endless loop. Fix this issue by denying the operation regardless of the appraisal mode. Cc: stable@vger.kernel.org # 4.10.x Fixes: 19f8a84713edc ("ima: measure and appraise the IMA policy itself") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-27evm: Check also if *tfm is an error pointer in init_desc()Roberto Sassu
[ Upstream commit 53de3b080d5eae31d0de219617155dcc34e7d698 ] This patch avoids a kernel panic due to accessing an error pointer set by crypto_alloc_shash(). It occurs especially when there are many files that require an unsupported algorithm, as it would increase the likelihood of the following race condition: Task A: *tfm = crypto_alloc_shash() <= error pointer Task B: if (*tfm == NULL) <= *tfm is not NULL, use it Task B: rc = crypto_shash_init(desc) <= panic Task A: *tfm = NULL This patch uses the IS_ERR_OR_NULL macro to determine whether or not a new crypto context must be created. Cc: stable@vger.kernel.org Fixes: d46eb3699502b ("evm: crypto hash replaced by shash") Co-developed-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com> Signed-off-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-27ima: Set file->f_mode instead of file->f_flags in ima_calc_file_hash()Roberto Sassu
[ Upstream commit 0014cc04e8ec077dc482f00c87dfd949cfe2b98f ] Commit a408e4a86b36 ("ima: open a new file instance if no read permissions") tries to create a new file descriptor to calculate a file digest if the file has not been opened with O_RDONLY flag. However, if a new file descriptor cannot be obtained, it sets the FMODE_READ flag to file->f_flags instead of file->f_mode. This patch fixes this issue by replacing f_flags with f_mode as it was before that commit. Cc: stable@vger.kernel.org # 4.20.x Fixes: a408e4a86b36 ("ima: open a new file instance if no read permissions") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-06selinux: properly handle multiple messages in selinux_netlink_send()Paul Moore
commit fb73974172ffaaf57a7c42f35424d9aece1a5af6 upstream. Fix the SELinux netlink_send hook to properly handle multiple netlink messages in a single sk_buff; each message is parsed and subject to SELinux access control. Prior to this patch, SELinux only inspected the first message in the sk_buff. Cc: stable@vger.kernel.org Reported-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-29KEYS: Avoid false positive ENOMEM error on key readWaiman Long
[ Upstream commit 4f0882491a148059a52480e753b7f07fc550e188 ] By allocating a kernel buffer with a user-supplied buffer length, it is possible that a false positive ENOMEM error may be returned because the user-supplied length is just too large even if the system do have enough memory to hold the actual key data. Moreover, if the buffer length is larger than the maximum amount of memory that can be returned by kmalloc() (2^(MAX_ORDER-1) number of pages), a warning message will also be printed. To reduce this possibility, we set a threshold (PAGE_SIZE) over which we do check the actual key length first before allocating a buffer of the right size to hold it. The threshold is arbitrary, it is just used to trigger a buffer length check. It does not limit the actual key length as long as there is enough memory to satisfy the memory request. To further avoid large buffer allocation failure due to page fragmentation, kvmalloc() is used to allocate the buffer so that vmapped pages can be used when there is not a large enough contiguous set of pages available for allocation. In the extremely unlikely scenario that the key keeps on being changed and made longer (still <= buflen) in between 2 __keyctl_read_key() calls, the __keyctl_read_key() calling loop in keyctl_read_key() may have to be iterated a large number of times, but definitely not infinite. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-23KEYS: Don't write out to userspace while holding key semaphoreWaiman Long
commit d3ec10aa95819bff18a0d936b18884c7816d0914 upstream. A lockdep circular locking dependency report was seen when running a keyutils test: [12537.027242] ====================================================== [12537.059309] WARNING: possible circular locking dependency detected [12537.088148] 4.18.0-147.7.1.el8_1.x86_64+debug #1 Tainted: G OE --------- - - [12537.125253] ------------------------------------------------------ [12537.153189] keyctl/25598 is trying to acquire lock: [12537.175087] 000000007c39f96c (&mm->mmap_sem){++++}, at: __might_fault+0xc4/0x1b0 [12537.208365] [12537.208365] but task is already holding lock: [12537.234507] 000000003de5b58d (&type->lock_class){++++}, at: keyctl_read_key+0x15a/0x220 [12537.270476] [12537.270476] which lock already depends on the new lock. [12537.270476] [12537.307209] [12537.307209] the existing dependency chain (in reverse order) is: [12537.340754] [12537.340754] -> #3 (&type->lock_class){++++}: [12537.367434] down_write+0x4d/0x110 [12537.385202] __key_link_begin+0x87/0x280 [12537.405232] request_key_and_link+0x483/0xf70 [12537.427221] request_key+0x3c/0x80 [12537.444839] dns_query+0x1db/0x5a5 [dns_resolver] [12537.468445] dns_resolve_server_name_to_ip+0x1e1/0x4d0 [cifs] [12537.496731] cifs_reconnect+0xe04/0x2500 [cifs] [12537.519418] cifs_readv_from_socket+0x461/0x690 [cifs] [12537.546263] cifs_read_from_socket+0xa0/0xe0 [cifs] [12537.573551] cifs_demultiplex_thread+0x311/0x2db0 [cifs] [12537.601045] kthread+0x30c/0x3d0 [12537.617906] ret_from_fork+0x3a/0x50 [12537.636225] [12537.636225] -> #2 (root_key_user.cons_lock){+.+.}: [12537.664525] __mutex_lock+0x105/0x11f0 [12537.683734] request_key_and_link+0x35a/0xf70 [12537.705640] request_key+0x3c/0x80 [12537.723304] dns_query+0x1db/0x5a5 [dns_resolver] [12537.746773] dns_resolve_server_name_to_ip+0x1e1/0x4d0 [cifs] [12537.775607] cifs_reconnect+0xe04/0x2500 [cifs] [12537.798322] cifs_readv_from_socket+0x461/0x690 [cifs] [12537.823369] cifs_read_from_socket+0xa0/0xe0 [cifs] [12537.847262] cifs_demultiplex_thread+0x311/0x2db0 [cifs] [12537.873477] kthread+0x30c/0x3d0 [12537.890281] ret_from_fork+0x3a/0x50 [12537.908649] [12537.908649] -> #1 (&tcp_ses->srv_mutex){+.+.}: [12537.935225] __mutex_lock+0x105/0x11f0 [12537.954450] cifs_call_async+0x102/0x7f0 [cifs] [12537.977250] smb2_async_readv+0x6c3/0xc90 [cifs] [12538.000659] cifs_readpages+0x120a/0x1e50 [cifs] [12538.023920] read_pages+0xf5/0x560 [12538.041583] __do_page_cache_readahead+0x41d/0x4b0 [12538.067047] ondemand_readahead+0x44c/0xc10 [12538.092069] filemap_fault+0xec1/0x1830 [12538.111637] __do_fault+0x82/0x260 [12538.129216] do_fault+0x419/0xfb0 [12538.146390] __handle_mm_fault+0x862/0xdf0 [12538.167408] handle_mm_fault+0x154/0x550 [12538.187401] __do_page_fault+0x42f/0xa60 [12538.207395] do_page_fault+0x38/0x5e0 [12538.225777] page_fault+0x1e/0x30 [12538.243010] [12538.243010] -> #0 (&mm->mmap_sem){++++}: [12538.267875] lock_acquire+0x14c/0x420 [12538.286848] __might_fault+0x119/0x1b0 [12538.306006] keyring_read_iterator+0x7e/0x170 [12538.327936] assoc_array_subtree_iterate+0x97/0x280 [12538.352154] keyring_read+0xe9/0x110 [12538.370558] keyctl_read_key+0x1b9/0x220 [12538.391470] do_syscall_64+0xa5/0x4b0 [12538.410511] entry_SYSCALL_64_after_hwframe+0x6a/0xdf [12538.435535] [12538.435535] other info that might help us debug this: [12538.435535] [12538.472829] Chain exists of: [12538.472829] &mm->mmap_sem --> root_key_user.cons_lock --> &type->lock_class [12538.472829] [12538.524820] Possible unsafe locking scenario: [12538.524820] [12538.551431] CPU0 CPU1 [12538.572654] ---- ---- [12538.595865] lock(&type->lock_class); [12538.613737] lock(root_key_user.cons_lock); [12538.644234] lock(&type->lock_class); [12538.672410] lock(&mm->mmap_sem); [12538.687758] [12538.687758] *** DEADLOCK *** [12538.687758] [12538.714455] 1 lock held by keyctl/25598: [12538.732097] #0: 000000003de5b58d (&type->lock_class){++++}, at: keyctl_read_key+0x15a/0x220 [12538.770573] [12538.770573] stack backtrace: [12538.790136] CPU: 2 PID: 25598 Comm: keyctl Kdump: loaded Tainted: G [12538.844855] Hardware name: HP ProLiant DL360 Gen9/ProLiant DL360 Gen9, BIOS P89 12/27/2015 [12538.881963] Call Trace: [12538.892897] dump_stack+0x9a/0xf0 [12538.907908] print_circular_bug.isra.25.cold.50+0x1bc/0x279 [12538.932891] ? save_trace+0xd6/0x250 [12538.948979] check_prev_add.constprop.32+0xc36/0x14f0 [12538.971643] ? keyring_compare_object+0x104/0x190 [12538.992738] ? check_usage+0x550/0x550 [12539.009845] ? sched_clock+0x5/0x10 [12539.025484] ? sched_clock_cpu+0x18/0x1e0 [12539.043555] __lock_acquire+0x1f12/0x38d0 [12539.061551] ? trace_hardirqs_on+0x10/0x10 [12539.080554] lock_acquire+0x14c/0x420 [12539.100330] ? __might_fault+0xc4/0x1b0 [12539.119079] __might_fault+0x119/0x1b0 [12539.135869] ? __might_fault+0xc4/0x1b0 [12539.153234] keyring_read_iterator+0x7e/0x170 [12539.172787] ? keyring_read+0x110/0x110 [12539.190059] assoc_array_subtree_iterate+0x97/0x280 [12539.211526] keyring_read+0xe9/0x110 [12539.227561] ? keyring_gc_check_iterator+0xc0/0xc0 [12539.249076] keyctl_read_key+0x1b9/0x220 [12539.266660] do_syscall_64+0xa5/0x4b0 [12539.283091] entry_SYSCALL_64_after_hwframe+0x6a/0xdf One way to prevent this deadlock scenario from happening is to not allow writing to userspace while holding the key semaphore. Instead, an internal buffer is allocated for getting the keys out from the read method first before copying them out to userspace without holding the lock. That requires taking out the __user modifier from all the relevant read methods as well as additional changes to not use any userspace write helpers. That is, 1) The put_user() call is replaced by a direct copy. 2) The copy_to_user() call is replaced by memcpy(). 3) All the fault handling code is removed. Compiling on a x86-64 system, the size of the rxrpc_read() function is reduced from 3795 bytes to 2384 bytes with this patch. Fixes: ^1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-21keys: Fix proc_keys_next to increase position indexVasily Averin
commit 86d32f9a7c54ad74f4514d7fef7c847883207291 upstream. If seq_file .next function does not change position index, read after some lseek can generate unexpected output: $ dd if=/proc/keys bs=1 # full usual output 0f6bfdf5 I--Q--- 2 perm 3f010000 1000 1000 user 4af2f79ab8848d0a: 740 1fb91b32 I--Q--- 3 perm 1f3f0000 1000 65534 keyring _uid.1000: 2 27589480 I--Q--- 1 perm 0b0b0000 0 0 user invocation_id: 16 2f33ab67 I--Q--- 152 perm 3f030000 0 0 keyring _ses: 2 33f1d8fa I--Q--- 4 perm 3f030000 1000 1000 keyring _ses: 1 3d427fda I--Q--- 2 perm 3f010000 1000 1000 user 69ec44aec7678e5a: 740 3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1 521+0 records in 521+0 records out 521 bytes copied, 0,00123769 s, 421 kB/s But a read after lseek in middle of last line results in the partial last line and then a repeat of the final line: $ dd if=/proc/keys bs=500 skip=1 dd: /proc/keys: cannot skip to specified offset g _uid_ses.1000: 1 3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1 0+1 records in 0+1 records out 97 bytes copied, 0,000135035 s, 718 kB/s and a read after lseek beyond end of file results in the last line being shown: $ dd if=/proc/keys bs=1000 skip=1 # read after lseek beyond end of file dd: /proc/keys: cannot skip to specified offset 3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1 0+1 records in 0+1 records out 76 bytes copied, 0,000119981 s, 633 kB/s See https://bugzilla.kernel.org/show_bug.cgi?id=206283 Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17KEYS: reaching the keys quotas correctlyYang Xu
commit 2e356101e72ab1361821b3af024d64877d9a798d upstream. Currently, when we add a new user key, the calltrace as below: add_key() key_create_or_update() key_alloc() __key_instantiate_and_link generic_key_instantiate key_payload_reserve ...... Since commit a08bf91ce28e ("KEYS: allow reaching the keys quotas exactly"), we can reach max bytes/keys in key_alloc, but we forget to remove this limit when we reserver space for payload in key_payload_reserve. So we can only reach max keys but not max bytes when having delta between plen and type->def_datalen. Remove this limit when instantiating the key, so we can keep consistent with key_alloc. Also, fix the similar problem in keyctl_chown_key(). Fixes: 0b77f5bfb45c ("keys: make the keyring quotas controllable through /proc/sys") Fixes: a08bf91ce28e ("KEYS: allow reaching the keys quotas exactly") Cc: stable@vger.kernel.org # 5.0.x Cc: Eric Biggers <ebiggers@google.com> Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-24selinux: ensure we cleanup the internal AVC counters on error in avc_update()Jaihind Yadav
[ Upstream commit 030b995ad9ece9fa2d218af4429c1c78c2342096 ] In AVC update we don't call avc_node_kill() when avc_xperms_populate() fails, resulting in the avc->avc_cache.active_nodes counter having a false value. In last patch this changes was missed , so correcting it. Fixes: fa1aa143ac4a ("selinux: extended permissions for ioctls") Signed-off-by: Jaihind Yadav <jaihindyadav@codeaurora.org> Signed-off-by: Ravi Kumar Siddojigari <rsiddoji@codeaurora.org> [PM: merge fuzz, minor description cleanup] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24selinux: ensure we cleanup the internal AVC counters on error in avc_insert()Paul Moore
[ Upstream commit d8db60cb23e49a92cf8cada3297395c7fa50fdf8 ] Fix avc_insert() to call avc_node_kill() if we've already allocated an AVC node and the code fails to insert the node in the cache. Fixes: fa1aa143ac4a ("selinux: extended permissions for ioctls") Reported-by: rsiddoji@codeaurora.org Suggested-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24selinux: fall back to ref-walk if audit is requiredStephen Smalley
[ Upstream commit 0188d5c025ca8fe756ba3193bd7d150139af5a88 ] commit bda0be7ad994 ("security: make inode_follow_link RCU-walk aware") passed down the rcu flag to the SELinux AVC, but failed to adjust the test in slow_avc_audit() to also return -ECHILD on LSM_AUDIT_DATA_DENTRY. Previously, we only returned -ECHILD if generating an audit record with LSM_AUDIT_DATA_INODE since this was only relevant from inode_permission. Move the handling of MAY_NOT_BLOCK to avc_audit() and its inlined equivalent in selinux_inode_permission() immediately after we determine that audit is required, and always fall back to ref-walk in this case. Fixes: bda0be7ad994 ("security: make inode_follow_link RCU-walk aware") Reported-by: Will Deacon <will@kernel.org> Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-05tomoyo: Use atomic_t for statistics counterTetsuo Handa
commit a8772fad0172aeae339144598b809fd8d4823331 upstream. syzbot is reporting that there is a race at tomoyo_stat_update() [1]. Although it is acceptable to fail to track exact number of times policy was updated, convert to atomic_t because this is not a hot path. [1] https://syzkaller.appspot.com/bug?id=a4d7b973972eeed410596e6604580e0133b0fc04 Reported-by: syzbot <syzbot+efea72d4a0a1d03596cd@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-27keys: Timestamp new keysDavid Howells
[ Upstream commit 7c1857bdbdf1e4c541e45eab477ee23ed4333ea4 ] Set the timestamp on new keys rather than leaving it unset. Fixes: 31d5a79d7f3d ("KEYS: Do LRU discard in full keyrings") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.morris@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-27apparmor: don't try to replace stale label in ptrace access checkJann Horn
[ Upstream commit 1f8266ff58840d698a1e96d2274189de1bdf7969 ] As a comment above begin_current_label_crit_section() explains, begin_current_label_crit_section() must run in sleepable context because when label_is_stale() is true, aa_replace_current_label() runs, which uses prepare_creds(), which can sleep. Until now, the ptrace access check (which runs with a task lock held) violated this rule. Also add a might_sleep() assertion to begin_current_label_crit_section(), because asserts are less likely to be ignored than comments. Fixes: b2d09ae449ced ("apparmor: move ptrace checks to using labels") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-27apparmor: Fix network performance issue in aa_label_sk_permTony Jones
[ Upstream commit 5f997580e8b12b9f585e34cc16304925d26ce49e ] The netperf benchmark shows a 5.73% reduction in throughput for small (64 byte) transfers by unconfined tasks. DEFINE_AUDIT_SK() in aa_label_sk_perm() should not be performed unconditionally, rather only when the label is confined. netperf-tcp 56974a6fc^ 56974a6fc Min 64 563.48 ( 0.00%) 531.17 ( -5.73%) Min 128 1056.92 ( 0.00%) 999.44 ( -5.44%) Min 256 1945.95 ( 0.00%) 1867.97 ( -4.01%) Min 1024 6761.40 ( 0.00%) 6364.23 ( -5.87%) Min 2048 11110.53 ( 0.00%) 10606.20 ( -4.54%) Min 3312 13692.67 ( 0.00%) 13158.41 ( -3.90%) Min 4096 14926.29 ( 0.00%) 14457.46 ( -3.14%) Min 8192 18399.34 ( 0.00%) 18091.65 ( -1.67%) Min 16384 21384.13 ( 0.00%) 21158.05 ( -1.06%) Hmean 64 564.96 ( 0.00%) 534.38 ( -5.41%) Hmean 128 1064.42 ( 0.00%) 1010.12 ( -5.10%) Hmean 256 1965.85 ( 0.00%) 1879.16 ( -4.41%) Hmean 1024 6839.77 ( 0.00%) 6478.70 ( -5.28%) Hmean 2048 11154.80 ( 0.00%) 10671.13 ( -4.34%) Hmean 3312 13838.12 ( 0.00%) 13249.01 ( -4.26%) Hmean 4096 15009.99 ( 0.00%) 14561.36 ( -2.99%) Hmean 8192 18975.57 ( 0.00%) 18326.54 ( -3.42%) Hmean 16384 21440.44 ( 0.00%) 21324.59 ( -0.54%) Stddev 64 1.24 ( 0.00%) 2.85 (-130.64%) Stddev 128 4.51 ( 0.00%) 6.53 ( -44.84%) Stddev 256 11.67 ( 0.00%) 8.50 ( 27.16%) Stddev 1024 48.33 ( 0.00%) 75.07 ( -55.34%) Stddev 2048 54.82 ( 0.00%) 65.16 ( -18.86%) Stddev 3312 153.57 ( 0.00%) 56.29 ( 63.35%) Stddev 4096 100.25 ( 0.00%) 88.50 ( 11.72%) Stddev 8192 358.13 ( 0.00%) 169.99 ( 52.54%) Stddev 16384 43.99 ( 0.00%) 141.82 (-222.39%) Signed-off-by: Tony Jones <tonyj@suse.de> Fixes: 56974a6fcfef ("apparmor: add base infastructure for socket mediation") Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-23LSM: generalize flag passing to security_capableMicah Morton
[ Upstream commit c1a85a00ea66cb6f0bd0f14e47c28c2b0999799f ] This patch provides a general mechanism for passing flags to the security_capable LSM hook. It replaces the specific 'audit' flag that is used to tell security_capable whether it should log an audit message for the given capability check. The reason for generalizing this flag passing is so we can add an additional flag that signifies whether security_capable is being called by a setid syscall (which is needed by the proposed SafeSetID LSM). Signed-off-by: Micah Morton <mortonm@chromium.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.morris@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-09apparmor: fix aa_xattrs_match() may sleep while holding a RCU lockJohn Johansen
commit 8c62ed27a12c00e3db1c9f04bc0f272bdbb06734 upstream. aa_xattrs_match() is unfortunately calling vfs_getxattr_alloc() from a context protected by an rcu_read_lock. This can not be done as vfs_getxattr_alloc() may sleep regardles of the gfp_t value being passed to it. Fix this by breaking the rcu_read_lock on the policy search when the xattr match feature is requested and restarting the search if a policy changes occur. Fixes: 8e51f9087f40 ("apparmor: Add support for attaching profiles via xattr, presence and value") Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com> Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-04apparmor: fix unsigned len comparison with less than zeroColin Ian King
[ Upstream commit 00e0590dbaec6f1bcaa36a85467d7e3497ced522 ] The sanity check in macro update_for_len checks to see if len is less than zero, however, len is a size_t so it can never be less than zero, so this sanity check is a no-op. Fix this by making len a ssize_t so the comparison will work and add ulen that is a size_t copy of len so that the min() macro won't throw warnings about comparing different types. Addresses-Coverity: ("Macro compares unsigned to 0") Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05apparmor: delete the dentry in aafs_remove() to avoid a leakChris Coulson
[ Upstream commit 201218e4d3dfa1346e30997f48725acce3f26d01 ] Although the apparmorfs dentries are always dropped from the dentry cache when the usage count drops to zero, there is no guarantee that this will happen in aafs_remove(), as another thread might still be using it. In this scenario, this means that the dentry will temporarily continue to appear in the results of lookups, even after the call to aafs_remove(). In the case of removal of a profile - it also causes simple_rmdir() on the profile directory to fail, as the directory won't be empty until the usage counts of all child dentries have decreased to zero. This results in the dentry for the profile directory leaking and appearing empty in the file system tree forever. Signed-off-by: Chris Coulson <chris.coulson@canonical.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-11ima: fix freeing ongoing ahash_requestSascha Hauer
[ Upstream commit 4ece3125f21b1d42b84896c5646dbf0e878464e1 ] integrity_kernel_read() can fail in which case we forward to call ahash_request_free() on a currently running request. We have to wait for its completion before we can free the request. This was observed by interrupting a "find / -type f -xdev -print0 | xargs -0 cat 1>/dev/null" with ctrl-c on an IMA enabled filesystem. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-11ima: always return negative code for errorSascha Hauer
[ Upstream commit f5e1040196dbfe14c77ce3dfe3b7b08d2d961e88 ] integrity_kernel_read() returns the number of bytes read. If this is a short read then this positive value is returned from ima_calc_file_hash_atfm(). Currently this is only indirectly called from ima_calc_file_hash() and this function only tests for the return value being zero or nonzero and also doesn't forward the return value. Nevertheless there's no point in returning a positive value as an error, so translate a short read into -EINVAL. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-07smack: use GFP_NOFS while holding inode_smack::smk_lockEric Biggers
commit e5bfad3d7acc5702f32aafeb388362994f4d7bd0 upstream. inode_smack::smk_lock is taken during smack_d_instantiate(), which is called during a filesystem transaction when creating a file on ext4. Therefore to avoid a deadlock, all code that takes this lock must use GFP_NOFS, to prevent memory reclaim from waiting for the filesystem transaction to complete. Reported-by: syzbot+0eefc1e06a77d327a056@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-07Smack: Don't ignore other bprm->unsafe flags if LSM_UNSAFE_PTRACE is setJann Horn
commit 3675f052b43ba51b99b85b073c7070e083f3e6fb upstream. There is a logic bug in the current smack_bprm_set_creds(): If LSM_UNSAFE_PTRACE is set, but the ptrace state is deemed to be acceptable (e.g. because the ptracer detached in the meantime), the other ->unsafe flags aren't checked. As far as I can tell, this means that something like the following could work (but I haven't tested it): - task A: create task B with fork() - task B: set NO_NEW_PRIVS - task B: install a seccomp filter that makes open() return 0 under some conditions - task B: replace fd 0 with a malicious library - task A: attach to task B with PTRACE_ATTACH - task B: execve() a file with an SMACK64EXEC extended attribute - task A: while task B is still in the middle of execve(), exit (which destroys the ptrace relationship) Make sure that if any flags other than LSM_UNSAFE_PTRACE are set in bprm->unsafe, we reject the execve(). Cc: stable@vger.kernel.org Fixes: 5663884caab1 ("Smack: unify all ptrace accesses in the smack") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-07security: smack: Fix possible null-pointer dereferences in ↵Jia-Ju Bai
smack_socket_sock_rcv_skb() [ Upstream commit 3f4287e7d98a2954f20bf96c567fdffcd2b63eb9 ] In smack_socket_sock_rcv_skb(), there is an if statement on line 3920 to check whether skb is NULL: if (skb && skb->secmark != 0) This check indicates skb can be NULL in some cases. But on lines 3931 and 3932, skb is used: ad.a.u.net->netif = skb->skb_iif; ipv6_skb_to_auditdata(skb, &ad.a, NULL); Thus, possible null-pointer dereferences may occur when skb is NULL. To fix these possible bugs, an if statement is added to check skb. These bugs are found by a static analysis tool STCheck written by us. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-21keys: Fix missing null pointer check in request_key_auth_describe()Hillf Danton
[ Upstream commit d41a3effbb53b1bcea41e328d16a4d046a508381 ] If a request_key authentication token key gets revoked, there's a window in which request_key_auth_describe() can see it with a NULL payload - but it makes no check for this and something like the following oops may occur: BUG: Kernel NULL pointer dereference at 0x00000038 Faulting instruction address: 0xc0000000004ddf30 Oops: Kernel access of bad area, sig: 11 [#1] ... NIP [...] request_key_auth_describe+0x90/0xd0 LR [...] request_key_auth_describe+0x54/0xd0 Call Trace: [...] request_key_auth_describe+0x54/0xd0 (unreliable) [...] proc_keys_show+0x308/0x4c0 [...] seq_read+0x3d0/0x540 [...] proc_reg_read+0x90/0x110 [...] __vfs_read+0x3c/0x70 [...] vfs_read+0xb4/0x1b0 [...] ksys_read+0x7c/0x130 [...] system_call+0x5c/0x70 Fix this by checking for a NULL pointer when describing such a key. Also make the read routine check for a NULL pointer to be on the safe side. [DH: Modified to not take already-held rcu lock and modified to also check in the read routine] Fixes: 04c567d9313e ("[PATCH] Keys: Fix race between two instantiators of a key") Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: Hillf Danton <hdanton@sina.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16apparmor: reset pos on failure to unpack for various functionsMike Salvatore
[ Upstream commit 156e42996bd84eccb6acf319f19ce0cb140d00e3 ] Each function that manipulates the aa_ext struct should reset it's "pos" member on failure. This ensures that, on failure, no changes are made to the state of the aa_ext struct. There are paths were elements are optional and the error path is used to indicate the optional element is not present. This means instead of just aborting on error the unpack stream can become unsynchronized on optional elements, if using one of the affected functions. Cc: stable@vger.kernel.org Fixes: 736ec752d95e ("AppArmor: policy routines for loading and unpacking policy") Signed-off-by: Mike Salvatore <mike.salvatore@canonical.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-06selinux: fix memory leak in policydb_init()Ondrej Mosnacek
commit 45385237f65aeee73641f1ef737d7273905a233f upstream. Since roles_init() adds some entries to the role hash table, we need to destroy also its keys/values on error, otherwise we get a memory leak in the error path. Cc: <stable@vger.kernel.org> Reported-by: syzbot+fee3a14d4cdf92646287@syzkaller.appspotmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-26selinux: fix empty write to keycreate fileOndrej Mosnacek
[ Upstream commit 464c258aa45b09f16aa0f05847ed8895873262d9 ] When sid == 0 (we are resetting keycreate_sid to the default value), we should skip the KEY__CREATE check. Before this patch, doing a zero-sized write to /proc/self/keycreate would check if the current task can create unlabeled keys (which would usually fail with -EACCESS and generate an AVC). Now it skips the check and correctly sets the task's keycreate_sid to 0. Bug report: https://bugzilla.redhat.com/show_bug.cgi?id=1719067 Tested using the reproducer from the report above. Fixes: 4eb582cf1fbd ("[PATCH] keys: add a way to store the appropriate context for newly-created keys") Reported-by: Kir Kolyshkin <kir@sacred.ru> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-25apparmor: enforce nullbyte at end of tag stringJann Horn
commit 8404d7a674c49278607d19726e0acc0cae299357 upstream. A packed AppArmor policy contains null-terminated tag strings that are read by unpack_nameX(). However, unpack_nameX() uses string functions on them without ensuring that they are actually null-terminated, potentially leading to out-of-bounds accesses. Make sure that the tag string is null-terminated before passing it to strcmp(). Cc: stable@vger.kernel.org Fixes: 736ec752d95e ("AppArmor: policy routines for loading and unpacking policy") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-25apparmor: fix PROFILE_MEDIATES for untrusted inputJohn Johansen
commit 23375b13f98c5464c2b4d15f983cc062940f1f4e upstream. While commit 11c236b89d7c2 ("apparmor: add a default null dfa") ensure every profile has a policy.dfa it does not resize the policy.start[] to have entries for every possible start value. Which means PROFILE_MEDIATES is not safe to use on untrusted input. Unforunately commit b9590ad4c4f2 ("apparmor: remove POLICY_MEDIATES_SAFE") did not take into account the start value usage. The input string in profile_query_cb() is user controlled and is not properly checked to be within the limited start[] entries, even worse it can't be as userspace policy is allowed to make us of entries types the kernel does not know about. This mean usespace can currently cause the kernel to access memory up to 240 entries beyond the start array bounds. Cc: stable@vger.kernel.org Fixes: b9590ad4c4f2 ("apparmor: remove POLICY_MEDIATES_SAFE") Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>