kernel/linux.git/security, branch v4.19.141

Smack: prevent underflow in smk_set_cipso()

2020-08-19T06:14:59+00:00

[ 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 Signed-off-by: Casey Schaufler Signed-off-by: Sasha Levin

Smack: fix another vsscanf out of bounds

2020-08-19T06:14:59+00:00

[ 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 Signed-off-by: Casey Schaufler Signed-off-by: Sasha Levin

Smack: fix use-after-free in smk_write_relabel_self()

2020-08-11T13:32:36+00:00

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 #include #include 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: # v4.4+ Signed-off-by: Eric Biggers Signed-off-by: Casey Schaufler Signed-off-by: Greg Kroah-Hartman

apparmor: ensure that dfa state tables have entries

2020-07-22T07:32:06+00:00

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 Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: don't try to replace stale label in ptraceme check

2020-07-01T03:17:03+00:00

[ 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 Reported-by: kernel test robot Signed-off-by: Jann Horn Signed-off-by: John Johansen Signed-off-by: Sasha Levin

selinux: fix double free

2020-06-25T13:33:07+00:00

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 Acked-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

apparmor: fix nnp subset test for unconfined

2020-06-25T13:32:52+00:00

[ 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 Signed-off-by: Sasha Levin

apparmor: check/put label on apparmor_sk_clone_security()

2020-06-25T13:32:52+00:00

[ 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 #include #include #include #include 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 [ 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 Signed-off-by: Mauricio Faria de Oliveira Signed-off-by: John Johansen Signed-off-by: Sasha Levin

apparmor: fix introspection of of task mode for unconfined tasks

2020-06-25T13:32:51+00:00

[ 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 Signed-off-by: Sasha Levin

ima: Call ima_calc_boot_aggregate() in ima_eventdigest_init()

2020-06-22T07:05:26+00:00

[ 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 Signed-off-by: Roberto Sassu Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin