From 926fd9f23b27ca6587492c3f58f4c7f4cd01dad5 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Thu, 13 Jan 2022 11:44:38 -0800 Subject: ima: fix reference leak in asymmetric_verify() Don't leak a reference to the key if its algorithm is unknown. Fixes: 947d70597236 ("ima: Support EC keys for signature verification") Cc: # v5.13+ Signed-off-by: Eric Biggers Reviewed-by: Stefan Berger Reviewed-by: Tianjia Zhang Signed-off-by: Mimi Zohar --- security/integrity/digsig_asymmetric.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) (limited to 'security') diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c index 23240d793b07..895f4b9ce8c6 100644 --- a/security/integrity/digsig_asymmetric.c +++ b/security/integrity/digsig_asymmetric.c @@ -109,22 +109,25 @@ int asymmetric_verify(struct key *keyring, const char *sig, pk = asymmetric_key_public_key(key); pks.pkey_algo = pk->pkey_algo; - if (!strcmp(pk->pkey_algo, "rsa")) + if (!strcmp(pk->pkey_algo, "rsa")) { pks.encoding = "pkcs1"; - else if (!strncmp(pk->pkey_algo, "ecdsa-", 6)) + } else if (!strncmp(pk->pkey_algo, "ecdsa-", 6)) { /* edcsa-nist-p192 etc. */ pks.encoding = "x962"; - else if (!strcmp(pk->pkey_algo, "ecrdsa") || - !strcmp(pk->pkey_algo, "sm2")) + } else if (!strcmp(pk->pkey_algo, "ecrdsa") || + !strcmp(pk->pkey_algo, "sm2")) { pks.encoding = "raw"; - else - return -ENOPKG; + } else { + ret = -ENOPKG; + goto out; + } pks.digest = (u8 *)data; pks.digest_size = datalen; pks.s = hdr->sig; pks.s_size = siglen; ret = verify_signature(key, &pks); +out: key_put(key); pr_debug("%s() = %d\n", __func__, ret); return ret; -- cgit v1.2.3 From 7f5056b9e7b71149bf11073f00a57fa1ac2921a9 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Wed, 26 Jan 2022 15:35:14 -0500 Subject: security, lsm: dentry_init_security() Handle multi LSM registration A ceph user has reported that ceph is crashing with kernel NULL pointer dereference. Following is the backtrace. /proc/version: Linux version 5.16.2-arch1-1 (linux@archlinux) (gcc (GCC) 11.1.0, GNU ld (GNU Binutils) 2.36.1) #1 SMP PREEMPT Thu, 20 Jan 2022 16:18:29 +0000 distro / arch: Arch Linux / x86_64 SELinux is not enabled ceph cluster version: 16.2.7 (dd0603118f56ab514f133c8d2e3adfc983942503) relevant dmesg output: [ 30.947129] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 30.947206] #PF: supervisor read access in kernel mode [ 30.947258] #PF: error_code(0x0000) - not-present page [ 30.947310] PGD 0 P4D 0 [ 30.947342] Oops: 0000 [#1] PREEMPT SMP PTI [ 30.947388] CPU: 5 PID: 778 Comm: touch Not tainted 5.16.2-arch1-1 #1 86fbf2c313cc37a553d65deb81d98e9dcc2a3659 [ 30.947486] Hardware name: Gigabyte Technology Co., Ltd. B365M DS3H/B365M DS3H, BIOS F5 08/13/2019 [ 30.947569] RIP: 0010:strlen+0x0/0x20 [ 30.947616] Code: b6 07 38 d0 74 16 48 83 c7 01 84 c0 74 05 48 39 f7 75 ec 31 c0 31 d2 89 d6 89 d7 c3 48 89 f8 31 d2 89 d6 89 d7 c3 0 f 1f 40 00 <80> 3f 00 74 12 48 89 f8 48 83 c0 01 80 38 00 75 f7 48 29 f8 31 ff [ 30.947782] RSP: 0018:ffffa4ed80ffbbb8 EFLAGS: 00010246 [ 30.947836] RAX: 0000000000000000 RBX: ffffa4ed80ffbc60 RCX: 0000000000000000 [ 30.947904] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 30.947971] RBP: ffff94b0d15c0ae0 R08: 0000000000000000 R09: 0000000000000000 [ 30.948040] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 30.948106] R13: 0000000000000001 R14: ffffa4ed80ffbc60 R15: 0000000000000000 [ 30.948174] FS: 00007fc7520f0740(0000) GS:ffff94b7ced40000(0000) knlGS:0000000000000000 [ 30.948252] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 30.948308] CR2: 0000000000000000 CR3: 0000000104a40001 CR4: 00000000003706e0 [ 30.948376] Call Trace: [ 30.948404] [ 30.948431] ceph_security_init_secctx+0x7b/0x240 [ceph 49f9c4b9bf5be8760f19f1747e26da33920bce4b] [ 30.948582] ceph_atomic_open+0x51e/0x8a0 [ceph 49f9c4b9bf5be8760f19f1747e26da33920bce4b] [ 30.948708] ? get_cached_acl+0x4d/0xa0 [ 30.948759] path_openat+0x60d/0x1030 [ 30.948809] do_filp_open+0xa5/0x150 [ 30.948859] do_sys_openat2+0xc4/0x190 [ 30.948904] __x64_sys_openat+0x53/0xa0 [ 30.948948] do_syscall_64+0x5c/0x90 [ 30.948989] ? exc_page_fault+0x72/0x180 [ 30.949034] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 30.949091] RIP: 0033:0x7fc7521e25bb [ 30.950849] Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 0 0 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 54 24 28 64 48 2b 14 25 Core of the problem is that ceph checks for return code from security_dentry_init_security() and if return code is 0, it assumes everything is fine and continues to call strlen(name), which crashes. Typically SELinux LSM returns 0 and sets name to "security.selinux" and it is not a problem. Or if selinux is not compiled in or disabled, it returns -EOPNOTSUP and ceph deals with it. But somehow in this configuration, 0 is being returned and "name" is not being initialized and that's creating the problem. Our suspicion is that BPF LSM is registering a hook for dentry_init_security() and returns hook default of 0. LSM_HOOK(int, 0, dentry_init_security, struct dentry *dentry,...) I have not been able to reproduce it just by doing CONFIG_BPF_LSM=y. Stephen has tested the patch though and confirms it solves the problem for him. dentry_init_security() is written in such a way that it expects only one LSM to register the hook. Atleast that's the expectation with current code. If another LSM returns a hook and returns default, it will simply return 0 as of now and that will break ceph. Hence, suggestion is that change semantics of this hook a bit. If there are no LSMs or no LSM is taking ownership and initializing security context, then return -EOPNOTSUP. Also allow at max one LSM to initialize security context. This hook can't deal with multiple LSMs trying to init security context. This patch implements this new behavior. Reported-by: Stephen Muth Tested-by: Stephen Muth Suggested-by: Casey Schaufler Acked-by: Casey Schaufler Reviewed-by: Serge Hallyn Cc: Jeff Layton Cc: Christian Brauner Cc: Paul Moore Cc: # 5.16.0 Signed-off-by: Vivek Goyal Reviewed-by: Jeff Layton Acked-by: Paul Moore Acked-by: Christian Brauner Signed-off-by: James Morris --- include/linux/lsm_hook_defs.h | 2 +- security/security.c | 15 +++++++++++++-- 2 files changed, 14 insertions(+), 3 deletions(-) (limited to 'security') diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index df8de62f4710..f0c7b352340a 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -82,7 +82,7 @@ LSM_HOOK(int, 0, sb_add_mnt_opt, const char *option, const char *val, int len, void **mnt_opts) LSM_HOOK(int, 0, move_mount, const struct path *from_path, const struct path *to_path) -LSM_HOOK(int, 0, dentry_init_security, struct dentry *dentry, +LSM_HOOK(int, -EOPNOTSUPP, dentry_init_security, struct dentry *dentry, int mode, const struct qstr *name, const char **xattr_name, void **ctx, u32 *ctxlen) LSM_HOOK(int, 0, dentry_create_files_as, struct dentry *dentry, int mode, diff --git a/security/security.c b/security/security.c index c88167a414b4..64abdfb20bc2 100644 --- a/security/security.c +++ b/security/security.c @@ -1056,8 +1056,19 @@ int security_dentry_init_security(struct dentry *dentry, int mode, const char **xattr_name, void **ctx, u32 *ctxlen) { - return call_int_hook(dentry_init_security, -EOPNOTSUPP, dentry, mode, - name, xattr_name, ctx, ctxlen); + struct security_hook_list *hp; + int rc; + + /* + * Only one module will provide a security context. + */ + hlist_for_each_entry(hp, &security_hook_heads.dentry_init_security, list) { + rc = hp->hook.dentry_init_security(dentry, mode, name, + xattr_name, ctx, ctxlen); + if (rc != LSM_RET_DEFAULT(dentry_init_security)) + return rc; + } + return LSM_RET_DEFAULT(dentry_init_security); } EXPORT_SYMBOL(security_dentry_init_security); -- cgit v1.2.3 From 186edf7e368c40d06cf727a1ad14698ea67b74ad Mon Sep 17 00:00:00 2001 From: Vratislav Bendel Date: Wed, 2 Feb 2022 12:25:11 +0100 Subject: selinux: fix double free of cond_list on error paths On error path from cond_read_list() and duplicate_policydb_cond_list() the cond_list_destroy() gets called a second time in caller functions, resulting in NULL pointer deref. Fix this by resetting the cond_list_len to 0 in cond_list_destroy(), making subsequent calls a noop. Also consistently reset the cond_list pointer to NULL after freeing. Cc: stable@vger.kernel.org Signed-off-by: Vratislav Bendel [PM: fix line lengths in the description] Signed-off-by: Paul Moore --- security/selinux/ss/conditional.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'security') diff --git a/security/selinux/ss/conditional.c b/security/selinux/ss/conditional.c index 2ec6e5cd25d9..feb206f3acb4 100644 --- a/security/selinux/ss/conditional.c +++ b/security/selinux/ss/conditional.c @@ -152,6 +152,8 @@ static void cond_list_destroy(struct policydb *p) for (i = 0; i < p->cond_list_len; i++) cond_node_destroy(&p->cond_list[i]); kfree(p->cond_list); + p->cond_list = NULL; + p->cond_list_len = 0; } void cond_policydb_destroy(struct policydb *p) @@ -441,7 +443,6 @@ int cond_read_list(struct policydb *p, void *fp) return 0; err: cond_list_destroy(p); - p->cond_list = NULL; return rc; } -- cgit v1.2.3 From 83230351c523b04ff8a029a4bdf97d881ecb96fc Mon Sep 17 00:00:00 2001 From: Xiaoke Wang Date: Sat, 15 Jan 2022 09:11:11 +0800 Subject: integrity: check the return value of audit_log_start() audit_log_start() returns audit_buffer pointer on success or NULL on error, so it is better to check the return value of it. Fixes: 3323eec921ef ("integrity: IMA as an integrity service provider") Signed-off-by: Xiaoke Wang Cc: Reviewed-by: Paul Moore Signed-off-by: Mimi Zohar --- security/integrity/integrity_audit.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'security') diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c index 29220056207f..0ec5e4c22cb2 100644 --- a/security/integrity/integrity_audit.c +++ b/security/integrity/integrity_audit.c @@ -45,6 +45,8 @@ void integrity_audit_message(int audit_msgno, struct inode *inode, return; ab = audit_log_start(audit_context(), GFP_KERNEL, audit_msgno); + if (!ab) + return; audit_log_format(ab, "pid=%d uid=%u auid=%u ses=%u", task_pid_nr(current), from_kuid(&init_user_ns, current_uid()), -- cgit v1.2.3 From f7333b9572d0559e00352a926c92f29f061b4569 Mon Sep 17 00:00:00 2001 From: Stefan Berger Date: Tue, 25 Jan 2022 17:46:23 -0500 Subject: ima: Remove ima_policy file before directory The removal of ima_dir currently fails since ima_policy still exists, so remove the ima_policy file before removing the directory. Fixes: 4af4662fa4a9 ("integrity: IMA policy") Signed-off-by: Stefan Berger Cc: Acked-by: Christian Brauner Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_fs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'security') diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index 3d8e9d5db5aa..3ad8f7734208 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -496,12 +496,12 @@ int __init ima_fs_init(void) return 0; out: + securityfs_remove(ima_policy); securityfs_remove(violations); securityfs_remove(runtime_measurements_count); securityfs_remove(ascii_runtime_measurements); securityfs_remove(binary_runtime_measurements); securityfs_remove(ima_symlink); securityfs_remove(ima_dir); - securityfs_remove(ima_policy); return -1; } -- cgit v1.2.3 From bb8e52e4906f148c2faf6656b5106cf7233e9301 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Mon, 31 Jan 2022 18:11:39 +0100 Subject: ima: Allow template selection with ima_template[_fmt]= after ima_hash= Commit c2426d2ad5027 ("ima: added support for new kernel cmdline parameter ima_template_fmt") introduced an additional check on the ima_template variable to avoid multiple template selection. Unfortunately, ima_template could be also set by the setup function of the ima_hash= parameter, when it calls ima_template_desc_current(). This causes attempts to choose a new template with ima_template= or with ima_template_fmt=, after ima_hash=, to be ignored. Achieve the goal of the commit mentioned with the new static variable template_setup_done, so that template selection requests after ima_hash= are not ignored. Finally, call ima_init_template_list(), if not already done, to initialize the list of templates before lookup_template_desc() is called. Reported-by: Guo Zihua Signed-off-by: Roberto Sassu Cc: stable@vger.kernel.org Fixes: c2426d2ad5027 ("ima: added support for new kernel cmdline parameter ima_template_fmt") Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_template.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'security') diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c index 694560396be0..db1ad6d7a57f 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -29,6 +29,7 @@ static struct ima_template_desc builtin_templates[] = { static LIST_HEAD(defined_templates); static DEFINE_SPINLOCK(template_list); +static int template_setup_done; static const struct ima_template_field supported_fields[] = { {.field_id = "d", .field_init = ima_eventdigest_init, @@ -101,10 +102,11 @@ static int __init ima_template_setup(char *str) struct ima_template_desc *template_desc; int template_len = strlen(str); - if (ima_template) + if (template_setup_done) return 1; - ima_init_template_list(); + if (!ima_template) + ima_init_template_list(); /* * Verify that a template with the supplied name exists. @@ -128,6 +130,7 @@ static int __init ima_template_setup(char *str) } ima_template = template_desc; + template_setup_done = 1; return 1; } __setup("ima_template=", ima_template_setup); @@ -136,7 +139,7 @@ static int __init ima_template_fmt_setup(char *str) { int num_templates = ARRAY_SIZE(builtin_templates); - if (ima_template) + if (template_setup_done) return 1; if (template_desc_init_fields(str, NULL, NULL) < 0) { @@ -147,6 +150,7 @@ static int __init ima_template_fmt_setup(char *str) builtin_templates[num_templates - 1].fmt = str; ima_template = builtin_templates + num_templates - 1; + template_setup_done = 1; return 1; } -- cgit v1.2.3 From 89677197ae709eb1ab3646952c44f6a171c9e74c Mon Sep 17 00:00:00 2001 From: Stefan Berger Date: Tue, 1 Feb 2022 15:37:10 -0500 Subject: ima: Do not print policy rule with inactive LSM labels Before printing a policy rule scan for inactive LSM labels in the policy rule. Inactive LSM labels are identified by args_p != NULL and rule == NULL. Fixes: 483ec26eed42 ("ima: ima/lsm policy rule loading logic bug fixes") Signed-off-by: Stefan Berger Cc: # v5.6+ Acked-by: Christian Brauner [zohar@linux.ibm.com: Updated "Fixes" tag] Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_policy.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'security') diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 320ca80aacab..2a1f6418b10a 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -1967,6 +1967,14 @@ int ima_policy_show(struct seq_file *m, void *v) rcu_read_lock(); + /* Do not print rules with inactive LSM labels */ + for (i = 0; i < MAX_LSM_RULES; i++) { + if (entry->lsm[i].args_p && !entry->lsm[i].rule) { + rcu_read_unlock(); + return 0; + } + } + if (entry->action & MEASURE) seq_puts(m, pt(Opt_measure)); if (entry->action & DONT_MEASURE) -- cgit v1.2.3