--- /dev/null
+From 9a95c5bfbf02a0a7f5983280fe284a0ff0836c34 Mon Sep 17 00:00:00 2001
+From: GUO Zihua <guozihua@huawei.com>
+Date: Tue, 7 May 2024 01:25:41 +0000
+Subject: ima: Avoid blocking in RCU read-side critical section
+
+From: GUO Zihua <guozihua@huawei.com>
+
+commit 9a95c5bfbf02a0a7f5983280fe284a0ff0836c34 upstream.
+
+A panic happens in ima_match_policy:
+
+BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
+PGD 42f873067 P4D 0
+Oops: 0000 [#1] SMP NOPTI
+CPU: 5 PID: 1286325 Comm: kubeletmonit.sh
+Kdump: loaded Tainted: P
+Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
+ BIOS 0.0.0 02/06/2015
+RIP: 0010:ima_match_policy+0x84/0x450
+Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39
+ 7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d
+ f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea
+ 44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f
+RSP: 0018:ff71570009e07a80 EFLAGS: 00010207
+RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200
+RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000
+RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739
+R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970
+R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001
+FS: 00007f5195b51740(0000)
+GS:ff3e278b12d40000(0000) knlGS:0000000000000000
+CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0
+DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
+DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
+Call Trace:
+ ima_get_action+0x22/0x30
+ process_measurement+0xb0/0x830
+ ? page_add_file_rmap+0x15/0x170
+ ? alloc_set_pte+0x269/0x4c0
+ ? prep_new_page+0x81/0x140
+ ? simple_xattr_get+0x75/0xa0
+ ? selinux_file_open+0x9d/0xf0
+ ima_file_check+0x64/0x90
+ path_openat+0x571/0x1720
+ do_filp_open+0x9b/0x110
+ ? page_counter_try_charge+0x57/0xc0
+ ? files_cgroup_alloc_fd+0x38/0x60
+ ? __alloc_fd+0xd4/0x250
+ ? do_sys_open+0x1bd/0x250
+ do_sys_open+0x1bd/0x250
+ do_syscall_64+0x5d/0x1d0
+ entry_SYSCALL_64_after_hwframe+0x65/0xca
+
+Commit c7423dbdbc9e ("ima: Handle -ESTALE returned by
+ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a
+RCU read-side critical section which contains kmalloc with GFP_KERNEL.
+This implies a possible sleep and violates limitations of RCU read-side
+critical sections on non-PREEMPT systems.
+
+Sleeping within RCU read-side critical section might cause
+synchronize_rcu() returning early and break RCU protection, allowing a
+UAF to happen.
+
+The root cause of this issue could be described as follows:
+| Thread A | Thread B |
+| |ima_match_policy |
+| | rcu_read_lock |
+|ima_lsm_update_rule | |
+| synchronize_rcu | |
+| | kmalloc(GFP_KERNEL)|
+| | sleep |
+==> synchronize_rcu returns early
+| kfree(entry) | |
+| | entry = entry->next|
+==> UAF happens and entry now becomes NULL (or could be anything).
+| | entry->action |
+==> Accessing entry might cause panic.
+
+To fix this issue, we are converting all kmalloc that is called within
+RCU read-side critical section to use GFP_ATOMIC.
+
+Fixes: c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()")
+Cc: stable@vger.kernel.org
+Signed-off-by: GUO Zihua <guozihua@huawei.com>
+Acked-by: John Johansen <john.johansen@canonical.com>
+Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
+Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
+[PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case]
+Signed-off-by: Paul Moore <paul@paul-moore.com>
+Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ include/linux/lsm_hook_defs.h | 2 +-
+ include/linux/security.h | 5 +++--
+ kernel/auditfilter.c | 5 +++--
+ security/apparmor/audit.c | 6 +++---
+ security/apparmor/include/audit.h | 2 +-
+ security/integrity/ima/ima.h | 2 +-
+ security/integrity/ima/ima_policy.c | 15 +++++++++------
+ security/security.c | 6 ++++--
+ security/selinux/include/audit.h | 4 +++-
+ security/selinux/ss/services.c | 5 +++--
+ security/smack/smack_lsm.c | 4 +++-
+ 11 files changed, 34 insertions(+), 22 deletions(-)
+
+--- a/include/linux/lsm_hook_defs.h
++++ b/include/linux/lsm_hook_defs.h
+@@ -382,7 +382,7 @@ LSM_HOOK(int, 0, key_getsecurity, struct
+
+ #ifdef CONFIG_AUDIT
+ LSM_HOOK(int, 0, audit_rule_init, u32 field, u32 op, char *rulestr,
+- void **lsmrule)
++ void **lsmrule, gfp_t gfp)
+ LSM_HOOK(int, 0, audit_rule_known, struct audit_krule *krule)
+ LSM_HOOK(int, 0, audit_rule_match, u32 secid, u32 field, u32 op, void *lsmrule)
+ LSM_HOOK(void, LSM_RET_VOID, audit_rule_free, void *lsmrule)
+--- a/include/linux/security.h
++++ b/include/linux/security.h
+@@ -1921,7 +1921,8 @@ static inline int security_key_getsecuri
+
+ #ifdef CONFIG_AUDIT
+ #ifdef CONFIG_SECURITY
+-int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule);
++int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule,
++ gfp_t gfp);
+ int security_audit_rule_known(struct audit_krule *krule);
+ int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule);
+ void security_audit_rule_free(void *lsmrule);
+@@ -1929,7 +1930,7 @@ void security_audit_rule_free(void *lsmr
+ #else
+
+ static inline int security_audit_rule_init(u32 field, u32 op, char *rulestr,
+- void **lsmrule)
++ void **lsmrule, gfp_t gfp)
+ {
+ return 0;
+ }
+--- a/kernel/auditfilter.c
++++ b/kernel/auditfilter.c
+@@ -529,7 +529,8 @@ static struct audit_entry *audit_data_to
+ entry->rule.buflen += f_val;
+ f->lsm_str = str;
+ err = security_audit_rule_init(f->type, f->op, str,
+- (void **)&f->lsm_rule);
++ (void **)&f->lsm_rule,
++ GFP_KERNEL);
+ /* Keep currently invalid fields around in case they
+ * become valid after a policy reload. */
+ if (err == -EINVAL) {
+@@ -798,7 +799,7 @@ static inline int audit_dupe_lsm_field(s
+
+ /* our own (refreshed) copy of lsm_rule */
+ ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
+- (void **)&df->lsm_rule);
++ (void **)&df->lsm_rule, GFP_KERNEL);
+ /* Keep currently invalid fields around in case they
+ * become valid after a policy reload. */
+ if (ret == -EINVAL) {
+--- a/security/apparmor/audit.c
++++ b/security/apparmor/audit.c
+@@ -173,7 +173,7 @@ void aa_audit_rule_free(void *vrule)
+ }
+ }
+
+-int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
++int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule, gfp_t gfp)
+ {
+ struct aa_audit_rule *rule;
+
+@@ -186,14 +186,14 @@ int aa_audit_rule_init(u32 field, u32 op
+ return -EINVAL;
+ }
+
+- rule = kzalloc(sizeof(struct aa_audit_rule), GFP_KERNEL);
++ rule = kzalloc(sizeof(struct aa_audit_rule), gfp);
+
+ if (!rule)
+ return -ENOMEM;
+
+ /* Currently rules are treated as coming from the root ns */
+ rule->label = aa_label_parse(&root_ns->unconfined->label, rulestr,
+- GFP_KERNEL, true, false);
++ gfp, true, false);
+ if (IS_ERR(rule->label)) {
+ int err = PTR_ERR(rule->label);
+ aa_audit_rule_free(rule);
+--- a/security/apparmor/include/audit.h
++++ b/security/apparmor/include/audit.h
+@@ -186,7 +186,7 @@ static inline int complain_error(int err
+ }
+
+ void aa_audit_rule_free(void *vrule);
+-int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule);
++int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule, gfp_t gfp);
+ int aa_audit_rule_known(struct audit_krule *rule);
+ int aa_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule);
+
+--- a/security/integrity/ima/ima.h
++++ b/security/integrity/ima/ima.h
+@@ -428,7 +428,7 @@ static inline void ima_free_modsig(struc
+ #else
+
+ static inline int ima_filter_rule_init(u32 field, u32 op, char *rulestr,
+- void **lsmrule)
++ void **lsmrule, gfp_t gfp)
+ {
+ return -EINVAL;
+ }
+--- a/security/integrity/ima/ima_policy.c
++++ b/security/integrity/ima/ima_policy.c
+@@ -377,7 +377,8 @@ static void ima_free_rule(struct ima_rul
+ kfree(entry);
+ }
+
+-static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)
++static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry,
++ gfp_t gfp)
+ {
+ struct ima_rule_entry *nentry;
+ int i;
+@@ -386,7 +387,7 @@ static struct ima_rule_entry *ima_lsm_co
+ * Immutable elements are copied over as pointers and data; only
+ * lsm rules can change
+ */
+- nentry = kmemdup(entry, sizeof(*nentry), GFP_KERNEL);
++ nentry = kmemdup(entry, sizeof(*nentry), gfp);
+ if (!nentry)
+ return NULL;
+
+@@ -401,7 +402,8 @@ static struct ima_rule_entry *ima_lsm_co
+
+ ima_filter_rule_init(nentry->lsm[i].type, Audit_equal,
+ nentry->lsm[i].args_p,
+- &nentry->lsm[i].rule);
++ &nentry->lsm[i].rule,
++ gfp);
+ if (!nentry->lsm[i].rule)
+ pr_warn("rule for LSM \'%s\' is undefined\n",
+ nentry->lsm[i].args_p);
+@@ -414,7 +416,7 @@ static int ima_lsm_update_rule(struct im
+ int i;
+ struct ima_rule_entry *nentry;
+
+- nentry = ima_lsm_copy_rule(entry);
++ nentry = ima_lsm_copy_rule(entry, GFP_KERNEL);
+ if (!nentry)
+ return -ENOMEM;
+
+@@ -638,7 +640,7 @@ retry:
+ }
+
+ if (rc == -ESTALE && !rule_reinitialized) {
+- lsm_rule = ima_lsm_copy_rule(rule);
++ lsm_rule = ima_lsm_copy_rule(rule, GFP_ATOMIC);
+ if (lsm_rule) {
+ rule_reinitialized = true;
+ goto retry;
+@@ -1113,7 +1115,8 @@ static int ima_lsm_rule_init(struct ima_
+ entry->lsm[lsm_rule].type = audit_type;
+ result = ima_filter_rule_init(entry->lsm[lsm_rule].type, Audit_equal,
+ entry->lsm[lsm_rule].args_p,
+- &entry->lsm[lsm_rule].rule);
++ &entry->lsm[lsm_rule].rule,
++ GFP_KERNEL);
+ if (!entry->lsm[lsm_rule].rule) {
+ pr_warn("rule for LSM \'%s\' is undefined\n",
+ entry->lsm[lsm_rule].args_p);
+--- a/security/security.c
++++ b/security/security.c
+@@ -2617,9 +2617,11 @@ int security_key_getsecurity(struct key
+
+ #ifdef CONFIG_AUDIT
+
+-int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule)
++int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule,
++ gfp_t gfp)
+ {
+- return call_int_hook(audit_rule_init, 0, field, op, rulestr, lsmrule);
++ return call_int_hook(audit_rule_init, 0, field, op, rulestr, lsmrule,
++ gfp);
+ }
+
+ int security_audit_rule_known(struct audit_krule *krule)
+--- a/security/selinux/include/audit.h
++++ b/security/selinux/include/audit.h
+@@ -21,12 +21,14 @@
+ * @op: the operator the rule uses
+ * @rulestr: the text "target" of the rule
+ * @rule: pointer to the new rule structure returned via this
++ * @gfp: GFP flag used for kmalloc
+ *
+ * Returns 0 if successful, -errno if not. On success, the rule structure
+ * will be allocated internally. The caller must free this structure with
+ * selinux_audit_rule_free() after use.
+ */
+-int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **rule);
++int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **rule,
++ gfp_t gfp);
+
+ /**
+ * selinux_audit_rule_free - free an selinux audit rule structure.
+--- a/security/selinux/ss/services.c
++++ b/security/selinux/ss/services.c
+@@ -3563,7 +3563,8 @@ void selinux_audit_rule_free(void *vrule
+ }
+ }
+
+-int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
++int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule,
++ gfp_t gfp)
+ {
+ struct selinux_state *state = &selinux_state;
+ struct selinux_policy *policy;
+@@ -3604,7 +3605,7 @@ int selinux_audit_rule_init(u32 field, u
+ return -EINVAL;
+ }
+
+- tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
++ tmprule = kzalloc(sizeof(struct selinux_audit_rule), gfp);
+ if (!tmprule)
+ return -ENOMEM;
+
+--- a/security/smack/smack_lsm.c
++++ b/security/smack/smack_lsm.c
+@@ -4552,11 +4552,13 @@ static int smack_post_notification(const
+ * @op: required testing operator (=, !=, >, <, ...)
+ * @rulestr: smack label to be audited
+ * @vrule: pointer to save our own audit rule representation
++ * @gfp: type of the memory for the allocation
+ *
+ * Prepare to audit cases where (@field @op @rulestr) is true.
+ * The label to be audited is created if necessay.
+ */
+-static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
++static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule,
++ gfp_t gfp)
+ {
+ struct smack_known *skp;
+ char **rule = (char **)vrule;
projects / thirdparty / kernel / stable-queue.git / commitdiff
