FAILED: patch "[PATCH] ima: Avoid blocking in RCU read-side critical section" failed to apply to 6.1-stable tree
Subsystems (8)
[email protected]
maintainerThe patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 9a95c5bfbf02a0a7f5983280fe284a0ff0836c34
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2024062440-setting-progeny-529f@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
9a95c5bfbf02 ("ima: Avoid blocking in RCU read-side critical section") 260017f31a8c ("lsm: use default hook return value in call_int_hook()") 923831117611 ("evm: Move to LSM infrastructure")84594c9ecdca ("ima: Move IMA-Appraisal to LSM infrastructure") cd3cec0a02c7 ("ima: Move to LSM infrastructure")06cca5110774 ("integrity: Move integrity_kernel_module_request() to IMA") b8d997032a46 ("security: Introduce key_post_create_or_update hook") 2d705d802414 ("security: Introduce inode_post_remove_acl hook") 8b9d0b825c65 ("security: Introduce inode_post_set_acl hook")a7811e34d100 ("security: Introduce inode_post_create_tmpfile hook") f09068b5a114 ("security: Introduce file_release hook")8f46ff5767b0 ("security: Introduce file_post_open hook")dae52cbf5887 ("security: Introduce inode_post_removexattr hook") 77fa6f314f03 ("security: Introduce inode_post_setattr hook")314a8dc728d0 ("security: Align inode_setattr hook definition with EVM") 779cb1947e27 ("evm: Align evm_inode_post_setxattr() definition with LSM infrastructure") 2b6a4054f8c2 ("evm: Align evm_inode_setxattr() definition with LSM infrastructure") 784111d0093e ("evm: Align evm_inode_post_setattr() definition with LSM infrastructure") fec5f85e468d ("ima: Align ima_post_read_file() definition with LSM infrastructure") 526864dd2f60 ("ima: Align ima_inode_removexattr() definition with LSM infrastructure")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 9a95c5bfbf02a0a7f5983280fe284a0ff0836c34 Mon Sep 17 00:00:00 2001
From: GUO Zihua <[email protected]>
Date: Tue, 7 May 2024 01:25:41 +0000
Subject: [PATCH] ima: Avoid blocking in RCU read-side critical section
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+0x65/0xcaCommit 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.
include/linux/lsm_hook_defs.h +1 -1
@@ -413,7 +413,7 @@ LSM_HOOK(void, LSM_RET_VOID, key_post_create_or_update, struct key *keyring,#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)
include/linux/security.h +3 -2
@@ -2048,7 +2048,8 @@ static inline void security_key_post_create_or_update(struct key *keyring,#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);
@@ -2056,7 +2057,7 @@ void security_audit_rule_free(void *lsmrule);#else static inline int security_audit_rule_init (u32 field,u32 op,char *rulestr, -void **lsmrule) +void **lsmrule,gfp_t gfp) {return 0 ; }
kernel/auditfilter.c +3 -2
@@ -529,7 +529,8 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, 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 ) {
@@ -799,7 +800,7 @@ static inline int audit_dupe_lsm_field(struct audit_field *df,/* 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 ) {
security/apparmor/audit.c +3 -3
@@ -217,7 +217,7 @@ 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;
@@ -230,14 +230,14 @@ int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)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);
security/apparmor/include/audit.h +1 -1
@@ -200,7 +200,7 @@ static inline int complain_error(int error) }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);
security/integrity/ima/ima.h +1 -1
@@ -546,7 +546,7 @@ static inline void ima_free_modsig(struct modsig *modsig)#else static inline int ima_filter_rule_init (u32 field,u32 op,char *rulestr, -void **lsmrule) +void **lsmrule,gfp_t gfp) {return -EINVAL ; }
security/integrity/ima/ima_policy.c +9 -6
@@ -401,7 +401,8 @@ static void ima_free_rule(struct ima_rule_entry *entry)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;
@@ -410,7 +411,7 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)* 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 ;
@@ -425,7 +426,8 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)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);
@@ -438,7 +440,7 @@ static int ima_lsm_update_rule(struct ima_rule_entry *entry)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 ;
@@ -664,7 +666,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, }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;
@@ -1140,7 +1142,8 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry, 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);
security/security.c +4 -2
@@ -5332,15 +5332,17 @@ void security_key_post_create_or_update(struct key *keyring, struct key *key,* @op: rule operator * @rulestr: rule context * @lsmrule: receive buffer for audit rule struct +* @gfp: GFP flag used for kmalloc * * Allocate and initialize an LSM audit rule structure. * * Return: Return 0 if @lsmrule has been successfully set, -EINVAL in case of * an invalid rule. */ -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, field, op, rulestr, lsmrule); +return call_int_hook (audit_rule_init, field, op, rulestr, lsmrule, gfp); }/**
security/selinux/include/audit.h +3 -1
@@ -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.
security/selinux/ss/services.c +3 -2
@@ -3507,7 +3507,8 @@ 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;
@@ -3548,7 +3549,7 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)return -EINVAL ; } - tmprule =kzalloc (sizeof (struct selinux_audit_rule ),GFP_KERNEL ); + tmprule =kzalloc (sizeof (struct selinux_audit_rule ), gfp);if (!tmprule)return -ENOMEM ;context_init (&tmprule->au_ctxt);
security/smack/smack_lsm.c +3 -1
@@ -4693,11 +4693,13 @@ static int smack_post_notification(const struct cred *w_cred,* @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;