Merge tag 'v5.5-rc5' into locking/kcsan, to resolve conflict

Signed-off-by: Ingo Molnar <mingo@kernel.org>

6 files changed, 72 insertions, 57 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 4983940cbdca..6f63ae7a370c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -907,7 +907,8 @@ static const int caller_saved[CALLER_SAVED_REGS] = {
 	BPF_REG_0, BPF_REG_1, BPF_REG_2, BPF_REG_3, BPF_REG_4, BPF_REG_5
 };
 
-static void __mark_reg_not_init(struct bpf_reg_state *reg);
+static void __mark_reg_not_init(const struct bpf_verifier_env *env,
+				struct bpf_reg_state *reg);
 
 /* Mark the unknown part of a register (variable offset or scalar value) as
  * known to have the value @imm.
@@ -945,7 +946,7 @@ static void mark_reg_known_zero(struct bpf_verifier_env *env,
 		verbose(env, "mark_reg_known_zero(regs, %u)\n", regno);
 		/* Something bad happened, let's kill all regs */
 		for (regno = 0; regno < MAX_BPF_REG; regno++)
-			__mark_reg_not_init(regs + regno);
+			__mark_reg_not_init(env, regs + regno);
 		return;
 	}
 	__mark_reg_known_zero(regs + regno);
@@ -1054,7 +1055,8 @@ static void __mark_reg_unbounded(struct bpf_reg_state *reg)
 }
 
 /* Mark a register as having a completely unknown (scalar) value. */
-static void __mark_reg_unknown(struct bpf_reg_state *reg)
+static void __mark_reg_unknown(const struct bpf_verifier_env *env,
+			       struct bpf_reg_state *reg)
 {
 	/*
 	 * Clear type, id, off, and union(map_ptr, range) and
@@ -1064,6 +1066,8 @@ static void __mark_reg_unknown(struct bpf_reg_state *reg)
 	reg->type = SCALAR_VALUE;
 	reg->var_off = tnum_unknown;
 	reg->frameno = 0;
+	reg->precise = env->subprog_cnt > 1 || !env->allow_ptr_leaks ?
+		       true : false;
 	__mark_reg_unbounded(reg);
 }
 
@@ -1074,19 +1078,16 @@ static void mark_reg_unknown(struct bpf_verifier_env *env,
 		verbose(env, "mark_reg_unknown(regs, %u)\n", regno);
 		/* Something bad happened, let's kill all regs except FP */
 		for (regno = 0; regno < BPF_REG_FP; regno++)
-			__mark_reg_not_init(regs + regno);
+			__mark_reg_not_init(env, regs + regno);
 		return;
 	}
-	regs += regno;
-	__mark_reg_unknown(regs);
-	/* constant backtracking is enabled for root without bpf2bpf calls */
-	regs->precise = env->subprog_cnt > 1 || !env->allow_ptr_leaks ?
-			true : false;
+	__mark_reg_unknown(env, regs + regno);
 }
 
-static void __mark_reg_not_init(struct bpf_reg_state *reg)
+static void __mark_reg_not_init(const struct bpf_verifier_env *env,
+				struct bpf_reg_state *reg)
 {
-	__mark_reg_unknown(reg);
+	__mark_reg_unknown(env, reg);
 	reg->type = NOT_INIT;
 }
 
@@ -1097,10 +1098,10 @@ static void mark_reg_not_init(struct bpf_verifier_env *env,
 		verbose(env, "mark_reg_not_init(regs, %u)\n", regno);
 		/* Something bad happened, let's kill all regs except FP */
 		for (regno = 0; regno < BPF_REG_FP; regno++)
-			__mark_reg_not_init(regs + regno);
+			__mark_reg_not_init(env, regs + regno);
 		return;
 	}
-	__mark_reg_not_init(regs + regno);
+	__mark_reg_not_init(env, regs + regno);
 }
 
 #define DEF_NOT_SUBREG	(0)
@@ -3234,7 +3235,7 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
 		}
 		if (state->stack[spi].slot_type[0] == STACK_SPILL &&
 		    state->stack[spi].spilled_ptr.type == SCALAR_VALUE) {
-			__mark_reg_unknown(&state->stack[spi].spilled_ptr);
+			__mark_reg_unknown(env, &state->stack[spi].spilled_ptr);
 			for (j = 0; j < BPF_REG_SIZE; j++)
 				state->stack[spi].slot_type[j] = STACK_MISC;
 			goto mark;
@@ -3892,7 +3893,7 @@ static void __clear_all_pkt_pointers(struct bpf_verifier_env *env,
 		if (!reg)
 			continue;
 		if (reg_is_pkt_pointer_any(reg))
-			__mark_reg_unknown(reg);
+			__mark_reg_unknown(env, reg);
 	}
 }
 
@@ -3920,7 +3921,7 @@ static void release_reg_references(struct bpf_verifier_env *env,
 		if (!reg)
 			continue;
 		if (reg->ref_obj_id == ref_obj_id)
-			__mark_reg_unknown(reg);
+			__mark_reg_unknown(env, reg);
 	}
 }
 
@@ -4582,7 +4583,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 		/* Taint dst register if offset had invalid bounds derived from
 		 * e.g. dead branches.
 		 */
-		__mark_reg_unknown(dst_reg);
+		__mark_reg_unknown(env, dst_reg);
 		return 0;
 	}
 
@@ -4834,13 +4835,13 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 		/* Taint dst register if offset had invalid bounds derived from
 		 * e.g. dead branches.
 		 */
-		__mark_reg_unknown(dst_reg);
+		__mark_reg_unknown(env, dst_reg);
 		return 0;
 	}
 
 	if (!src_known &&
 	    opcode != BPF_ADD && opcode != BPF_SUB && opcode != BPF_AND) {
-		__mark_reg_unknown(dst_reg);
+		__mark_reg_unknown(env, dst_reg);
 		return 0;
 	}
 
@@ -6982,7 +6983,7 @@ static void clean_func_state(struct bpf_verifier_env *env,
 			/* since the register is unused, clear its state
 			 * to make further comparison simpler
 			 */
-			__mark_reg_not_init(&st->regs[i]);
+			__mark_reg_not_init(env, &st->regs[i]);
 	}
 
 	for (i = 0; i < st->allocated_stack / BPF_REG_SIZE; i++) {
@@ -6990,7 +6991,7 @@ static void clean_func_state(struct bpf_verifier_env *env,
 		/* liveness must not touch this stack slot anymore */
 		st->stack[i].spilled_ptr.live |= REG_LIVE_DONE;
 		if (!(live & REG_LIVE_READ)) {
-			__mark_reg_not_init(&st->stack[i].spilled_ptr);
+			__mark_reg_not_init(env, &st->stack[i].spilled_ptr);
 			for (j = 0; j < BPF_REG_SIZE; j++)
 				st->stack[i].slot_type[j] = STACK_INVALID;
 		}
diff --git a/kernel/cred.c b/kernel/cred.c
index c0a4c12d38b2..9ed51b70ed80 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -223,7 +223,7 @@ struct cred *cred_alloc_blank(void)
 	new->magic = CRED_MAGIC;
 #endif
 
-	if (security_cred_alloc_blank(new, GFP_KERNEL) < 0)
+	if (security_cred_alloc_blank(new, GFP_KERNEL_ACCOUNT) < 0)
 		goto error;
 
 	return new;
@@ -282,7 +282,7 @@ struct cred *prepare_creds(void)
 	new->security = NULL;
 #endif
 
-	if (security_prepare_creds(new, old, GFP_KERNEL) < 0)
+	if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0)
 		goto error;
 	validate_creds(new);
 	return new;
@@ -715,7 +715,7 @@ struct cred *prepare_kernel_cred(struct task_struct *daemon)
 #ifdef CONFIG_SECURITY
 	new->security = NULL;
 #endif
-	if (security_prepare_creds(new, old, GFP_KERNEL) < 0)
+	if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0)
 		goto error;
 
 	put_cred(old);
diff --git a/kernel/exit.c b/kernel/exit.c
index bcbd59888e67..2833ffb0c211 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -517,10 +517,6 @@ static struct task_struct *find_child_reaper(struct task_struct *father,
 	}
 
 	write_unlock_irq(&tasklist_lock);
-	if (unlikely(pid_ns == &init_pid_ns)) {
-		panic("Attempted to kill init! exitcode=0x%08x\n",
-			father->signal->group_exit_code ?: father->exit_code);
-	}
 
 	list_for_each_entry_safe(p, n, dead, ptrace_entry) {
 		list_del_init(&p->ptrace_entry);
@@ -766,6 +762,14 @@ void __noreturn do_exit(long code)
 	acct_update_integrals(tsk);
 	group_dead = atomic_dec_and_test(&tsk->signal->live);
 	if (group_dead) {
+		/*
+		 * If the last thread of global init has exited, panic
+		 * immediately to get a useable coredump.
+		 */
+		if (unlikely(is_global_init(tsk)))
+			panic("Attempted to kill init! exitcode=0x%08x\n",
+				tsk->signal->group_exit_code ?: (int)code);
+
 #ifdef CONFIG_POSIX_TIMERS
 		hrtimer_cancel(&tsk->signal->real_timer);
 		exit_itimers(tsk->signal);
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 12d2227e5786..b6ea3dcb57bf 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -1026,6 +1026,13 @@ static long seccomp_notify_recv(struct seccomp_filter *filter,
 	struct seccomp_notif unotif;
 	ssize_t ret;
 
+	/* Verify that we're not given garbage to keep struct extensible. */
+	ret = check_zeroed_user(buf, sizeof(unotif));
+	if (ret < 0)
+		return ret;
+	if (!ret)
+		return -EINVAL;
+
 	memset(&unotif, 0, sizeof(unotif));
 
 	ret = down_interruptible(&filter->notif->request);
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 13a0f2e6ebc2..e2ac0e37c4ae 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -554,25 +554,33 @@ static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
 static struct taskstats *taskstats_tgid_alloc(struct task_struct *tsk)
 {
 	struct signal_struct *sig = tsk->signal;
-	struct taskstats *stats;
+	struct taskstats *stats_new, *stats;
 
-	if (sig->stats || thread_group_empty(tsk))
-		goto ret;
+	/* Pairs with smp_store_release() below. */
+	stats = smp_load_acquire(&sig->stats);
+	if (stats || thread_group_empty(tsk))
+		return stats;
 
 	/* No problem if kmem_cache_zalloc() fails */
-	stats = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL);
+	stats_new = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL);
 
 	spin_lock_irq(&tsk->sighand->siglock);
-	if (!sig->stats) {
-		sig->stats = stats;
-		stats = NULL;
+	stats = sig->stats;
+	if (!stats) {
+		/*
+		 * Pairs with smp_store_release() above and order the
+		 * kmem_cache_zalloc().
+		 */
+		smp_store_release(&sig->stats, stats_new);
+		stats = stats_new;
+		stats_new = NULL;
 	}
 	spin_unlock_irq(&tsk->sighand->siglock);
 
-	if (stats)
-		kmem_cache_free(taskstats_cache, stats);
-ret:
-	return sig->stats;
+	if (stats_new)
+		kmem_cache_free(taskstats_cache, stats_new);
+
+	return stats;
 }
 
 /* Send pid data out on exit */
diff --git a/kernel/time/posix-clock.c b/kernel/time/posix-clock.c
index ec960bb939fd..200fb2d3be99 100644
--- a/kernel/time/posix-clock.c
+++ b/kernel/time/posix-clock.c
@@ -14,8 +14,6 @@
 
 #include "posix-timers.h"
 
-static void delete_clock(struct kref *kref);
-
 /*
  * Returns NULL if the posix_clock instance attached to 'fp' is old and stale.
  */
@@ -125,7 +123,7 @@ static int posix_clock_open(struct inode *inode, struct file *fp)
 		err = 0;
 
 	if (!err) {
-		kref_get(&clk->kref);
+		get_device(clk->dev);
 		fp->private_data = clk;
 	}
 out:
@@ -141,7 +139,7 @@ static int posix_clock_release(struct inode *inode, struct file *fp)
 	if (clk->ops.release)
 		err = clk->ops.release(clk);
 
-	kref_put(&clk->kref, delete_clock);
+	put_device(clk->dev);
 
 	fp->private_data = NULL;
 
@@ -161,38 +159,35 @@ static const struct file_operations posix_clock_file_operations = {
 #endif
 };
 
-int posix_clock_register(struct posix_clock *clk, dev_t devid)
+int posix_clock_register(struct posix_clock *clk, struct device *dev)
 {
 	int err;
 
-	kref_init(&clk->kref);
 	init_rwsem(&clk->rwsem);
 
 	cdev_init(&clk->cdev, &posix_clock_file_operations);
+	err = cdev_device_add(&clk->cdev, dev);
+	if (err) {
+		pr_err("%s unable to add device %d:%d\n",
+			dev_name(dev), MAJOR(dev->devt), MINOR(dev->devt));
+		return err;
+	}
 	clk->cdev.owner = clk->ops.owner;
-	err = cdev_add(&clk->cdev, devid, 1);
+	clk->dev = dev;
 
-	return err;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(posix_clock_register);
 
-static void delete_clock(struct kref *kref)
-{
-	struct posix_clock *clk = container_of(kref, struct posix_clock, kref);
-
-	if (clk->release)
-		clk->release(clk);
-}
-
 void posix_clock_unregister(struct posix_clock *clk)
 {
-	cdev_del(&clk->cdev);
+	cdev_device_del(&clk->cdev, clk->dev);
 
 	down_write(&clk->rwsem);
 	clk->zombie = true;
 	up_write(&clk->rwsem);
 
-	kref_put(&clk->kref, delete_clock);
+	put_device(clk->dev);
 }
 EXPORT_SYMBOL_GPL(posix_clock_unregister);