diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c
index 8a1ff605ff2d..3994a217bde7 100644
--- a/kernel/kcsan/core.c
+++ b/kernel/kcsan/core.c
@@ -100,6 +100,9 @@ static atomic_long_t watchpoints[CONFIG_KCSAN_NUM_WATCHPOINTS + NUM_SLOTS-1];
  */
 static DEFINE_PER_CPU(long, kcsan_skip);
 
+/* For kcsan_prandom_u32_max(). */
+static DEFINE_PER_CPU(struct rnd_state, kcsan_rand_state);
+
 static __always_inline atomic_long_t *find_watchpoint(unsigned long addr,
 						      size_t size,
 						      bool expect_write,
@@ -271,11 +274,28 @@ should_watch(const volatile void *ptr, size_t size, int type, struct kcsan_ctx *
 	return true;
 }
 
+/*
+ * Returns a pseudo-random number in interval [0, ep_ro). See prandom_u32_max()
+ * for more details.
+ *
+ * The open-coded version here is using only safe primitives for all contexts
+ * where we can have KCSAN instrumentation. In particular, we cannot use
+ * prandom_u32() directly, as its tracepoint could cause recursion.
+ */
+static u32 kcsan_prandom_u32_max(u32 ep_ro)
+{
+	struct rnd_state *state = &get_cpu_var(kcsan_rand_state);
+	const u32 res = prandom_u32_state(state);
+
+	put_cpu_var(kcsan_rand_state);
+	return (u32)(((u64) res * ep_ro) >> 32);
+}
+
 static inline void reset_kcsan_skip(void)
 {
 	long skip_count = kcsan_skip_watch -
 			  (IS_ENABLED(CONFIG_KCSAN_SKIP_WATCH_RANDOMIZE) ?
-				   prandom_u32_max(kcsan_skip_watch) :
+				   kcsan_prandom_u32_max(kcsan_skip_watch) :
 				   0);
 	this_cpu_write(kcsan_skip, skip_count);
 }
@@ -285,16 +305,18 @@ static __always_inline bool kcsan_is_enabled(void)
 	return READ_ONCE(kcsan_enabled) && get_ctx()->disable_count == 0;
 }
 
-static inline unsigned int get_delay(int type)
+/* Introduce delay depending on context and configuration. */
+static void delay_access(int type)
 {
 	unsigned int delay = in_task() ? kcsan_udelay_task : kcsan_udelay_interrupt;
 	/* For certain access types, skew the random delay to be longer. */
 	unsigned int skew_delay_order =
 		(type & (KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_ASSERT)) ? 1 : 0;
 
-	return delay - (IS_ENABLED(CONFIG_KCSAN_DELAY_RANDOMIZE) ?
-				prandom_u32_max(delay >> skew_delay_order) :
-				0);
+	delay -= IS_ENABLED(CONFIG_KCSAN_DELAY_RANDOMIZE) ?
+			       kcsan_prandom_u32_max(delay >> skew_delay_order) :
+			       0;
+	udelay(delay);
 }
 
 void kcsan_save_irqtrace(struct task_struct *task)
@@ -476,7 +498,7 @@ kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type)
 	 * Delay this thread, to increase probability of observing a racy
 	 * conflicting access.
 	 */
-	udelay(get_delay(type));
+	delay_access(type);
 
 	/*
 	 * Re-read value, and check if it is as expected; if not, we infer a
@@ -620,6 +642,7 @@ void __init kcsan_init(void)
 	BUG_ON(!in_task());
 
 	kcsan_debugfs_init();
+	prandom_seed_full_state(&kcsan_rand_state);
 
 	/*
 	 * We are in the init task, and no other tasks should be running;