[PATCH 6.18 348/752] binder: don't use %pK through printk

Sasha Levin
2026-02-28T17:52:59Z

From: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

[ Upstream commit 56d21267663bad91e8b10121224ec46366a7937e ]

In the past %pK was preferable to %p as it would not leak raw pointer
values into the kernel log. Since commit ad67b74d2469 ("printk: hash
addresses printed with %p") the regular %p has been improved to avoid
this issue. Furthermore, restricted pointers ("%pK") were never meant
to be used through printk(). They can still unintentionally leak raw
pointers or acquire sleeping locks in atomic contexts.

Switch to the regular pointer formatting which is safer and
easier to reason about.

There are still a few users of %pK left, but these use it through
seq_file, for which its usage is safe.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Carlos Llamas <cmllamas@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260107-restricted-pointers-binder-v1-1-181018bf3812@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/android/binder.c | 2 +-
drivers/android/binder_alloc.c | 6 +++---
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 8e2989fb56a71..a6b3bfe0d9b81 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -4523,7 +4523,7 @@ static int binder_thread_write(struct binder_proc *proc,
}
}
binder_debug(BINDER_DEBUG_DEAD_BINDER,
- "%d:%d BC_DEAD_BINDER_DONE %016llx found %pK\n",
+ "%d:%d BC_DEAD_BINDER_DONE %016llx found %p\n",
proc->pid, thread->pid, (u64)cookie,
death);
if (death == NULL) {
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index 979c96b74cad3..d5ed64543bbf4 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -81,7 +81,7 @@ static void binder_insert_free_buffer(struct binder_alloc *alloc,
new_buffer_size = binder_alloc_buffer_size(alloc, new_buffer);

binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
- "%d: add free buffer, size %zd, at %pK\n",
+ "%d: add free buffer, size %zd, at %p\n",
alloc->pid, new_buffer_size, new_buffer);

while (*p) {
@@ -572,7 +572,7 @@ static struct binder_buffer *binder_alloc_new_buf_locked(
}

binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
- "%d: binder_alloc_buf size %zd got buffer %pK size %zd\n",
+ "%d: binder_alloc_buf size %zd got buffer %p size %zd\n",
alloc->pid, size, buffer, buffer_size);

/*
@@ -748,7 +748,7 @@ static void binder_free_buf_locked(struct binder_alloc *alloc,
ALIGN(buffer->extra_buffers_size, sizeof(void *));

binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
- "%d: binder_free_buf %pK size %zd buffer_size %zd\n",
+ "%d: binder_free_buf %p size %zd buffer_size %zd\n",
alloc->pid, buffer, size, buffer_size);

BUG_ON(buffer->free);
--
2.51.0