[PATCH 6.19 008/220] crash_dump: dont log dm-crypt key bytes in read_key_from_user_keying

Greg Kroah-Hartman
2026-03-23T13:51:01Z

From: Thorsten Blum <thorsten.blum@linux.dev>

commit 36f46b0e36892eba08978eef7502ff3c94ddba77 upstream.

When debug logging is enabled, read_key_from_user_keying() logs the first
8 bytes of the key payload and partially exposes the dm-crypt key. Stop
logging any key bytes.

Link: https://lkml.kernel.org/r/20260227230008.858641-2-thorsten.blum@linux.dev
Fixes: 479e58549b0f ("crash_dump: store dm crypt keys in kdump reserved memory")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Cc: Baoquan He <bhe@redhat.com>
Cc: Coiby Xu <coxu@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/crash_dump_dm_crypt.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/crash_dump_dm_crypt.c
+++ b/kernel/crash_dump_dm_crypt.c
@@ -168,8 +168,8 @@ static int read_key_from_user_keying(str

memcpy(dm_key->data, ukp->data, ukp->datalen);
dm_key->key_size = ukp->datalen;
- kexec_dprintk("Get dm crypt key (size=%u) %s: %8ph\n", dm_key->key_size,
- dm_key->key_desc, dm_key->data);
+ kexec_dprintk("Get dm crypt key (size=%u) %s\n", dm_key->key_size,
+ dm_key->key_desc);

out:
up_read(&key->sem);