crash_dump: don't log dm-crypt key bytes in read_key_from_user_keying

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>

diff --git a/kernel/crash_dump_dm_crypt.c b/kernel/crash_dump_dm_crypt.c
index 1f4067fbdb9438dba91be0b127a4af1c02906884..a20d4097744aeeaddfcf7b378ea8bfe6d4064ded 100644 (file)
--- 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(struct dm_crypt_key *dm_key)
 
        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);