On 3/20/2025 6:06 AM, Mimi Zohar wrote:
On Thu, 2025-03-20 at 09:51 +0800, Baoquan He wrote:
diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
index 8567619889d1..45170e283272 100644
--- a/security/integrity/ima/ima_kexec.c
+++ b/security/integrity/ima/ima_kexec.c
@@ -15,6 +15,48 @@
#include "ima.h"
#ifdef CONFIG_IMA_KEXEC
+static struct seq_file ima_kexec_file;
+
+static void ima_reset_kexec_file(struct seq_file *sf)
+{
+ sf->buf = NULL;
+ sf->size = 0;
+ sf->read_pos = 0;
+ sf->count = 0;
+}
+
+static void ima_free_kexec_file_buf(struct seq_file *sf)
+{
+ vfree(sf->buf);
+ ima_reset_kexec_file(sf);
+}
+
+static int ima_alloc_kexec_file_buf(size_t segment_size)
+{
+ /*
+ * kexec 'load' may be called multiple times.
+ * Free and realloc the buffer only if the segment_size is
+ * changed from the previous kexec 'load' call.
+ */
+ if (ima_kexec_file.buf && ima_kexec_file.size == segment_size)
+ goto out;
The call to ima_reset_kexec_file() in ima_add_kexec_buffer() resets
ima_kexec_file.buf() hiding the fact that the above test always fails and falls
through. As a result, 'buf' is always being re-allocated.
Hi Steven,
[Reiterating the comment in the "ima: kexec: move IMA log copy from kexec load
to execute" thread, here, for completeness.]
Instead of adding and then removing the ima_reset_kexec_file() call from
ima_add_kexec_buffer(), defer adding the segment size test to when it is
actually possible for the segment size to change. Please make the segment size
test as a separate patch.
ima_reset_kexec_file() will then only be called by ima_free_kexec_file_buf().
Inline the ima_reset_kexec_file() code in ima_free_kexec_file_buf().
thanks,
Mimi
Hi Mimi,
I will update in next version.
Thanks,
Steven
