On Mon, Aug 31, 2026 at 09:24:07AM +0800, Jinjie Ruan wrote:
在 2026/8/30 13:59, Sourabh Jain 写道:
Hello Jinjie,
Coiby is handling this issue in the below patch series:
https://lore.kernel.org/all/[email protected]/
Since the above patch series is all about crash_load_dm_crypt_keys,
could you
please consider dropping this patch from your series and reviewing his
patch
instead?
Absolutely, happy to do so — I'll drop this patch and review Coiby's
series instead.
Hi Jinjie,
Thank you for agreeing to drop your patch and review mine instead!
Thanks,
Sourabh Jain
On 26/08/26 14:55, Jinjie Ruan wrote:
`keys_header` was freed in `build_keys_header()` without being reset
to NULL, and the error path in `crash_load_dm_crypt_keys()` freed it
unconditionally even when reused, leading to double-free or
use-after-free.
Add `free_keys_header()` to centralize freeing and NULL-setting.
Use it in `build_keys_header()` and only free in the error path when
the header was newly built (`!is_dm_key_reused`).
Cc: Andrew Morton <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Pasha Tatashin <[email protected]>
Cc: Pratyush Yadav <[email protected]>
Cc: Dave Young <[email protected]>
Cc: [email protected]
Fixes: e3a84be1ec2f ("arm64,ppc64le/kdump: pass dm-crypt keys to kdump
kernel")
Signed-off-by: Jinjie Ruan <[email protected]>
---
kernel/crash_dump_dm_crypt.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/kernel/crash_dump_dm_crypt.c b/kernel/crash_dump_dm_crypt.c
index c685497cd470..ed0960ff0987 100644
--- a/kernel/crash_dump_dm_crypt.c
+++ b/kernel/crash_dump_dm_crypt.c
@@ -363,15 +363,21 @@ static struct configfs_subsystem
config_keys_subsys = {
},
};
+static void free_keys_header(void)
+{
+ if (keys_header) {
+ kvfree(keys_header);
+ keys_header = NULL;
+ }
+}
+
static int build_keys_header(void)
{
struct config_item *item = NULL;
struct config_key *key;
int i, r;
- if (keys_header != NULL)
- kvfree(keys_header);
-
+ free_keys_header();
keys_header = kzalloc(get_keys_header_size(key_count), GFP_KERNEL);
if (!keys_header)
return -ENOMEM;
@@ -441,7 +447,8 @@ int crash_load_dm_crypt_keys(struct kimage *image)
r = kexec_add_buffer(&kbuf);
if (r) {
pr_err("Failed to call kexec_add_buffer, ret=%d\n", r);
- kvfree((void *)kbuf.buffer);
+ if (!is_dm_key_reused)
+ free_keys_header();
return r;
}
image->dm_crypt_keys_addr = kbuf.mem;
--
Best regards,
Coiby
