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.
>
> 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;
>
