Re: [PATCH v5 3/3] arm64,ppc64le/kdump: pass dm-crypt keys to kdump kernel

[Coiby Xu]

On Thu, Apr 02, 2026 at 11:31:18PM -0700, Andrew Morton wrote:
> On Thu, 2 Apr 2026 16:24:14 +0530 Sourabh Jain <sourabhjain@xxxxxxxxxxxxx> wrote:
>
> > But while reading crash_load_dm_crypt_keys() I noticed a possibility of a
> > double free at the address pointed by `keys_header`:
> >
> > In crash_load_dm_crypt_keys()/crash_dump_dm_crypt.c
> >      snip...
> >
> >      kbuf.buffer = keys_header;
> >
> >      snip....
> >
> >      r = kexec_add_buffer(&kbuf);
> >      if (r) {
> >          pr_err("Failed to call kexec_add_buffer, ret=%d\n", r);
> >          kvfree((void *)kbuf.buffer);                           <---
> > First Free
> >          return r;
> >      }
> >
> > Since `keys_header` is not reset, the next call to build_keys_header()
> > will cause a double free at `keys_header`.
> >
> > static int build_keys_header(void)
> > {
> >
> >      snip...
> >
> >      if (keys_header != NULL)
> >          kvfree(keys_header);
> >
> >      snip...
> > }
> >
> > What do you think?
>
> It looks that way to me.

Thanks for confirming it! I'll send a patch after finishing the testing.

--
Best regards,
Coiby