+Cc IMA maintainers On Fri, Jun 26 2026, Baoquan He wrote:
> Add kexec ML to CC. > > On Fri, Jun 26, 2026 at 7:46 AM Tao Liu <[email protected]> wrote: >> >> Kindly ping, any comments? >> >> Thanks, >> Tao Liu >> >> On Fri, May 29, 2026 at 3:35 PM Tao Liu <[email protected]> wrote: >> > >> > A NULL pointer reference issue is noticed in riscv's machine_kexec_prepare, >> > where image->segment[i].buf might be NULL and copied unchecked. >> > >> > The NULL buf comes from security/integrity/ima/ima_kexec.c: >> > ima_add_kexec_buffer(), where kbuf is added by kexec_add_buffer(), >> > but kbuf.buffer is NULL. >> > >> > Fix this by simply adding a check before copy. >> > >> > Signed-off-by: Tao Liu <[email protected]> >> > --- >> > arch/riscv/kernel/machine_kexec.c | 3 +++ >> > 1 file changed, 3 insertions(+) >> > >> > diff --git a/arch/riscv/kernel/machine_kexec.c >> > b/arch/riscv/kernel/machine_kexec.c >> > index 2306ce3e5f22..d81d576f9cb5 100644 >> > --- a/arch/riscv/kernel/machine_kexec.c >> > +++ b/arch/riscv/kernel/machine_kexec.c >> > @@ -41,6 +41,9 @@ machine_kexec_prepare(struct kimage *image) >> > if (image->segment[i].memsz <= sizeof(fdt)) >> > continue; >> > >> > + if (image->segment[i].buf == NULL) >> > + continue; >> > + > > This is a good fix, maybe we can add code comments to explain it as > below, just for reference. > > /* > * Some segments (e.g. IMA) reserve space but have no buffer > * loaded yet. Skip them as they cannot contain an FDT. > */ > And is there any other place where the similar issue exists? e.g on LoongArch? > > Other than above concerns, this patch looks good to me: > > Acked-by: Baoquan He <[email protected]> Yeah, the patch LGTM to me too. Acked-by: Pratyush Yadav <[email protected]> Although I think IMA can make this a bit easier to understand. First, in ima_add_kexec_buffer() it should set kbuf.buffer to NULL and kbuf.bufsz to 0 explicitly instead of using kexec_buffer and kexec_buffer_size which are initialized to NULL and 0, but never updated. Using the variables here adds an extra level of indirection. Also, perhaps we should add a comment in ima_add_kexec_buffer() about how this all works, since where the IMA buffer lives and where it gets updated it fairly complicated and took me some time to piece together. -- Regards, Pratyush Yadav
