On Thu, May 26, 2022 at 4:38 PM Pasha Tatashin
<[email protected]> wrote:
>
> In some case initrd can be large. For example, it could be a netboot
> image loaded by u-root, that is kexec'ing into it.
>
> The maximum size of initrd is arbitrary set to 2G. Also, the limit is
> not very obvious because it is hidden behind a generic INT_MAX macro.
>
> Theoretically, we could make it LONG_MAX, but it is safer to keep it
> sane, and just increase it to 4G.
>
> Increase the size to 4G, and make it obvious by having a new macro
> that specifies the maximum file size supported by kexec_file_load()
> syscall: KEXEC_FILE_SIZE_MAX.
>
> Signed-off-by: Pasha Tatashin <[email protected]>
Should be instead:
Signed-off-by: Pasha Tatashin <[email protected]>
Thanks,
Pasha
> ---
> kernel/kexec_file.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index 8347fc158d2b..1be2227b33e6 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -31,6 +31,9 @@
>
> static int kexec_calculate_store_digests(struct kimage *image);
>
> +/* Maximum size in bytes for kernel/initrd files. */
> +#define KEXEC_FILE_SIZE_MAX (4UL << 30)
> +
> /*
> * Currently this is the only default function that is exported as some
> * architectures need it to do additional handlings.
> @@ -227,7 +230,8 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
> void *ldata;
>
> ret = kernel_read_file_from_fd(kernel_fd, 0, &image->kernel_buf,
> - INT_MAX, NULL, READING_KEXEC_IMAGE);
> + KEXEC_FILE_SIZE_MAX, NULL,
> + READING_KEXEC_IMAGE);
> if (ret < 0)
> return ret;
> image->kernel_buf_len = ret;
> @@ -247,7 +251,7 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
> /* It is possible that there no initramfs is being loaded */
> if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
> ret = kernel_read_file_from_fd(initrd_fd, 0, &image->initrd_buf,
> - INT_MAX, NULL,
> + KEXEC_FILE_SIZE_MAX, NULL,
> READING_KEXEC_INITRAMFS);
> if (ret < 0)
> goto out;
> --
> 2.36.1.124.g0e6072fb45-goog
>
On Thu, May 26, 2022 at 4:45 PM Pasha Tatashin
<[email protected]> wrote:
>
> On Thu, May 26, 2022 at 4:38 PM Pasha Tatashin
> <[email protected]> wrote:
> >
> > In some case initrd can be large. For example, it could be a netboot
> > image loaded by u-root, that is kexec'ing into it.
> >
> > The maximum size of initrd is arbitrary set to 2G. Also, the limit is
> > not very obvious because it is hidden behind a generic INT_MAX macro.
> >
> > Theoretically, we could make it LONG_MAX, but it is safer to keep it
> > sane, and just increase it to 4G.
> >
> > Increase the size to 4G, and make it obvious by having a new macro
> > that specifies the maximum file size supported by kexec_file_load()
> > syscall: KEXEC_FILE_SIZE_MAX.
It appears that since:
f7a4f689bca6072492626938aad6dd2f32c5bf97
fs/kernel_read_file: Remove redundant size argument
Introduced a change to kernel_read_file to limit the maximum file
internally from SIZE_MAX to INT_MAX.
Therefore, more changes will be needed. I will work on them and sent them in v2.
> >
> > Signed-off-by: Pasha Tatashin <[email protected]>
>
> Should be instead:
> Signed-off-by: Pasha Tatashin <[email protected]>
>
> Thanks,
> Pasha
>
> > ---
> > kernel/kexec_file.c | 8 ++++++--
> > 1 file changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> > index 8347fc158d2b..1be2227b33e6 100644
> > --- a/kernel/kexec_file.c
> > +++ b/kernel/kexec_file.c
> > @@ -31,6 +31,9 @@
> >
> > static int kexec_calculate_store_digests(struct kimage *image);
> >
> > +/* Maximum size in bytes for kernel/initrd files. */
> > +#define KEXEC_FILE_SIZE_MAX (4UL << 30)
Also, I will address 32-bit, with picking minimum between SIZE_MAX and
kexec max file.
Thanks,
Pasha