[PATCH v3 5/5] lib: utils/irqchip: plic: Ensure no out-of-bound access in context save/restore helpers
Anup Patel
anup at brainfault.org
Sun Dec 11 04:06:03 PST 2022
On Sun, Dec 11, 2022 at 12:25 PM Bin Meng <bmeng at tinylab.org> wrote:
>
> Currently the context save/restore helpers writes/reads the provided
> array using an index whose maximum value is determined by PLIC, which
> potentially may disagree with the caller to these helpers.
>
> Add a parameter to ask the caller to provide the size limit of the
> array to ensure no out-of-bound access happens.
>
> Signed-off-by: Bin Meng <bmeng at tinylab.org>
Looks good to me.
Reviewed-by: Anup Patel <anup at brainfault.org>
Regards,
Anup
>
> ---
>
> Changes in v3:
> - move the size limit check to plic_context_save/restore
>
> Changes in v2:
> - new patch: lib: utils/irqchip: plic: Ensure no out-of-bound access in context save/restore helpers
>
> include/sbi_utils/irqchip/fdt_irqchip_plic.h | 5 +++--
> include/sbi_utils/irqchip/plic.h | 4 ++--
> lib/utils/irqchip/fdt_irqchip_plic.c | 9 +++++----
> lib/utils/irqchip/plic.c | 14 ++++++++++----
> platform/generic/allwinner/sun20i-d1.c | 5 +++--
> 5 files changed, 23 insertions(+), 14 deletions(-)
>
> diff --git a/include/sbi_utils/irqchip/fdt_irqchip_plic.h b/include/sbi_utils/irqchip/fdt_irqchip_plic.h
> index d5b1c60..df645dd 100644
> --- a/include/sbi_utils/irqchip/fdt_irqchip_plic.h
> +++ b/include/sbi_utils/irqchip/fdt_irqchip_plic.h
> @@ -23,9 +23,10 @@ void fdt_plic_priority_save(u8 *priority, u32 num);
> */
> void fdt_plic_priority_restore(const u8 *priority, u32 num);
>
> -void fdt_plic_context_save(bool smode, u32 *enable, u32 *threshold);
> +void fdt_plic_context_save(bool smode, u32 *enable, u32 *threshold, u32 num);
>
> -void fdt_plic_context_restore(bool smode, const u32 *enable, u32 threshold);
> +void fdt_plic_context_restore(bool smode, const u32 *enable, u32 threshold,
> + u32 num);
>
> void thead_plic_restore(void);
>
> diff --git a/include/sbi_utils/irqchip/plic.h b/include/sbi_utils/irqchip/plic.h
> index 38704a1..112a714 100644
> --- a/include/sbi_utils/irqchip/plic.h
> +++ b/include/sbi_utils/irqchip/plic.h
> @@ -24,10 +24,10 @@ void plic_priority_restore(const struct plic_data *plic, const u8 *priority,
> u32 num);
>
> void plic_context_save(const struct plic_data *plic, int context_id,
> - u32 *enable, u32 *threshold);
> + u32 *enable, u32 *threshold, u32 num);
>
> void plic_context_restore(const struct plic_data *plic, int context_id,
> - const u32 *enable, u32 threshold);
> + const u32 *enable, u32 threshold, u32 num);
>
> int plic_context_init(const struct plic_data *plic, int context_id,
> bool enable, u32 threshold);
> diff --git a/lib/utils/irqchip/fdt_irqchip_plic.c b/lib/utils/irqchip/fdt_irqchip_plic.c
> index 7d76c5b..c54f45c 100644
> --- a/lib/utils/irqchip/fdt_irqchip_plic.c
> +++ b/lib/utils/irqchip/fdt_irqchip_plic.c
> @@ -38,22 +38,23 @@ void fdt_plic_priority_restore(const u8 *priority, u32 num)
> plic_priority_restore(plic, priority, num);
> }
>
> -void fdt_plic_context_save(bool smode, u32 *enable, u32 *threshold)
> +void fdt_plic_context_save(bool smode, u32 *enable, u32 *threshold, u32 num)
> {
> u32 hartid = current_hartid();
>
> plic_context_save(plic_hartid2data[hartid],
> plic_hartid2context[hartid][smode],
> - enable, threshold);
> + enable, threshold, num);
> }
>
> -void fdt_plic_context_restore(bool smode, const u32 *enable, u32 threshold)
> +void fdt_plic_context_restore(bool smode, const u32 *enable, u32 threshold,
> + u32 num)
> {
> u32 hartid = current_hartid();
>
> plic_context_restore(plic_hartid2data[hartid],
> plic_hartid2context[hartid][smode],
> - enable, threshold);
> + enable, threshold, num);
> }
>
> static int irqchip_plic_warm_init(void)
> diff --git a/lib/utils/irqchip/plic.c b/lib/utils/irqchip/plic.c
> index b152bb7..8089a0b 100644
> --- a/lib/utils/irqchip/plic.c
> +++ b/lib/utils/irqchip/plic.c
> @@ -98,22 +98,28 @@ static void plic_set_ie(const struct plic_data *plic, u32 cntxid,
> }
>
> void plic_context_save(const struct plic_data *plic, int context_id,
> - u32 *enable, u32 *threshold)
> + u32 *enable, u32 *threshold, u32 num)
> {
> u32 ie_words = plic->num_src / 32 + 1;
>
> - for (u32 i = 0; i < ie_words; i++)
> + if (num > ie_words)
> + num = ie_words;
> +
> + for (u32 i = 0; i < num; i++)
> enable[i] = plic_get_ie(plic, context_id, i);
>
> *threshold = plic_get_thresh(plic, context_id);
> }
>
> void plic_context_restore(const struct plic_data *plic, int context_id,
> - const u32 *enable, u32 threshold)
> + const u32 *enable, u32 threshold, u32 num)
> {
> u32 ie_words = plic->num_src / 32 + 1;
>
> - for (u32 i = 0; i < ie_words; i++)
> + if (num > ie_words)
> + num = ie_words;
> +
> + for (u32 i = 0; i < num; i++)
> plic_set_ie(plic, context_id, i, enable[i]);
>
> plic_set_thresh(plic, context_id, threshold);
> diff --git a/platform/generic/allwinner/sun20i-d1.c b/platform/generic/allwinner/sun20i-d1.c
> index 1f27575..1da9e5b 100644
> --- a/platform/generic/allwinner/sun20i-d1.c
> +++ b/platform/generic/allwinner/sun20i-d1.c
> @@ -78,7 +78,7 @@ static u32 plic_threshold;
>
> static void sun20i_d1_plic_save(void)
> {
> - fdt_plic_context_save(true, plic_sie, &plic_threshold);
> + fdt_plic_context_save(true, plic_sie, &plic_threshold, PLIC_IE_WORDS);
> fdt_plic_priority_save(plic_priority, PLIC_SOURCES);
> }
>
> @@ -86,7 +86,8 @@ static void sun20i_d1_plic_restore(void)
> {
> thead_plic_restore();
> fdt_plic_priority_restore(plic_priority, PLIC_SOURCES);
> - fdt_plic_context_restore(true, plic_sie, plic_threshold);
> + fdt_plic_context_restore(true, plic_sie, plic_threshold,
> + PLIC_IE_WORDS);
> }
>
> /*
> --
> 2.34.1
>
>
> --
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