Commit 06b4e09a authored by Kees Cook's avatar Kees Cook
Browse files

pstore/ram: Set freed addresses to NULL 



For good measure, set all the freed addresses to NULL when managing
przs.

Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-and-tested-by: default avatarGuilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://lore.kernel.org/r/20221011200112.731334-5-keescook@chromium.org
parent 8bd4da0f

fs/pstore/ram.c

+8 −5
Original line number Diff line number Diff line
@@ -453,25 +453,27 @@ static void ramoops_free_przs(struct ramoops_context *cxt) 
	int i;



	/* Free pmsg PRZ */

	persistent_ram_free(cxt->mprz);

	persistent_ram_free(&cxt->mprz);



	/* Free console PRZ */

	persistent_ram_free(cxt->cprz);

	persistent_ram_free(&cxt->cprz);



	/* Free dump PRZs */

	if (cxt->dprzs) {

		for (i = 0; i < cxt->max_dump_cnt; i++)

			persistent_ram_free(cxt->dprzs[i]);

			persistent_ram_free(&cxt->dprzs[i]);



		kfree(cxt->dprzs);

		cxt->dprzs = NULL;

		cxt->max_dump_cnt = 0;

	}



	/* Free ftrace PRZs */

	if (cxt->fprzs) {

		for (i = 0; i < cxt->max_ftrace_cnt; i++)

			persistent_ram_free(cxt->fprzs[i]);

			persistent_ram_free(&cxt->fprzs[i]);

		kfree(cxt->fprzs);

		cxt->fprzs = NULL;

		cxt->max_ftrace_cnt = 0;

	}

}
@@ -555,9 +557,10 @@ static int ramoops_init_przs(const char *name, 


			while (i > 0) {

				i--;

				persistent_ram_free(prz_ar[i]);

				persistent_ram_free(&prz_ar[i]);

			}

			kfree(prz_ar);

			prz_ar = NULL;

			goto fail;

		}

		*paddr += zone_sz;

fs/pstore/ram_core.c

+9 −2
Original line number Diff line number Diff line
@@ -544,8 +544,14 @@ static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig, 
	return 0;

}



void persistent_ram_free(struct persistent_ram_zone *prz)

void persistent_ram_free(struct persistent_ram_zone **_prz)

{

	struct persistent_ram_zone *prz;



	if (!_prz)

		return;



	prz = *_prz;

	if (!prz)

		return;
@@ -569,6 +575,7 @@ void persistent_ram_free(struct persistent_ram_zone *prz) 
	persistent_ram_free_old(prz);

	kfree(prz->label);

	kfree(prz);

	*_prz = NULL;

}



struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
@@ -605,6 +612,6 @@ struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size, 


	return prz;

err:

	persistent_ram_free(prz);

	persistent_ram_free(&prz);

	return ERR_PTR(ret);

}

fs/pstore/ram_internal.h

+1 −1
Original line number Diff line number Diff line
@@ -82,7 +82,7 @@ struct persistent_ram_zone { 
struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,

			u32 sig, struct persistent_ram_ecc_info *ecc_info,

			unsigned int memtype, u32 flags, char *label);

void persistent_ram_free(struct persistent_ram_zone *prz);

void persistent_ram_free(struct persistent_ram_zone **_prz);

void persistent_ram_zap(struct persistent_ram_zone *prz);



int persistent_ram_write(struct persistent_ram_zone *prz, const void *s,