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Commit 5a18c531 authored by Jerome Marchand's avatar Jerome Marchand Committed by Greg Kroah-Hartman
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staging: zram: prevent accessing an unallocated table when init fails early 



When the allocation of zram->table fails, we set zram->disksize to zero
to prevent accessing the unallocated table entries during cleanup.
However, we currently don't take this precaution when the initialization
fails earlier.

Signed-off-by: default avatarJerome Marchand <jmarchan@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 0900beae

drivers/staging/zram/zram_drv.c

+6 −5
Original line number Diff line number Diff line
@@ -651,24 +651,22 @@ int zram_init_device(struct zram *zram) 
	if (!zram->compress_workmem) {

		pr_err("Error allocating compressor working memory!\n");

		ret = -ENOMEM;

		goto fail;

		goto fail_no_table;

	}



	zram->compress_buffer = (void *)__get_free_pages(__GFP_ZERO, 1);

	if (!zram->compress_buffer) {

		pr_err("Error allocating compressor buffer space\n");

		ret = -ENOMEM;

		goto fail;

		goto fail_no_table;

	}



	num_pages = zram->disksize >> PAGE_SHIFT;

	zram->table = vzalloc(num_pages * sizeof(*zram->table));

	if (!zram->table) {

		pr_err("Error allocating zram address table\n");

		/* To prevent accessing table entries during cleanup */

		zram->disksize = 0;

		ret = -ENOMEM;

		goto fail;

		goto fail_no_table;

	}



	set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
@@ -689,6 +687,9 @@ int zram_init_device(struct zram *zram) 
	pr_debug("Initialization done!\n");

	return 0;



fail_no_table:

	/* To prevent accessing table entries during cleanup */

	zram->disksize = 0;

fail:

	__zram_reset_device(zram);

	up_write(&zram->init_lock);