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27603a606f
Commit2aec377a29("dm table: remove dm_table_get_num_targets() wrapper") in linux-dm/for-next removed the function dm_table_get_num_targets() which is used by verity-loadpin. Access table->num_targets directly instead of using the defunct wrapper. Fixes:b6c1c5745c("dm: Add verity helpers for LoadPin") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220728085412.1.I242d21b378410eb6f9897a3160efb56e5608c59d@changeid
76 lines
1.5 KiB
C
76 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/list.h>
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#include <linux/kernel.h>
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#include <linux/dm-verity-loadpin.h>
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#include "dm.h"
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#include "dm-core.h"
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#include "dm-verity.h"
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#define DM_MSG_PREFIX "verity-loadpin"
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LIST_HEAD(dm_verity_loadpin_trusted_root_digests);
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static bool is_trusted_verity_target(struct dm_target *ti)
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{
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u8 *root_digest;
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unsigned int digest_size;
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struct dm_verity_loadpin_trusted_root_digest *trd;
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bool trusted = false;
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if (!dm_is_verity_target(ti))
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return false;
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if (dm_verity_get_root_digest(ti, &root_digest, &digest_size))
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return false;
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list_for_each_entry(trd, &dm_verity_loadpin_trusted_root_digests, node) {
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if ((trd->len == digest_size) &&
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!memcmp(trd->data, root_digest, digest_size)) {
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trusted = true;
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break;
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}
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}
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kfree(root_digest);
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return trusted;
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}
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/*
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* Determines whether the file system of a superblock is located on
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* a verity device that is trusted by LoadPin.
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*/
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bool dm_verity_loadpin_is_bdev_trusted(struct block_device *bdev)
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{
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struct mapped_device *md;
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struct dm_table *table;
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struct dm_target *ti;
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int srcu_idx;
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bool trusted = false;
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if (list_empty(&dm_verity_loadpin_trusted_root_digests))
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return false;
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md = dm_get_md(bdev->bd_dev);
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if (!md)
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return false;
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table = dm_get_live_table(md, &srcu_idx);
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if (table->num_targets != 1)
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goto out;
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ti = dm_table_get_target(table, 0);
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if (is_trusted_verity_target(ti))
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trusted = true;
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out:
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dm_put_live_table(md, srcu_idx);
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dm_put(md);
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return trusted;
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}
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