6.18-stable review patch. If anyone has any objections, please let me know.
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From: Jarkko Sakkinen jarkko.sakkinen@opinsys.com
commit faf07e611dfa464b201223a7253e9dc5ee0f3c9e upstream.
tpm2_get_pcr_allocation() does not cap any upper limit for the number of banks. Cap the limit to eight banks so that out of bounds values coming from external I/O cause on only limited harm.
Cc: stable@vger.kernel.org # v5.10+ Fixes: bcfff8384f6c ("tpm: dynamically allocate the allocated_banks array") Tested-by: Lai Yi yi1.lai@linux.intel.com Reviewed-by: Jonathan McDowell noodles@meta.com Reviewed-by: Roberto Sassu roberto.sassu@huawei.com Signed-off-by: Jarkko Sakkinen jarkko.sakkinen@opinsys.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/char/tpm/tpm-chip.c | 1 - drivers/char/tpm/tpm1-cmd.c | 5 ----- drivers/char/tpm/tpm2-cmd.c | 8 +++----- include/linux/tpm.h | 8 +++++--- 4 files changed, 8 insertions(+), 14 deletions(-)
--- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -282,7 +282,6 @@ static void tpm_dev_release(struct devic
kfree(chip->work_space.context_buf); kfree(chip->work_space.session_buf); - kfree(chip->allocated_banks); #ifdef CONFIG_TCG_TPM2_HMAC kfree(chip->auth); #endif --- a/drivers/char/tpm/tpm1-cmd.c +++ b/drivers/char/tpm/tpm1-cmd.c @@ -799,11 +799,6 @@ int tpm1_pm_suspend(struct tpm_chip *chi */ int tpm1_get_pcr_allocation(struct tpm_chip *chip) { - chip->allocated_banks = kcalloc(1, sizeof(*chip->allocated_banks), - GFP_KERNEL); - if (!chip->allocated_banks) - return -ENOMEM; - chip->allocated_banks[0].alg_id = TPM_ALG_SHA1; chip->allocated_banks[0].digest_size = hash_digest_size[HASH_ALGO_SHA1]; chip->allocated_banks[0].crypto_id = HASH_ALGO_SHA1; --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -538,11 +538,9 @@ ssize_t tpm2_get_pcr_allocation(struct t
nr_possible_banks = be32_to_cpup( (__be32 *)&buf.data[TPM_HEADER_SIZE + 5]); - - chip->allocated_banks = kcalloc(nr_possible_banks, - sizeof(*chip->allocated_banks), - GFP_KERNEL); - if (!chip->allocated_banks) { + if (nr_possible_banks > TPM2_MAX_PCR_BANKS) { + pr_err("tpm: out of bank capacity: %u > %u\n", + nr_possible_banks, TPM2_MAX_PCR_BANKS); rc = -ENOMEM; goto out; } --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -26,7 +26,9 @@ #include <crypto/aes.h>
#define TPM_DIGEST_SIZE 20 /* Max TPM v1.2 PCR size */ -#define TPM_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE + +#define TPM2_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE +#define TPM2_MAX_PCR_BANKS 8
struct tpm_chip; struct trusted_key_payload; @@ -68,7 +70,7 @@ enum tpm2_curves {
struct tpm_digest { u16 alg_id; - u8 digest[TPM_MAX_DIGEST_SIZE]; + u8 digest[TPM2_MAX_DIGEST_SIZE]; } __packed;
struct tpm_bank_info { @@ -189,7 +191,7 @@ struct tpm_chip { unsigned int groups_cnt;
u32 nr_allocated_banks; - struct tpm_bank_info *allocated_banks; + struct tpm_bank_info allocated_banks[TPM2_MAX_PCR_BANKS]; #ifdef CONFIG_ACPI acpi_handle acpi_dev_handle; char ppi_version[TPM_PPI_VERSION_LEN + 1];