From: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com
commit 6c4e79d99e6f42b79040f1a33cd4018f5425030b upstream.
The size of the buffers for storing context's and sessions can vary from arch to arch as PAGE_SIZE can be anything between 4 kB and 256 kB (the maximum for PPC64). Define a fixed buffer size set to 16 kB. This should be enough for most use with three handles (that is how many we allow at the moment). Parametrize the buffer size while doing this, so that it is easier to revisit this later on if required.
Cc: stable@vger.kernel.org Reported-by: Stefan Berger stefanb@linux.ibm.com Fixes: 745b361e989a ("tpm: infrastructure for TPM spaces") Reviewed-by: Jerry Snitselaar jsnitsel@redhat.com Tested-by: Stefan Berger stefanb@linux.ibm.com Signed-off-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/char/tpm/tpm-chip.c | 9 ++------- drivers/char/tpm/tpm.h | 5 ++++- drivers/char/tpm/tpm2-space.c | 26 ++++++++++++++++---------- drivers/char/tpm/tpmrm-dev.c | 2 +- include/linux/tpm.h | 1 + 5 files changed, 24 insertions(+), 19 deletions(-)
--- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -386,13 +386,8 @@ struct tpm_chip *tpm_chip_alloc(struct d chip->cdev.owner = THIS_MODULE; chip->cdevs.owner = THIS_MODULE;
- chip->work_space.context_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); - if (!chip->work_space.context_buf) { - rc = -ENOMEM; - goto out; - } - chip->work_space.session_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); - if (!chip->work_space.session_buf) { + rc = tpm2_init_space(&chip->work_space, TPM2_SPACE_BUFFER_SIZE); + if (rc) { rc = -ENOMEM; goto out; } --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -59,6 +59,9 @@ enum tpm_addr {
#define TPM_TAG_RQU_COMMAND 193
+/* TPM2 specific constants. */ +#define TPM2_SPACE_BUFFER_SIZE 16384 /* 16 kB */ + struct stclear_flags_t { __be16 tag; u8 deactivated; @@ -228,7 +231,7 @@ unsigned long tpm2_calc_ordinal_duration int tpm2_probe(struct tpm_chip *chip); int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip); int tpm2_find_cc(struct tpm_chip *chip, u32 cc); -int tpm2_init_space(struct tpm_space *space); +int tpm2_init_space(struct tpm_space *space, unsigned int buf_size); void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space); void tpm2_flush_space(struct tpm_chip *chip); int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u8 *cmd, --- a/drivers/char/tpm/tpm2-space.c +++ b/drivers/char/tpm/tpm2-space.c @@ -38,18 +38,21 @@ static void tpm2_flush_sessions(struct t } }
-int tpm2_init_space(struct tpm_space *space) +int tpm2_init_space(struct tpm_space *space, unsigned int buf_size) { - space->context_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); + space->context_buf = kzalloc(buf_size, GFP_KERNEL); if (!space->context_buf) return -ENOMEM;
- space->session_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); + space->session_buf = kzalloc(buf_size, GFP_KERNEL); if (space->session_buf == NULL) { kfree(space->context_buf); + /* Prevent caller getting a dangling pointer. */ + space->context_buf = NULL; return -ENOMEM; }
+ space->buf_size = buf_size; return 0; }
@@ -311,8 +314,10 @@ int tpm2_prepare_space(struct tpm_chip * sizeof(space->context_tbl)); memcpy(&chip->work_space.session_tbl, &space->session_tbl, sizeof(space->session_tbl)); - memcpy(chip->work_space.context_buf, space->context_buf, PAGE_SIZE); - memcpy(chip->work_space.session_buf, space->session_buf, PAGE_SIZE); + memcpy(chip->work_space.context_buf, space->context_buf, + space->buf_size); + memcpy(chip->work_space.session_buf, space->session_buf, + space->buf_size);
rc = tpm2_load_space(chip); if (rc) { @@ -492,7 +497,7 @@ static int tpm2_save_space(struct tpm_ch continue;
rc = tpm2_save_context(chip, space->context_tbl[i], - space->context_buf, PAGE_SIZE, + space->context_buf, space->buf_size, &offset); if (rc == -ENOENT) { space->context_tbl[i] = 0; @@ -509,9 +514,8 @@ static int tpm2_save_space(struct tpm_ch continue;
rc = tpm2_save_context(chip, space->session_tbl[i], - space->session_buf, PAGE_SIZE, + space->session_buf, space->buf_size, &offset); - if (rc == -ENOENT) { /* handle error saving session, just forget it */ space->session_tbl[i] = 0; @@ -557,8 +561,10 @@ int tpm2_commit_space(struct tpm_chip *c sizeof(space->context_tbl)); memcpy(&space->session_tbl, &chip->work_space.session_tbl, sizeof(space->session_tbl)); - memcpy(space->context_buf, chip->work_space.context_buf, PAGE_SIZE); - memcpy(space->session_buf, chip->work_space.session_buf, PAGE_SIZE); + memcpy(space->context_buf, chip->work_space.context_buf, + space->buf_size); + memcpy(space->session_buf, chip->work_space.session_buf, + space->buf_size);
return 0; out: --- a/drivers/char/tpm/tpmrm-dev.c +++ b/drivers/char/tpm/tpmrm-dev.c @@ -21,7 +21,7 @@ static int tpmrm_open(struct inode *inod if (priv == NULL) return -ENOMEM;
- rc = tpm2_init_space(&priv->space); + rc = tpm2_init_space(&priv->space, TPM2_SPACE_BUFFER_SIZE); if (rc) { kfree(priv); return -ENOMEM; --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -96,6 +96,7 @@ struct tpm_space { u8 *context_buf; u32 session_tbl[3]; u8 *session_buf; + u32 buf_size; };
struct tpm_bios_log {