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).
Reported-by: Stefan Berger stefanb@linux.ibm.com Cc: stable@vger.kernel.org Fixes: 745b361e989a ("tpm: infrastructure for TPM spaces") Signed-off-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com --- drivers/char/tpm/tpm2-space.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-)
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c index 982d341d8837..9bef646093d1 100644 --- a/drivers/char/tpm/tpm2-space.c +++ b/drivers/char/tpm/tpm2-space.c @@ -15,6 +15,8 @@ #include <asm/unaligned.h> #include "tpm.h"
+#define TPM2_SPACE_BUFFER_SIZE 16384 /* 16 kB */ + enum tpm2_handle_types { TPM2_HT_HMAC_SESSION = 0x02000000, TPM2_HT_POLICY_SESSION = 0x03000000, @@ -40,11 +42,11 @@ static void tpm2_flush_sessions(struct tpm_chip *chip, struct tpm_space *space)
int tpm2_init_space(struct tpm_space *space) { - space->context_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); + space->context_buf = kzalloc(TPM2_SPACE_BUFFER_SIZE, GFP_KERNEL); if (!space->context_buf) return -ENOMEM;
- space->session_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); + space->session_buf = kzalloc(TPM2_SPACE_BUFFER_SIZE, GFP_KERNEL); if (space->session_buf == NULL) { kfree(space->context_buf); return -ENOMEM; @@ -311,8 +313,10 @@ int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u8 *cmd, 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, + TPM2_SPACE_BUFFER_SIZE); + memcpy(chip->work_space.session_buf, space->session_buf, + TPM2_SPACE_BUFFER_SIZE);
rc = tpm2_load_space(chip); if (rc) { @@ -492,8 +496,8 @@ static int tpm2_save_space(struct tpm_chip *chip) continue;
rc = tpm2_save_context(chip, space->context_tbl[i], - space->context_buf, PAGE_SIZE, - &offset); + space->context_buf, + TPM2_SPACE_BUFFER_SIZE, &offset); if (rc == -ENOENT) { space->context_tbl[i] = 0; continue; @@ -509,9 +513,8 @@ static int tpm2_save_space(struct tpm_chip *chip) continue;
rc = tpm2_save_context(chip, space->session_tbl[i], - space->session_buf, PAGE_SIZE, - &offset); - + space->session_buf, + TPM2_SPACE_BUFFER_SIZE, &offset); if (rc == -ENOENT) { /* handle error saving session, just forget it */ space->session_tbl[i] = 0; @@ -557,8 +560,10 @@ int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space, 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, + TPM2_SPACE_BUFFER_SIZE); + memcpy(space->session_buf, chip->work_space.session_buf, + TPM2_SPACE_BUFFER_SIZE);
return 0; out: