6.9-stable review patch. If anyone has any objections, please let me know.
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From: Matthew R. Ochs mochs@nvidia.com
[ Upstream commit 195aba96b854dd664768f382cd1db375d8181f88 ]
The TPM SPI transfer mechanism uses MAX_SPI_FRAMESIZE for computing the maximum transfer length and the size of the transfer buffer. As such, it does not account for the 4 bytes of header that prepends the SPI data frame. This can result in out-of-bounds accesses and was confirmed with KASAN.
Introduce SPI_HDRSIZE to account for the header and use to allocate the transfer buffer.
Fixes: a86a42ac2bd6 ("tpm_tis_spi: Add hardware wait polling") Signed-off-by: Matthew R. Ochs mochs@nvidia.com Tested-by: Carol Soto csoto@nvidia.com Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/char/tpm/tpm_tis_spi_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/char/tpm/tpm_tis_spi_main.c b/drivers/char/tpm/tpm_tis_spi_main.c index 3f9eaf27b41b8..c9eca24bbad47 100644 --- a/drivers/char/tpm/tpm_tis_spi_main.c +++ b/drivers/char/tpm/tpm_tis_spi_main.c @@ -37,6 +37,7 @@ #include "tpm_tis_spi.h"
#define MAX_SPI_FRAMESIZE 64 +#define SPI_HDRSIZE 4
/* * TCG SPI flow control is documented in section 6.4 of the spec[1]. In short, @@ -247,7 +248,7 @@ static int tpm_tis_spi_write_bytes(struct tpm_tis_data *data, u32 addr, int tpm_tis_spi_init(struct spi_device *spi, struct tpm_tis_spi_phy *phy, int irq, const struct tpm_tis_phy_ops *phy_ops) { - phy->iobuf = devm_kmalloc(&spi->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL); + phy->iobuf = devm_kmalloc(&spi->dev, SPI_HDRSIZE + MAX_SPI_FRAMESIZE, GFP_KERNEL); if (!phy->iobuf) return -ENOMEM;