diff options
| author | Jann Horn <jannh@google.com> | 2025-04-28 15:06:43 +0200 |
|---|---|---|
| committer | Jens Wiklander <jens.wiklander@linaro.org> | 2025-04-30 14:57:03 +0200 |
| commit | 39bb67edcc582b3b386a9ec983da67fa8a10ec03 (patch) | |
| tree | 39adeb70868ae40467e5266129da951cfd51541b | |
| parent | 26104d81567376b2038c4f52c90d849ee32639a9 (diff) | |
tee: Prevent size calculation wraparound on 32-bit kernels
The current code around TEE_IOCTL_PARAM_SIZE() is a bit wrong on
32-bit kernels: Multiplying a user-provided 32-bit value with the
size of a structure can wrap around on such platforms.
Fix it by using saturating arithmetic for the size calculation.
This has no security consequences because, in all users of
TEE_IOCTL_PARAM_SIZE(), the subsequent kcalloc() implicitly checks
for wrapping.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Tested-by: Rouven Czerwinski <rouven.czerwinski@linaro.org>
| -rw-r--r-- | drivers/tee/tee_core.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index d113679b1e2d..acc7998758ad 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -10,6 +10,7 @@ #include <linux/fs.h> #include <linux/idr.h> #include <linux/module.h> +#include <linux/overflow.h> #include <linux/slab.h> #include <linux/tee_core.h> #include <linux/uaccess.h> @@ -19,7 +20,7 @@ #define TEE_NUM_DEVICES 32 -#define TEE_IOCTL_PARAM_SIZE(x) (sizeof(struct tee_param) * (x)) +#define TEE_IOCTL_PARAM_SIZE(x) (size_mul(sizeof(struct tee_param), (x))) #define TEE_UUID_NS_NAME_SIZE 128 @@ -487,7 +488,7 @@ static int tee_ioctl_open_session(struct tee_context *ctx, if (copy_from_user(&arg, uarg, sizeof(arg))) return -EFAULT; - if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len) + if (size_add(sizeof(arg), TEE_IOCTL_PARAM_SIZE(arg.num_params)) != buf.buf_len) return -EINVAL; if (arg.num_params) { @@ -565,7 +566,7 @@ static int tee_ioctl_invoke(struct tee_context *ctx, if (copy_from_user(&arg, uarg, sizeof(arg))) return -EFAULT; - if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len) + if (size_add(sizeof(arg), TEE_IOCTL_PARAM_SIZE(arg.num_params)) != buf.buf_len) return -EINVAL; if (arg.num_params) { @@ -699,7 +700,7 @@ static int tee_ioctl_supp_recv(struct tee_context *ctx, if (get_user(num_params, &uarg->num_params)) return -EFAULT; - if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) != buf.buf_len) + if (size_add(sizeof(*uarg), TEE_IOCTL_PARAM_SIZE(num_params)) != buf.buf_len) return -EINVAL; params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL); @@ -798,7 +799,7 @@ static int tee_ioctl_supp_send(struct tee_context *ctx, get_user(num_params, &uarg->num_params)) return -EFAULT; - if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) > buf.buf_len) + if (size_add(sizeof(*uarg), TEE_IOCTL_PARAM_SIZE(num_params)) > buf.buf_len) return -EINVAL; params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL); |