@@ -271,18 +271,20 @@ static int preserve_sve_context(struct sve_context __user *ctx)
static int restore_sve_fpsimd_context(struct user_ctxs *user)
{
- int err;
+ int err = 0;
unsigned int vl, vq;
struct user_fpsimd_state fpsimd;
- struct sve_context sve;
+ u16 user_vl, flags;
if (user->sve_size < sizeof(*user->sve))
return -EINVAL;
- if (__copy_from_user(&sve, user->sve, sizeof(sve)))
- return -EFAULT;
+ __get_user_error(user_vl, &(user->sve->vl), err);
+ __get_user_error(flags, &(user->sve->flags), err);
+ if (err)
+ return err;
- if (sve.flags & SVE_SIG_FLAG_SM) {
+ if (flags & SVE_SIG_FLAG_SM) {
if (!system_supports_sme())
return -EINVAL;
@@ -294,7 +296,7 @@ static int restore_sve_fpsimd_context(struct user_ctxs *user)
vl = task_get_sve_vl(current);
}
- if (sve.vl != vl)
+ if (user_vl != vl)
return -EINVAL;
if (user->sve_size == sizeof(*user->sve)) {
@@ -304,7 +306,7 @@ static int restore_sve_fpsimd_context(struct user_ctxs *user)
goto fpsimd_only;
}
- vq = sve_vq_from_vl(sve.vl);
+ vq = sve_vq_from_vl(vl);
if (user->sve_size < SVE_SIG_CONTEXT_SIZE(vq))
return -EINVAL;
@@ -332,7 +334,7 @@ static int restore_sve_fpsimd_context(struct user_ctxs *user)
if (err)
return -EFAULT;
- if (sve.flags & SVE_SIG_FLAG_SM)
+ if (flags & SVE_SIG_FLAG_SM)
current->thread.svcr |= SVCR_SM_MASK;
else
set_thread_flag(TIF_SVE);
When we parse the SVE signal context we read the entire context from userspace, including the generic signal context header which was already read by parse_user_sigframe() and padding bytes that we ignore. Avoid the possibility of relying on the second read of the data read twice by only reading the data which we are actually going to use. Signed-off-by: Mark Brown <broonie@kernel.org> --- arch/arm64/kernel/signal.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)