Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL for 3.18 058/101] arm64: ptrace: Fix incorrect get_user() use in compat_vfp_set() | Date | Mon, 9 Apr 2018 00:41:21 +0000 |
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From: Dave Martin <Dave.Martin@arm.com>
[ Upstream commit 5fbd5fc49fc39ac8433da62d16682a1d0217ea4f ]
Now that compat_vfp_get() uses the regset API to copy the FPSCR value out to userspace, compat_vfp_set() looks inconsistent. In particular, compat_vfp_set() will fail if called with kbuf != NULL && ubuf == NULL (which is valid usage according to the regset API).
This patch fixes compat_vfp_set() to use user_regset_copyin(), similarly to compat_vfp_get().
This also squashes a sparse warning triggered by the cast that drops __user when calling get_user().
Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> --- arch/arm64/kernel/ptrace.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index a12eb17e7985..01defb4527f4 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -773,18 +773,20 @@ static int compat_vfp_set(struct task_struct *target, { struct user_fpsimd_state *uregs; compat_ulong_t fpscr; - int ret; + int ret, vregs_end_pos; if (pos + count > VFP_STATE_SIZE) return -EIO; uregs = &target->thread.fpsimd_state.user_fpsimd; + vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t); ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0, - VFP_STATE_SIZE - sizeof(compat_ulong_t)); + vregs_end_pos); if (count && !ret) { - ret = get_user(fpscr, (compat_ulong_t *)ubuf); + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpscr, + vregs_end_pos, VFP_STATE_SIZE); if (!ret) { uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK; uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK; -- 2.15.1
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