From: Thomas Gleixner tglx@linutronix.de
commit efa165504943f2128d50f63de0c02faf6dcceb0d upstream.
If access_ok() or fpregs_soft_set() fails in __fpu__restore_sig() then the function just returns but does not clear the FPU state as it does for all other fatal failures.
Clear the FPU state for these failures as well.
Fixes: 72a671ced66d ("x86, fpu: Unify signal handling code paths for x86 and x86_64 kernels") Signed-off-by: Thomas Gleixner tglx@linutronix.de Signed-off-by: Borislav Petkov bp@suse.de Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/87mtryyhhz.ffs@nanos.tec.linutronix.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kernel/fpu/signal.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index 769831d9fd11..07b0ebd49576 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -276,15 +276,23 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size) return 0; }
- if (!access_ok(VERIFY_READ, buf, size)) + if (!access_ok(VERIFY_READ, buf, size)) { + fpu__clear(fpu); return -EACCES; + }
fpu__activate_curr(fpu);
- if (!static_cpu_has(X86_FEATURE_FPU)) - return fpregs_soft_set(current, NULL, - 0, sizeof(struct user_i387_ia32_struct), - NULL, buf) != 0; + if (!static_cpu_has(X86_FEATURE_FPU)) { + int ret = fpregs_soft_set(current, NULL, 0, + sizeof(struct user_i387_ia32_struct), + NULL, buf); + + if (ret) + fpu__clear(fpu); + + return ret != 0; + }
if (use_xsave()) { struct _fpx_sw_bytes fx_sw_user;