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x86/fpu: Reset state for all signal restore failures

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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: 72a671ced6 ("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>
This commit is contained in:
Thomas Gleixner
2021-06-09 21:18:00 +02:00
committed by Greg Kroah-Hartman
parent a7748e021b
commit 63ba83563e
1 changed files with 15 additions and 11 deletions
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26
arch/x86/kernel/fpu/signal.c
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@@ -307,13 +307,17 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
return 0; return 0;
} }
if (!access_ok(buf, size)) if (!access_ok(buf, size)) {
return -EACCES; ret = -EACCES;
goto out;
}
if (!static_cpu_has(X86_FEATURE_FPU)) if (!static_cpu_has(X86_FEATURE_FPU)) {
return fpregs_soft_set(current, NULL, ret = fpregs_soft_set(current, NULL, 0,
0, sizeof(struct user_i387_ia32_struct), sizeof(struct user_i387_ia32_struct),
NULL, buf) != 0; NULL, buf);
goto out;
}
if (use_xsave()) { if (use_xsave()) {
struct _fpx_sw_bytes fx_sw_user; struct _fpx_sw_bytes fx_sw_user;
@@ -396,7 +400,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
*/ */
ret = __copy_from_user(&env, buf, sizeof(env)); ret = __copy_from_user(&env, buf, sizeof(env));
if (ret) if (ret)
goto err_out; goto out;
envp = &env; envp = &env;
} }
@@ -426,7 +430,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
ret = copy_user_to_xstate(&fpu->state.xsave, buf_fx); ret = copy_user_to_xstate(&fpu->state.xsave, buf_fx);
if (ret) if (ret)
goto err_out; goto out;
sanitize_restored_user_xstate(&fpu->state, envp, user_xfeatures, sanitize_restored_user_xstate(&fpu->state, envp, user_xfeatures,
fx_only); fx_only);
@@ -446,7 +450,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
ret = __copy_from_user(&fpu->state.fxsave, buf_fx, state_size); ret = __copy_from_user(&fpu->state.fxsave, buf_fx, state_size);
if (ret) { if (ret) {
ret = -EFAULT; ret = -EFAULT;
goto err_out; goto out;
} }
sanitize_restored_user_xstate(&fpu->state, envp, user_xfeatures, sanitize_restored_user_xstate(&fpu->state, envp, user_xfeatures,
@@ -464,7 +468,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
} else { } else {
ret = __copy_from_user(&fpu->state.fsave, buf_fx, state_size); ret = __copy_from_user(&fpu->state.fsave, buf_fx, state_size);
if (ret) if (ret)
goto err_out; goto out;
fpregs_lock(); fpregs_lock();
ret = copy_kernel_to_fregs_err(&fpu->state.fsave); ret = copy_kernel_to_fregs_err(&fpu->state.fsave);
@@ -475,7 +479,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
fpregs_deactivate(fpu); fpregs_deactivate(fpu);
fpregs_unlock(); fpregs_unlock();
err_out: out:
if (ret) if (ret)
fpu__clear_user_states(fpu); fpu__clear_user_states(fpu);
return ret; return ret;