From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A0B264657C4 for ; Wed, 17 Jun 2026 14:51:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781707910; cv=none; b=TaMpFVCLZjLPZUdc9f2HVW2Y3zVb4qNwRJlGdw2CyFHz4PWIJe4WPiruwsCDLEsLzdeSYwvBx6b4B9GHg+RlNajVhllni05HMN4QMfmyMhmWvWSvDAIlDGbZ2a7MEAI1e6/xAHGzbtKEE9dOMQ+8q4FmidgGHytvBzPb9fWwxDQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781707910; c=relaxed/simple; bh=RYLphXY3qZrHLwVyATq2rz6ULfSNbmNMCCt4D1nRClw=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=k2ueyi5Tvhw/eaVyusQmn9S+H6jTgeJ4rRTSBEOTryXOu71w1QHKIvphbXZdabcEtaEuBLL00pLiMgpH3BRtdYe5Jv5nBYFLfXkZdyueM8y7Om7jd7uRj+8LrhSNh3gXh0IprxAeT6X8KRazGX1G98WqoR+uBZwd7coXvNESgGk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--sebastianene.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=uHi+K1nL; arc=none smtp.client-ip=209.85.128.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--sebastianene.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="uHi+K1nL" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-490a767c7dcso38131805e9.2 for ; Wed, 17 Jun 2026 07:51:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1781707907; x=1782312707; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=CQFj/8TPJyuneEGc/c18D84EbHbY3hzTyS99LAP/4do=; b=uHi+K1nLH7ImWQgVCW4E5prxD7zwtzVkGOZSWsJkW0o+oDohIEtX/XSohRwFNvfkGE GkUB9f9+FGFDdzI1xXAsbo/gNqFj3oAn7IgujlEom7t8XpJOCUUUfMEAP3mra2uvwGmA 0NYgva7bjR5IJbzlzPWeGLMHoXnqmNqKDcfG5daF0mB2BzULU9YN5fGcvimp/jQntsef qyYZjZYe8mKTmAFvWKxSuhPWzE3DltAf5rJmnpr6DhSEyklbgHJgss8tnBLVtWEz3IkG wYG7F/4fdK465eQLeWkXEdXKZq4Pv+3Hghb5m6ypvRulK2goBWBzlUvniFScLBtwVLTc azNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781707907; x=1782312707; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=CQFj/8TPJyuneEGc/c18D84EbHbY3hzTyS99LAP/4do=; b=rlnwkJIAfFmkm8eyMv3qShYoPt5eOGWqdqvAM+0knYgOWVl22i8hRZ7oPJuuoAqpGu b7VF1ppFzbOptYWxX5DR1ZzSBwO27NoIUU1SiSY7W1fH2vxEoTzhSyn3j5y4qzq9uEwQ /K10za06bG9c2xZhN1EScfQBYIIveFUU/rhdrY1etrAWNiG3EYgDHsP1DGBD03BTSSzy k+xe9AGfroTCC2SGSoO1IZJQfc6RNViNjrRTwojHrDCsms5fUsxD6rDAeEtTAoAn/KH+ Lv0ci7lKypd7DlRU8kJVl12AK/JaSTGVD4P3HJENqUwFstGVwXTY3KDa7bl9OoCOnqfN vSww== X-Forwarded-Encrypted: i=1; AFNElJ8qPfB+/kI//daKkVVjniSOak9VAkEYUirB1s2qIq4GPQqxNFiuEdUBQp+2x4eOdS6y6+Vrk4ozPZuVOUY=@vger.kernel.org X-Gm-Message-State: AOJu0YxZwfHE8t/CM1VR3nSeQwaCiMLcLAFaouiWJyQWx2wtdtTcWJBg ir9kBhFqXEVXNDviYF6dxi1ONT+ADlN7DWOvvJBzPw3za6JxzqaCBGz+QUvttX13vlM0G+toLz7 h9nP+FYxhacFZjkp/C8aTVDJMCagTyw== X-Received: from wmbju24.prod.google.com ([2002:a05:600c:56d8:b0:490:b18a:b4e2]) (user=sebastianene job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:828e:b0:492:2e7a:9ba7 with SMTP id 5b1f17b1804b1-4923339fca0mr74090555e9.3.1781707906450; Wed, 17 Jun 2026 07:51:46 -0700 (PDT) Date: Wed, 17 Jun 2026 14:51:27 +0000 In-Reply-To: <20260617145130.3729015-1-sebastianene@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260617145130.3729015-1-sebastianene@google.com> X-Mailer: git-send-email 2.54.0.1136.gdb2ca164c4-goog Message-ID: <20260617145130.3729015-5-sebastianene@google.com> Subject: [PATCH v7 4/7] KVM: arm64: Fix bounds checking in do_ffa_mem_reclaim() From: Sebastian Ene To: catalin.marinas@arm.com, oupton@kernel.org, sudeep.holla@kernel.org, will@kernel.org Cc: jens.wiklander@linaro.org, joey.gouly@arm.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, android-kvm@google.com, maz@kernel.org, mrigendra.chaubey@gmail.com, op-tee@lists.trustedfirmware.org, perlarsen@google.com, sebastianene@google.com, seiden@linux.ibm.com, smostafa@google.com, sumit.garg@kernel.org, suzuki.poulose@arm.com, vdonnefort@google.com, yuzenghui@huawei.com Content-Type: text/plain; charset="UTF-8" From: Mostafa Saleh Sashiko (locally) reports out of bound write possiblity if SPMD returns an invalid data. While SPMD is considered trusted, pKVM does some basic checks, for offset to be less than or equal len. However, that is incorrect as even if the offset is smaller than len pKVM can still access out of bound memory in the next ffa_host_unshare_ranges(). Split this check into 2: 1- Check that the fixed portion of the descriptor fits. 2- After getting reg, check the variable array size addr_range_cnt fits. Also, drop the WARN_ONs as that will panic the kernel and in the next checks there are no WARNs, so that makes it consistent. Fixes: 0a9f15fd5674 ("KVM: arm64: pkvm: Add support for fragmented FF-A descriptors") Signed-off-by: Mostafa Saleh Signed-off-by: Sebastian Ene --- arch/arm64/kvm/hyp/nvhe/ffa.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index 1af722771178..2d211661952e 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -607,8 +607,8 @@ static void do_ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, * check that we end up with something that doesn't look _completely_ * bogus. */ - if (WARN_ON(offset > len || - fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE)) { + if (offset + CONSTITUENTS_OFFSET(0) > len || + fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) { ret = FFA_RET_ABORTED; ffa_rx_release(res); goto out_unlock; @@ -636,11 +636,17 @@ static void do_ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, ffa_rx_release(res); } + reg = (void *)buf + offset; + if (offset + CONSTITUENTS_OFFSET(reg->addr_range_cnt) > len) { + ret = FFA_RET_ABORTED; + ffa_rx_release(res); + goto out_unlock; + } + ffa_mem_reclaim(res, handle_lo, handle_hi, flags); if (res->a0 != FFA_SUCCESS) goto out_unlock; - reg = (void *)buf + offset; /* If the SPMD was happy, then we should be too. */ WARN_ON(ffa_host_unshare_ranges(reg->constituents, reg->addr_range_cnt)); -- 2.54.0.1136.gdb2ca164c4-goog