From nobody Sat Feb 7 04:47:24 2026 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0BE0D1EE7C6 for ; Mon, 2 Feb 2026 18:33:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770057197; cv=none; b=uxEovuJJSG0hc9vOohV58WPjNbK/dpn1OjOg1kLhQmkLt1yPTykMGZeh9QfPvjHueXWq3BXwmNDXttZwC0g4sS8gS1UorwPuBRN0grqpwq+XvMwSazNVn9M7N0biNbWL8WGDhDehwXW2YU3w1/2gGtutgmQKW4bON7FmuQPush0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770057197; c=relaxed/simple; bh=MmPseQkgfaXXHt/9anSYmv5Kd61ckl4pLRDdwCFqgN4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=VQNdVnreU8oazgiKMCwl8Jz6xBafYYMdJx35XIX/WvFv58Alhp9InnZpFt2CZwHT9VMlBVdol2pe7lBKoNYbGT/az8oD+gdz6mnaRjIZXW/GWRsD+OWlZ9+Dsg2USTIm967afQ0u88zSKqtbPTfLG9Txi7xO0DMI316S8u4agqY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org; spf=none smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=tTDixZsK; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="tTDixZsK" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:Cc:To:Message-Id: Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date:From: Reply-To:Content-ID:Content-Description:In-Reply-To:References; bh=y0SQA2DCPtCAyrCB1taAmCcHiX9Y9ssa35y7xR4oBdg=; b=tTDixZsKE24SXoghdvPSJIy8bc OY+nKwrZMGHsblrqfVwV+w5FzXC4t0XVVaaBBBZLJsSWb0WmCBybILhPr+TbSpU2xYj1m0+dYUkHi GVb/T3KLnt+/2P9nV8NjF5SfretBVNqa+HbAzxlxtrIMoE6Wrhe+0fzl3u6COvhsLNQev2LyKRuA2 4ct4blldhRSM0ke44hB0deUx1+jbr92jFIHpXXqlkSwxEkvq2YPF1UthY+Dxo0KxkBSmNALUNn2E+ qDwzGSAvDXLcGsnH+Zh1G7IlUutt6iVONhthX+0mkIt6y0VUpbEJlB2EPCFoSa5k1HlrWgzyG68Lo yb0ORK4A==; Received: from authenticated user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94.2) (envelope-from ) id 1vmyjP-004Eqm-Q4; Mon, 02 Feb 2026 18:33:04 +0000 From: Breno Leitao Date: Mon, 02 Feb 2026 10:32:51 -0800 Subject: [PATCH v2] arm64/gcs: Fix error handling in arch_set_shadow_stack_status() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260202-arm64_cgs-v2-1-e6a837edf021@debian.org> X-B4-Tracking: v=1; b=H4sIANLtgGkC/03N0QrCIBTG8VeRcz1DzVzuqveIEdOdthM0Q5cUw 3ePrS66/ODP71sgYSRM0LAFImZKFCZomKoY+LGbBuTUQ8NACWWEVJZ38W70xQ+Ja2uOshbq0Eu EisEj4pVem3Vuvzs93Q39vAJrMVKaQ3xvZ1mu3c/diz83Sy65t85YrZxxtTj16KibdiEO0JZSP mSeIOa1AAAA X-Change-ID: 20260129-arm64_cgs-496817025d1e To: Catalin Marinas , Will Deacon , Thiago Jung Bauermann , Mark Brown Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, Breno Leitao X-Mailer: b4 0.15-dev-f4305 X-Developer-Signature: v=1; a=openpgp-sha256; l=1367; i=leitao@debian.org; h=from:subject:message-id; bh=MmPseQkgfaXXHt/9anSYmv5Kd61ckl4pLRDdwCFqgN4=; b=owEBbAKT/ZANAwAIATWjk5/8eHdtAcsmYgBpgO3bMxMjQORPcK48PqktX1No+2mRwB7F6LhCu zXTewSqDOiJAjIEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCaYDt2wAKCRA1o5Of/Hh3 bZSVD/dytK0P3BZSDUHDJxU/yCmzV6hGAp5K8Q5aOuTXPXFXcl1Xw3hiMz4hOEzRzBKnH9tt0gZ 6rAul496Tnusr5EATsIjSFd8D2MZKcnMV1L2TShE7vB8DbPN4txylihnsrpI/DqTzEs5tuO7Io5 s0kMxxdJGy13qGD2bxxJAwpNTIt1/bST8KPhoOwhJgyyt2Io3K0p6AHmWrx1Vt8ozzlbH1i7+Ql 3rm5Q34NufWbf1xu8JS9lm7eGL5oELHK05TvbabeuKdLffi8pa8KrnjHb8wWV+/xGCcWNKJHliz oEtlEslte00pLwVYBBvwqFwhYrFr+5bhtXTVuPbbKw71uyC3Jw24tR9vnZj5RF0dGFuyitd0Rfv 7NhrkrncuuoJdk1+fp1pou8z9DBjdvt16J26L2XUZpLBd55xMZ0Bmi+bEzGGBcemrgcdI6HmhHN EoY0yo1uUeIR0KLFDuNjcJY5yLhdFZMMiIkhdC7DlsIPoJkrHWdZzAh+CkA0+dSzUHrM6cmb/22 rrRNH3N/uUPHptRhBbpqOPBYx/emTfJbOrs0kUrbY64aSkuKA5Rf10fKLhAuRktDQlGKzOlxqvW xsOnOfcbHVERVuiMqAhAIbWcYiQqdWjx1wNxEjgp2PtxSL6s4C9MQpLq8FzEyVpw5x1HQW78Q2X 1RClQ37Qc5hyq X-Developer-Key: i=leitao@debian.org; a=openpgp; fpr=AC8539A6E8F46702CA4A439B35A3939FFC78776D X-Debian-User: leitao alloc_gcs() returns an error-encoded pointer on failure, which comes from do_mmap(), not NULL. The current NULL check fails to detect errors, which could lead to using an invalid GCS address. Use IS_ERR_VALUE() to properly detect errors, consistent with the check in gcs_alloc_thread_stack(). Fixes: b57180c75c7eb ("arm64/gcs: Implement shadow stack prctl() interface") Reviewed-by: Mark Brown Signed-off-by: Breno Leitao --- Changes in v2: - Remove unnecessary PTR_ERR() conversion (Will) - Link to v1: https://patch.msgid.link/20260130-arm64_cgs-v1-1-c9b6942b6b70= @debian.org --- arch/arm64/mm/gcs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/mm/gcs.c b/arch/arm64/mm/gcs.c index 6e93f78de79b1..04a23a497f205 100644 --- a/arch/arm64/mm/gcs.c +++ b/arch/arm64/mm/gcs.c @@ -199,8 +199,8 @@ int arch_set_shadow_stack_status(struct task_struct *ta= sk, unsigned long arg) =20 size =3D gcs_size(0); gcs =3D alloc_gcs(0, size); - if (!gcs) - return -ENOMEM; + if (IS_ERR_VALUE(gcs)) + return gcs; =20 task->thread.gcspr_el0 =3D gcs + size - sizeof(u64); task->thread.gcs_base =3D gcs; --- base-commit: 8dfce8991b95d8625d0a1d2896e42f93b9d7f68d change-id: 20260129-arm64_cgs-496817025d1e Best regards, -- =20 Breno Leitao