From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 85C50385D7B; Sat, 17 Oct 2026 17:29:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792258194; cv=none; b=cWHtNfT0rwkHt3rjQI1/vUcaZnXhQNKXVFuPbxdcRaUzh2r5nhrjOOPNBSYokhhKm8U+1DUdiADnnhaDAVTKB8sFMj7g+U8A0SevAeHYlAQ43HfTVFHf0espGLTdPLpIvMWZGigRF8fGbpEcQFshVrMQbYpvqvDGG0CIU0NhPtQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792258194; c=relaxed/simple; bh=IluWR79RPloSPDgY7zqC+XA9HPBgtAIkoxFfBZRc29g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=iNXD7pd1tdQT/hf6ScN91pzqu5TTGOqxdfU29YPu086QRxk/dkgx3ZHTNHQawS5RPiT8jQ8ogiT7xgifF9U15CzfZ4szIUHvRgugT4ZmZiYKH4Carl84t9rVqHMtFpSNGsK7ahoSl1Gu/nmi6Q8lkk6wqzTRLQPrVcI5uANGQdU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LtGEzDN3; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="LtGEzDN3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7BC401F000C4; Sat, 17 Oct 2026 17:29:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792258193; bh=Sx+6bDt2FylF8WL9XjMxC+0lF78+SBr7qrsfvQrOJao=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=LtGEzDN3FsRoTvsnsDxNhJBMIc+ZNC6Dudk9wuhPX6hbN7wRJQrUNnzGZgSYmhwt7 APu2durf5PE9dM2vAG3qljYEMGIgnzDjqgra4GFQkQxe1/NRIjFLVaAiwdISpaEE+m MeASfWa89A+Oo7mlhUGy7P3MoaJaerAnmUDScw/A= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Niklas Cassel , Manivannan Sadhasivam , Christian Bruel , =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= , Sasha Levin Subject: [PATCH 6.6 0750/1674] PCI: endpoint: pci-epf-test: Fix double free that causes kernel to oops Date: Sat, 17 Oct 2026 17:50:22 +0200 Message-ID: <20261017160450.355961307@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261017160431.119607952@linuxfoundation.org> References: <20261017160431.119607952@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christian Bruel [ Upstream commit 934e9d137d937706004c325fa1474f9e3f1ba10a ] Fix a kernel oops found while testing the stm32_pcie Endpoint driver with handling of PERST# deassertion: During EP initialization, pci_epf_test_alloc_space() allocates all BARs, which are further freed if epc_set_bar() fails (for instance, due to no free inbound window). However, when pci_epc_set_bar() fails, the error path: pci_epc_set_bar() -> pci_epf_free_space() does not clear the previous assignment to epf_test->reg[bar]. Then, if the host reboots, the PERST# deassertion restarts the BAR allocation sequence with the same allocation failure (no free inbound window), creating a double free situation since epf_test->reg[bar] was deallocated and is still non-NULL. Thus, make sure that pci_epf_alloc_space() and pci_epf_free_space() invocations are symmetric, and as such, set epf_test->reg[bar] to NULL when memory is freed. Reviewed-by: Niklas Cassel Reviewed-by: Manivannan Sadhasivam Signed-off-by: Christian Bruel Link: https://lore.kernel.org/r/20250124123043.96112-1-christian.bruel@foss.st.com [kwilczynski: commit log] Signed-off-by: Krzysztof Wilczyński Signed-off-by: Sasha Levin --- drivers/pci/endpoint/functions/pci-epf-test.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index 97c2ccdc6ad76..cf6e00802b53a 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -706,6 +706,7 @@ static void pci_epf_test_unbind(struct pci_epf *epf) epf_bar); pci_epf_free_space(epf, epf_test->reg[bar], bar, PRIMARY_INTERFACE); + epf_test->reg[bar] = NULL; } } } @@ -740,6 +741,7 @@ static int pci_epf_test_set_bar(struct pci_epf *epf) if (ret) { pci_epf_free_space(epf, epf_test->reg[bar], bar, PRIMARY_INTERFACE); + epf_test->reg[bar] = NULL; dev_err(dev, "Failed to set BAR%d\n", bar); if (bar == test_reg_bar) return ret; -- 2.53.0