From patchwork Thu Apr 24 07:32:51 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Youling Tang X-Patchwork-Id: 885101 Received: from out-170.mta0.migadu.com (out-170.mta0.migadu.com [91.218.175.170]) (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 089311F4C8E for ; Thu, 24 Apr 2025 07:33:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.170 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745480037; cv=none; b=PYKp0HiStc62BRcYuJ9tosWXoofCizGcCbXSwb+XnFh5HO2h2koWq0td79znsBsKDk9sVIaWsxMkGAsCDzq/egFzyk/6T2C03vs5Tx+yDD5OLBnmYkSyJM1kQNJr5vZmDANavEuRbuqGbfhpUMP+mhmuEZNedQpWqBq3pBQnRTM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745480037; c=relaxed/simple; bh=i/pah3/ayjAO/+aYM6UW7bpVrgnfwVgrntYyeusc23c=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=iY3bLfPjC08KaGMEKfbaOYNRlsvc0ORmW/uwWzfR7Zc3qUCAVlgUARapiUaZDimnW1mwYciiCAtTTMjbjPeUG2z7md8rfaE/1X2tRoRoYq0aKxDyLMdSVh23yRfIwWPybFmucPsh50hsMluDqcZCd5wewb1lr/Jfu3G1Cbw7Zrk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=wmJI89q6; arc=none smtp.client-ip=91.218.175.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="wmJI89q6" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1745480032; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=4B2ZQBcaf4MHaBSs41nBV6qBgnq5T9kD57Vq4ebmRek=; b=wmJI89q69mE2/kPtEha6yeirHqMtjh7wJvhtLrd4jEKRXso4Ql6gfGCkndK7FmCdA+NvWZ MSYVIBZxT5dUrjosuAsR2JDF2QG6t9q+pH8Zsn2p70Dm/w8zCaXdEpUFsBeijzHno2/WVe AiEAUc9Gz50W9/VxC/E/2y5Sb0TpnmI= From: Youling Tang To: Huacai Chen Cc: Ard Biesheuvel , loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, youling.tang@linux.dev, Youling Tang Subject: [PATCH v2] LoongArch: Enable HAVE_ARCH_STACKLEAK Date: Thu, 24 Apr 2025 15:32:51 +0800 Message-Id: <20250424073251.81693-1-youling.tang@linux.dev> Precedence: bulk X-Mailing-List: linux-efi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT From: Youling Tang Add support for the stackleak feature. It initialize the stack with the poison value before returning from system calls which improves the kernel security. At the same time, disables the plugin in EFI stub code because EFI stub is out of scope for the protection. Tested on 3A5000 (enable CONFIG_GCC_PLUGIN_STACKLEAK and CONFIG_LKDTM): # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT # dmesg lkdtm: Performing direct entry STACKLEAK_ERASING lkdtm: stackleak stack usage: high offset: 320 bytes current: 448 bytes lowest: 1264 bytes tracked: 1264 bytes untracked: 208 bytes poisoned: 14528 bytes low offset: 64 bytes lkdtm: OK: the rest of the thread stack is properly erased Signed-off-by: Youling Tang --- v2: * Make on_thread_stack() __always_inline. * Move the STACKLEAK_ERASE macro to the stackframe.h file. arch/loongarch/Kconfig | 1 + arch/loongarch/include/asm/entry-common.h | 8 +------- arch/loongarch/include/asm/stackframe.h | 6 ++++++ arch/loongarch/include/asm/stacktrace.h | 5 +++++ arch/loongarch/kernel/entry.S | 3 +++ drivers/firmware/efi/libstub/Makefile | 2 +- 6 files changed, 17 insertions(+), 8 deletions(-) diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 067c0b994648..3a6bfcab2dde 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -122,6 +122,7 @@ config LOONGARCH select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET select HAVE_ARCH_SECCOMP select HAVE_ARCH_SECCOMP_FILTER + select HAVE_ARCH_STACKLEAK select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_TRANSPARENT_HUGEPAGE select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD diff --git a/arch/loongarch/include/asm/entry-common.h b/arch/loongarch/include/asm/entry-common.h index 0fe2a098ded9..a7a6af490f86 100644 --- a/arch/loongarch/include/asm/entry-common.h +++ b/arch/loongarch/include/asm/entry-common.h @@ -2,12 +2,6 @@ #ifndef ARCH_LOONGARCH_ENTRY_COMMON_H #define ARCH_LOONGARCH_ENTRY_COMMON_H -#include -#include - -static inline bool on_thread_stack(void) -{ - return !(((unsigned long)(current->stack) ^ current_stack_pointer) & ~(THREAD_SIZE - 1)); -} +#include #endif diff --git a/arch/loongarch/include/asm/stackframe.h b/arch/loongarch/include/asm/stackframe.h index 66736837085b..c37455bca29b 100644 --- a/arch/loongarch/include/asm/stackframe.h +++ b/arch/loongarch/include/asm/stackframe.h @@ -243,4 +243,10 @@ RESTORE_SP_AND_RET \docfi .endm + .macro STACKLEAK_ERASE +#ifdef CONFIG_GCC_PLUGIN_STACKLEAK + bl stackleak_erase_on_task_stack +#endif + .endm + #endif /* _ASM_STACKFRAME_H */ diff --git a/arch/loongarch/include/asm/stacktrace.h b/arch/loongarch/include/asm/stacktrace.h index fc8b64773794..5c8be156567c 100644 --- a/arch/loongarch/include/asm/stacktrace.h +++ b/arch/loongarch/include/asm/stacktrace.h @@ -31,6 +31,11 @@ bool in_irq_stack(unsigned long stack, struct stack_info *info); bool in_task_stack(unsigned long stack, struct task_struct *task, struct stack_info *info); int get_stack_info(unsigned long stack, struct task_struct *task, struct stack_info *info); +static __always_inline bool on_thread_stack(void) +{ + return !(((unsigned long)(current->stack) ^ current_stack_pointer) & ~(THREAD_SIZE - 1)); +} + #define STR_LONG_L __stringify(LONG_L) #define STR_LONG_S __stringify(LONG_S) #define STR_LONGSIZE __stringify(LONGSIZE) diff --git a/arch/loongarch/kernel/entry.S b/arch/loongarch/kernel/entry.S index 48e7e34e355e..77f6fb9146a2 100644 --- a/arch/loongarch/kernel/entry.S +++ b/arch/loongarch/kernel/entry.S @@ -73,6 +73,7 @@ SYM_CODE_START(handle_syscall) move a0, sp bl do_syscall + STACKLEAK_ERASE RESTORE_ALL_AND_RET SYM_CODE_END(handle_syscall) _ASM_NOKPROBE(handle_syscall) @@ -82,6 +83,7 @@ SYM_CODE_START(ret_from_fork) bl schedule_tail # a0 = struct task_struct *prev move a0, sp bl syscall_exit_to_user_mode + STACKLEAK_ERASE RESTORE_STATIC RESTORE_SOME RESTORE_SP_AND_RET @@ -94,6 +96,7 @@ SYM_CODE_START(ret_from_kernel_thread) jirl ra, s0, 0 move a0, sp bl syscall_exit_to_user_mode + STACKLEAK_ERASE RESTORE_STATIC RESTORE_SOME RESTORE_SP_AND_RET diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index d23a1b9fed75..b97981d63d2f 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -31,7 +31,7 @@ cflags-$(CONFIG_ARM) += -DEFI_HAVE_STRLEN -DEFI_HAVE_STRNLEN \ $(DISABLE_STACKLEAK_PLUGIN) cflags-$(CONFIG_RISCV) += -fpic -DNO_ALTERNATIVE -mno-relax \ $(DISABLE_STACKLEAK_PLUGIN) -cflags-$(CONFIG_LOONGARCH) += -fpie +cflags-$(CONFIG_LOONGARCH) += -fpie $(DISABLE_STACKLEAK_PLUGIN) cflags-$(CONFIG_EFI_PARAMS_FROM_FDT) += -I$(srctree)/scripts/dtc/libfdt