From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 6D2EE5FF16; Tue, 13 Feb 2024 17:33:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707845584; cv=none; b=D+wEwww/56kUSijk7yQzkO6gkt7qCKMmFnAvv4wTtSFfy9/+uhGurgnrzSEGlj0n4BmCVE/PJ7dFSrzRgaMo+20U+VcrLiRpVADQ2yyDKYp3aBTbglSYACLpAYnpGB/8Ek16zZJZQg1BoPPysQ8BOPjED33EuJiVCJFYkNjlPq0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707845584; c=relaxed/simple; bh=Yh9NIUOXVfUIK3UL4bqOcTeseSkIBlb+oF4kys+5LlU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tThDCZKJaNy05DDHIQNFEHWGe5mRYdUC5sP4H5QIUQMEjoZQV8LPvsKyQ7wOwwPIQ9mM10VxQPjuWVUugoHQmvPNYyCsH26N1m27ZPubnS7sylGpPrd6i5WfowlYvIXXqhWbDCuJv9JgCWis9HRrCex4kcKwBMBW6jie2biPmDU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=PSMEWRG0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="PSMEWRG0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 942D8C433C7; Tue, 13 Feb 2024 17:33:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1707845584; bh=Yh9NIUOXVfUIK3UL4bqOcTeseSkIBlb+oF4kys+5LlU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PSMEWRG0pRIKXVynJliwGcE19nBeB4pBnCohoFTROds1Q8G45E9piO4YibdtT3xtY ouOcdtiwPr2VdSkoeCtmh5cfLCzt81FOp8NVsJ+0gOhODaFQOyc+XPth8Jr7RtEZKx mRnLGJuoisAvlgiALWKeIqZyuRqdhyckWR9P7Pbk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Qiuxu Zhuo , "Borislav Petkov (AMD)" , "Kirill A. Shutemov" , stable@kernel.org Subject: [PATCH 6.6 106/121] x86/lib: Revert to _ASM_EXTABLE_UA() for {get,put}_user() fixups Date: Tue, 13 Feb 2024 18:21:55 +0100 Message-ID: <20240213171856.087052361@linuxfoundation.org> X-Mailer: git-send-email 2.43.1 In-Reply-To: <20240213171852.948844634@linuxfoundation.org> References: <20240213171852.948844634@linuxfoundation.org> User-Agent: quilt/0.67 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-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Qiuxu Zhuo commit 8eed4e00a370b37b4e5985ed983dccedd555ea9d upstream. During memory error injection test on kernels >= v6.4, the kernel panics like below. However, this issue couldn't be reproduced on kernels <= v6.3. mce: [Hardware Error]: CPU 296: Machine Check Exception: f Bank 1: bd80000000100134 mce: [Hardware Error]: RIP 10: {__get_user_nocheck_4+0x6/0x20} mce: [Hardware Error]: TSC 411a93533ed ADDR 346a8730040 MISC 86 mce: [Hardware Error]: PROCESSOR 0:a06d0 TIME 1706000767 SOCKET 1 APIC 211 microcode 80001490 mce: [Hardware Error]: Run the above through 'mcelog --ascii' mce: [Hardware Error]: Machine check: Data load in unrecoverable area of kernel Kernel panic - not syncing: Fatal local machine check The MCA code can recover from an in-kernel #MC if the fixup type is EX_TYPE_UACCESS, explicitly indicating that the kernel is attempting to access userspace memory. However, if the fixup type is EX_TYPE_DEFAULT the only thing that is raised for an in-kernel #MC is a panic. ex_handler_uaccess() would warn if users gave a non-canonical addresses (with bit 63 clear) to {get, put}_user(), which was unexpected. Therefore, commit b19b74bc99b1 ("x86/mm: Rework address range check in get_user() and put_user()") replaced _ASM_EXTABLE_UA() with _ASM_EXTABLE() for {get, put}_user() fixups. However, the new fixup type EX_TYPE_DEFAULT results in a panic. Commit 6014bc27561f ("x86-64: make access_ok() independent of LAM") added the check gp_fault_address_ok() right before the WARN_ONCE() in ex_handler_uaccess() to not warn about non-canonical user addresses due to LAM. With that in place, revert back to _ASM_EXTABLE_UA() for {get,put}_user() exception fixups in order to be able to handle in-kernel MCEs correctly again. [ bp: Massage commit message. ] Fixes: b19b74bc99b1 ("x86/mm: Rework address range check in get_user() and put_user()") Signed-off-by: Qiuxu Zhuo Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Kirill A. Shutemov Cc: Link: https://lore.kernel.org/r/20240129063842.61584-1-qiuxu.zhuo@intel.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/lib/getuser.S | 24 ++++++++++++------------ arch/x86/lib/putuser.S | 20 ++++++++++---------- 2 files changed, 22 insertions(+), 22 deletions(-) --- a/arch/x86/lib/getuser.S +++ b/arch/x86/lib/getuser.S @@ -163,23 +163,23 @@ SYM_CODE_END(__get_user_8_handle_excepti #endif /* get_user */ - _ASM_EXTABLE(1b, __get_user_handle_exception) - _ASM_EXTABLE(2b, __get_user_handle_exception) - _ASM_EXTABLE(3b, __get_user_handle_exception) + _ASM_EXTABLE_UA(1b, __get_user_handle_exception) + _ASM_EXTABLE_UA(2b, __get_user_handle_exception) + _ASM_EXTABLE_UA(3b, __get_user_handle_exception) #ifdef CONFIG_X86_64 - _ASM_EXTABLE(4b, __get_user_handle_exception) + _ASM_EXTABLE_UA(4b, __get_user_handle_exception) #else - _ASM_EXTABLE(4b, __get_user_8_handle_exception) - _ASM_EXTABLE(5b, __get_user_8_handle_exception) + _ASM_EXTABLE_UA(4b, __get_user_8_handle_exception) + _ASM_EXTABLE_UA(5b, __get_user_8_handle_exception) #endif /* __get_user */ - _ASM_EXTABLE(6b, __get_user_handle_exception) - _ASM_EXTABLE(7b, __get_user_handle_exception) - _ASM_EXTABLE(8b, __get_user_handle_exception) + _ASM_EXTABLE_UA(6b, __get_user_handle_exception) + _ASM_EXTABLE_UA(7b, __get_user_handle_exception) + _ASM_EXTABLE_UA(8b, __get_user_handle_exception) #ifdef CONFIG_X86_64 - _ASM_EXTABLE(9b, __get_user_handle_exception) + _ASM_EXTABLE_UA(9b, __get_user_handle_exception) #else - _ASM_EXTABLE(9b, __get_user_8_handle_exception) - _ASM_EXTABLE(10b, __get_user_8_handle_exception) + _ASM_EXTABLE_UA(9b, __get_user_8_handle_exception) + _ASM_EXTABLE_UA(10b, __get_user_8_handle_exception) #endif --- a/arch/x86/lib/putuser.S +++ b/arch/x86/lib/putuser.S @@ -134,15 +134,15 @@ SYM_CODE_START_LOCAL(__put_user_handle_e RET SYM_CODE_END(__put_user_handle_exception) - _ASM_EXTABLE(1b, __put_user_handle_exception) - _ASM_EXTABLE(2b, __put_user_handle_exception) - _ASM_EXTABLE(3b, __put_user_handle_exception) - _ASM_EXTABLE(4b, __put_user_handle_exception) - _ASM_EXTABLE(5b, __put_user_handle_exception) - _ASM_EXTABLE(6b, __put_user_handle_exception) - _ASM_EXTABLE(7b, __put_user_handle_exception) - _ASM_EXTABLE(9b, __put_user_handle_exception) + _ASM_EXTABLE_UA(1b, __put_user_handle_exception) + _ASM_EXTABLE_UA(2b, __put_user_handle_exception) + _ASM_EXTABLE_UA(3b, __put_user_handle_exception) + _ASM_EXTABLE_UA(4b, __put_user_handle_exception) + _ASM_EXTABLE_UA(5b, __put_user_handle_exception) + _ASM_EXTABLE_UA(6b, __put_user_handle_exception) + _ASM_EXTABLE_UA(7b, __put_user_handle_exception) + _ASM_EXTABLE_UA(9b, __put_user_handle_exception) #ifdef CONFIG_X86_32 - _ASM_EXTABLE(8b, __put_user_handle_exception) - _ASM_EXTABLE(10b, __put_user_handle_exception) + _ASM_EXTABLE_UA(8b, __put_user_handle_exception) + _ASM_EXTABLE_UA(10b, __put_user_handle_exception) #endif