From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 391F4C6379D for ; Tue, 24 Nov 2020 10:21:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA93120708 for ; Tue, 24 Nov 2020 10:21:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731986AbgKXKUi (ORCPT ); Tue, 24 Nov 2020 05:20:38 -0500 Received: from mx2.suse.de ([195.135.220.15]:40396 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731973AbgKXKUf (ORCPT ); Tue, 24 Nov 2020 05:20:35 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id B8CADAC66; Tue, 24 Nov 2020 10:20:33 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 4B5A51E130F; Tue, 24 Nov 2020 11:20:33 +0100 (CET) Date: Tue, 24 Nov 2020 11:20:33 +0100 From: Jan Kara To: Borislav Petkov Cc: =?utf-8?B?UGF3ZcWC?= Jasiak , Jan Kara , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, x86@kernel.org, Thomas Gleixner , Brian Gerst , Andy Lutomirski Subject: Re: PROBLEM: fanotify_mark EFAULT on x86 Message-ID: <20201124102033.GA19336@quack2.suse.cz> References: <20201101212738.GA16924@gmail.com> <20201102122638.GB23988@quack2.suse.cz> <20201103211747.GA3688@gmail.com> <20201123164622.GJ27294@quack2.suse.cz> <20201123224651.GA27809@gmail.com> <20201124084507.GA4009@zn.tnic> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="OXfL5xGRrasGEqWY" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20201124084507.GA4009@zn.tnic> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --OXfL5xGRrasGEqWY Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit On Tue 24-11-20 09:45:07, Borislav Petkov wrote: > On Mon, Nov 23, 2020 at 11:46:51PM +0100, Paweł Jasiak wrote: > > On 23/11/20, Jan Kara wrote: > > > OK, with a help of Boris Petkov I think I have a fix that looks correct > > > (attach). Can you please try whether it works for you? Thanks! > > > > Unfortunately I am getting a linker error. > > > > ld: arch/x86/entry/syscall_32.o:(.rodata+0x54c): undefined reference to `__ia32_sys_ia32_fanotify_mark' > > Because CONFIG_COMPAT is not set in your .config. > > Jan, look at 121b32a58a3a and especially this hunk > > diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile > index 9b294c13809a..b8f89f78b8cd 100644 > --- a/arch/x86/kernel/Makefile > +++ b/arch/x86/kernel/Makefile > @@ -53,6 +53,8 @@ obj-y += setup.o x86_init.o i8259.o irqinit.o > obj-$(CONFIG_JUMP_LABEL) += jump_label.o > obj-$(CONFIG_IRQ_WORK) += irq_work.o > obj-y += probe_roms.o > +obj-$(CONFIG_X86_32) += sys_ia32.o > +obj-$(CONFIG_IA32_EMULATION) += sys_ia32.o > > how it enables the ia32 syscalls depending on those config items. Now, > you have > > #ifdef CONFIG_COMPAT > -COMPAT_SYSCALL_DEFINE6(fanotify_mark, > +SYSCALL_DEFINE6(ia32_fanotify_mark, > > which is under CONFIG_COMPAT which is not set in Paweł's config. > > config COMPAT > def_bool y > depends on IA32_EMULATION || X86_X32 > > but it depends on those two config items. > > However, it looks to me like ia32_fanotify_mark's definition should be > simply under CONFIG_X86_32 because: > > IA32_EMULATION is 32-bit emulation on 64-bit kernels > X86_X32 is for the x32 ABI Thanks for checking! I didn't realize I needed to change the ifdefs as well (I missed that bit in 121b32a58a3a). So do I understand correctly that whenever the kernel is 64-bit, 64-bit syscall args (e.g. defined as u64) are passed just fine regardless of whether the userspace is 32-bit or not? Also how about other 32-bit archs? Because I now realized that CONFIG_COMPAT as well as the COMPAT_SYSCALL_DEFINE6() is also utilized by other 32-bit archs (I can see a reference to compat_sys_fanotify_mark e.g. in sparc, powerpc, and other args). So I probably need to actually keep that for other archs but do the modification only for x86, don't I? So something like attached patch? Honza -- Jan Kara SUSE Labs, CR --OXfL5xGRrasGEqWY Content-Type: text/x-patch; charset=utf-8 Content-Disposition: attachment; filename="0001-fanotify-Fix-fanotify_mark-on-32-bit-x86.patch" Content-Transfer-Encoding: 8bit >From 20d2ddf37c01e91ca18d415a59b3488a394acd8f Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 23 Nov 2020 17:37:00 +0100 Subject: [PATCH] fanotify: Fix fanotify_mark() on 32-bit x86 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit converting syscalls taking 64-bit arguments to new scheme of compat handlers omitted converting fanotify_mark(2) which then broke the syscall for 32-bit x86 builds. Add missed conversion. It is somewhat cumbersome since we need to keep the original compat handler for all the other 32-bit archs. CC: Brian Gerst Suggested-by: Borislav Petkov Reported-by: Paweł Jasiak Reported-by: Naresh Kamboju Fixes: 121b32a58a3a ("x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments") CC: stable@vger.kernel.org Signed-off-by: Jan Kara --- arch/x86/entry/syscalls/syscall_32.tbl | 2 +- fs/notify/fanotify/fanotify_user.c | 6 +++++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index 0d0667a9fbd7..b2ec6ff88307 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -350,7 +350,7 @@ 336 i386 perf_event_open sys_perf_event_open 337 i386 recvmmsg sys_recvmmsg_time32 compat_sys_recvmmsg_time32 338 i386 fanotify_init sys_fanotify_init -339 i386 fanotify_mark sys_fanotify_mark compat_sys_fanotify_mark +339 i386 fanotify_mark sys_ia32_fanotify_mark 340 i386 prlimit64 sys_prlimit64 341 i386 name_to_handle_at sys_name_to_handle_at 342 i386 open_by_handle_at sys_open_by_handle_at compat_sys_open_by_handle_at diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 3e01d8f2ab90..54a36d4bd116 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -1292,8 +1292,12 @@ SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags, return do_fanotify_mark(fanotify_fd, flags, mask, dfd, pathname); } -#ifdef CONFIG_COMPAT +#if defined(CONFIG_COMPAT) || defined(CONFIG_X86_32) +#ifdef CONFIG_X86_32 +SYSCALL_DEFINE6(ia32_fanotify_mark, +#elif CONFIG_COMPAT COMPAT_SYSCALL_DEFINE6(fanotify_mark, +#endif int, fanotify_fd, unsigned int, flags, __u32, mask0, __u32, mask1, int, dfd, const char __user *, pathname) -- 2.16.4 --OXfL5xGRrasGEqWY--