From: Al Viro <viro@zeniv.linux.org.uk>
To: Aleksa Sarai <cyphar@cyphar.com>
Cc: Song Liu <songliubraving@fb.com>,
linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Alexei Starovoitov <ast@kernel.org>,
linux-kernel@vger.kernel.org, David Howells <dhowells@redhat.com>,
linux-kselftest@vger.kernel.org, sparclinux@vger.kernel.org,
containers@lists.linux-foundation.org,
Christian Brauner <christian.brauner@ubuntu.com>,
linux-api@vger.kernel.org, Shuah Khan <shuah@kernel.org>,
linux-arch@vger.kernel.org, linux-s390@vger.kernel.org,
Tycho Andersen <tycho@tycho.ws>,
Daniel Borkmann <daniel@iogearbox.net>,
Jiri Olsa <jolsa@redhat.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Ingo Molnar <mingo@redhat.com>,
linux-arm-kernel@lists.infradead.org, Yonghong Song <yhs@fb.com>,
linux-mips@vger.kernel.org, Andrii Nakryiko <andriin@fb.com>,
bpf@vger.kernel.org, l
Subject: Re: [PATCH v16 09/12] namei: LOOKUP_{IN_ROOT,BENEATH}: permit limited ".." resolution
Date: Sat, 16 Nov 2019 01:03:27 +0000 [thread overview]
Message-ID: <20191116010327.GZ26530@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20191116002802.6663-10-cyphar@cyphar.com>
On Sat, Nov 16, 2019 at 11:27:59AM +1100, Aleksa Sarai wrote:
> + if (unlikely(nd->flags & LOOKUP_IS_SCOPED)) {
> + bool m_retry = read_seqretry(&mount_lock, nd->m_seq);
> + bool r_retry = read_seqretry(&rename_lock, nd->r_seq);
> +
> + /*
> + * If there was a racing rename or mount along our
> + * path, then we can't be sure that ".." hasn't jumped
> + * above nd->root (and so userspace should retry or use
> + * some fallback).
> + */
> + if (unlikely(m_retry || r_retry))
> + return -EAGAIN;
> + }
> }
> return 0;
Elaborate... Do these boolean variables make any sense now, really?
WARNING: multiple messages have this Message-ID (diff)
From: Al Viro <viro@zeniv.linux.org.uk>
To: Aleksa Sarai <cyphar@cyphar.com>
Cc: Song Liu <songliubraving@fb.com>,
linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Alexei Starovoitov <ast@kernel.org>,
linux-kernel@vger.kernel.org, David Howells <dhowells@redhat.com>,
linux-kselftest@vger.kernel.org, sparclinux@vger.kernel.org,
containers@lists.linux-foundation.org,
Christian Brauner <christian.brauner@ubuntu.com>,
linux-api@vger.kernel.org, Shuah Khan <shuah@kernel.org>,
linux-arch@vger.kernel.org, linux-s390@vger.kernel.org,
Tycho Andersen <tycho@tycho.ws>,
Daniel Borkmann <daniel@iogearbox.net>,
Jiri Olsa <jolsa@redhat.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Ingo Molnar <mingo@redhat.com>,
linux-arm-kernel@lists.infradead.org, Yonghong Song <yhs@fb.com>,
linux-mips@vger.kernel.org, Andrii Nakryiko <andriin@fb.com>,
bpf@vger.kernel.orgl
Subject: Re: [PATCH v16 09/12] namei: LOOKUP_{IN_ROOT,BENEATH}: permit limited ".." resolution
Date: Sat, 16 Nov 2019 01:03:27 +0000 [thread overview]
Message-ID: <20191116010327.GZ26530@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20191116002802.6663-10-cyphar@cyphar.com>
On Sat, Nov 16, 2019 at 11:27:59AM +1100, Aleksa Sarai wrote:
> + if (unlikely(nd->flags & LOOKUP_IS_SCOPED)) {
> + bool m_retry = read_seqretry(&mount_lock, nd->m_seq);
> + bool r_retry = read_seqretry(&rename_lock, nd->r_seq);
> +
> + /*
> + * If there was a racing rename or mount along our
> + * path, then we can't be sure that ".." hasn't jumped
> + * above nd->root (and so userspace should retry or use
> + * some fallback).
> + */
> + if (unlikely(m_retry || r_retry))
> + return -EAGAIN;
> + }
> }
> return 0;
Elaborate... Do these boolean variables make any sense now, really?
WARNING: multiple messages have this Message-ID (diff)
From: Al Viro <viro@zeniv.linux.org.uk>
To: Aleksa Sarai <cyphar@cyphar.com>
Cc: Song Liu <songliubraving@fb.com>,
linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Alexei Starovoitov <ast@kernel.org>,
linux-kernel@vger.kernel.org, David Howells <dhowells@redhat.com>,
linux-kselftest@vger.kernel.org, sparclinux@vger.kernel.org,
containers@lists.linux-foundation.org,
Christian Brauner <christian.brauner@ubuntu.com>,
linux-api@vger.kernel.org, Shuah Khan <shuah@kernel.org>,
linux-arch@vger.kernel.org, linux-s390@vger.kernel.org,
Tycho Andersen <tycho@tycho.ws>,
Daniel Borkmann <daniel@iogearbox.net>,
Jiri Olsa <jolsa@redhat.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Ingo Molnar <mingo@redhat.com>,
linux-arm-kernel@lists.infradead.org, Yonghong Song <yhs@fb.com>,
linux-mips@vger.kernel.org, Andrii Nakryiko <andriin@fb.com>,
bpf@vger.kernel.org, linux-xtensa@linux-xtensa.org,
Kees Cook <keescook@chromium.org>, Arnd Bergmann <arnd@arndb.de>,
Jann Horn <jannh@google.com>,
linuxppc-dev@lists.ozlabs.org, dev@opencontainers.org,
linux-m68k@lists.linux-m68k.org,
Andy Lutomirski <luto@kernel.org>,
Shuah Khan <skhan@linuxfoundation.org>,
Namhyung Kim <namhyung@kernel.org>,
David Drysdale <drysdale@google.com>,
Christian Brauner <christian@brauner.io>,
"J. Bruce Fields" <bfields@fieldses.org>,
libc-alpha@sourceware.org, Aleksa Sarai <asarai@suse.de>,
linux-parisc@vger.kernel.org, netdev@vger.kernel.org,
Chanho Min <chanho.min@lge.com>, Jeff Layton <jlayton@kernel.org>,
Oleg Nesterov <oleg@redhat.com>,
Eric Biederman <ebiederm@xmission.com>,
linux-alpha@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Martin KaFai Lau <kafai@fb.com>
Subject: Re: [PATCH v16 09/12] namei: LOOKUP_{IN_ROOT,BENEATH}: permit limited ".." resolution
Date: Sat, 16 Nov 2019 01:03:27 +0000 [thread overview]
Message-ID: <20191116010327.GZ26530@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20191116002802.6663-10-cyphar@cyphar.com>
On Sat, Nov 16, 2019 at 11:27:59AM +1100, Aleksa Sarai wrote:
> + if (unlikely(nd->flags & LOOKUP_IS_SCOPED)) {
> + bool m_retry = read_seqretry(&mount_lock, nd->m_seq);
> + bool r_retry = read_seqretry(&rename_lock, nd->r_seq);
> +
> + /*
> + * If there was a racing rename or mount along our
> + * path, then we can't be sure that ".." hasn't jumped
> + * above nd->root (and so userspace should retry or use
> + * some fallback).
> + */
> + if (unlikely(m_retry || r_retry))
> + return -EAGAIN;
> + }
> }
> return 0;
Elaborate... Do these boolean variables make any sense now, really?
next prev parent reply other threads:[~2019-11-16 1:03 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-16 0:27 [PATCH v16 00/12] open: introduce openat2(2) syscall Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` [PATCH v16 01/12] nsfs: clean-up ns_get_path() signature to return int Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` [PATCH v16 02/12] namei: allow nd_jump_link() to produce errors Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:37 ` Al Viro
2019-11-16 0:37 ` Al Viro
2019-11-16 0:37 ` Al Viro
2019-11-16 18:09 ` Aleksa Sarai
2019-11-16 18:09 ` Aleksa Sarai
2019-11-16 18:09 ` Aleksa Sarai
2019-11-16 18:09 ` Aleksa Sarai
2019-11-16 18:09 ` Aleksa Sarai
2019-11-16 0:27 ` [PATCH v16 03/12] namei: allow set_root() " Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` [PATCH v16 04/12] namei: LOOKUP_NO_SYMLINKS: block symlink resolution Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` [PATCH v16 05/12] namei: LOOKUP_NO_MAGICLINKS: block magic-link resolution Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` [PATCH v16 06/12] namei: LOOKUP_NO_XDEV: block mountpoint crossing Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 1:01 ` Al Viro
2019-11-16 1:01 ` Al Viro
2019-11-16 1:01 ` Al Viro
2019-11-16 17:24 ` Aleksa Sarai
2019-11-16 17:24 ` Aleksa Sarai
2019-11-16 17:24 ` Aleksa Sarai
2019-11-16 0:27 ` [PATCH v16 07/12] namei: LOOKUP_BENEATH: O_BENEATH-like scoped resolution Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` [PATCH v16 08/12] namei: LOOKUP_IN_ROOT: chroot-like " Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 0:27 ` [PATCH v16 09/12] namei: LOOKUP_{IN_ROOT,BENEATH}: permit limited ".." resolution Aleksa Sarai
2019-11-16 0:27 ` [PATCH v16 09/12] namei: LOOKUP_{IN_ROOT, BENEATH}: " Aleksa Sarai
2019-11-16 0:27 ` [PATCH v16 09/12] namei: LOOKUP_{IN_ROOT,BENEATH}: " Aleksa Sarai
2019-11-16 0:27 ` Aleksa Sarai
2019-11-16 1:03 ` Al Viro [this message]
2019-11-16 1:03 ` Al Viro
2019-11-16 1:03 ` Al Viro
2019-11-16 16:38 ` Aleksa Sarai
2019-11-16 16:38 ` Aleksa Sarai
2019-11-16 16:38 ` Aleksa Sarai
2019-11-16 0:28 ` [PATCH v16 10/12] open: introduce openat2(2) syscall Aleksa Sarai
2019-11-16 0:28 ` Aleksa Sarai
2019-11-16 0:28 ` Aleksa Sarai
2019-11-16 0:28 ` Aleksa Sarai
2019-11-16 0:28 ` [PATCH v16 11/12] selftests: add openat2(2) selftests Aleksa Sarai
2019-11-16 0:28 ` Aleksa Sarai
2019-11-16 0:28 ` Aleksa Sarai
2019-11-16 0:28 ` Aleksa Sarai
2019-11-16 0:28 ` Aleksa Sarai
2019-11-16 0:28 ` [PATCH v16 12/12] Documentation: path-lookup: include new LOOKUP flags Aleksa Sarai
2019-11-16 0:28 ` Aleksa Sarai
2019-11-16 0:28 ` Aleksa Sarai
2019-11-16 0:28 ` Aleksa Sarai
2019-11-16 0:28 ` Aleksa Sarai
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