From: Aleksa Sarai <cyphar@cyphar.com> To: Al Viro <viro@zeniv.linux.org.uk>, Jeff Layton <jlayton@kernel.org>, "J. Bruce Fields" <bfields@fieldses.org>, Arnd Bergmann <arnd@arndb.de>, David Howells <dhowells@redhat.com>, Shuah Khan <shuah@kernel.org>, Shuah Khan <skhan@linuxfoundation.org>, Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>, Alexei Starovoitov <ast@kernel.org>, Daniel Borkmann <daniel@iogearbox.net>, Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>, Andrii Nakryiko <andriin@fb.com>, Jonathan Corbet <corbet@lwn.net> Cc: linux-ia64@vger.kernel.org, linux-doc@vger.kernel.org, Alexander Shishkin <alexander.shishkin@linux.intel.com>, Rasmus Villemoes <linux@rasmusvillemoes.dk>, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, sparclinux@vger.kernel.org, linux-api@vger.kernel.org, Jiri Olsa <jolsa@redhat.com>, linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Tycho Andersen <tycho@tycho.ws>, Aleksa Sarai <asarai@suse.de>, linux-sh@vger.kernel.org, David Drysdale <drysdale@google.com>, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-xtensa@linux-xtensa.org, Kees Cook <keescook@chromium.org>, Jann Horn <jannh@google.com>, linuxppc-dev@lists.ozlabs.org, dev@opencontainers.org, Aleksa Sarai <cyphar@cyphar.com>, Andy Lutomirski <luto@kernel.org>, Namhyung Kim <namhyung@kernel.org>, Andrew Morton <akpm@linux-foundation.org>, Christian Brauner <christian@brauner.io>, libc-alpha@sourceware.org, linux-parisc@vger.kernel.org, linux-m68k@lists.linux-m68k.org, netdev@vger.kernel.org, Chanho Min <chanho.min@lge.com>, Oleg Nesterov <oleg@redhat.com>, Eric Biederman <ebiederm@xmission.com>, linux-alpha@vger.kernel.org, linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org, Linus Torvalds <torvalds@linux-foundation.org>, containers@lists.linux-foundation.org Subject: [PATCH v17 03/13] namei: allow nd_jump_link() to produce errors Date: Sun, 17 Nov 2019 12:17:03 +1100 [thread overview] Message-ID: <20191117011713.13032-4-cyphar@cyphar.com> (raw) In-Reply-To: <20191117011713.13032-1-cyphar@cyphar.com> In preparation for LOOKUP_NO_MAGICLINKS, it's necessary to add the ability for nd_jump_link() to return an error which the corresponding get_link() caller must propogate back up to the VFS. Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> --- fs/namei.c | 3 ++- fs/proc/base.c | 3 +-- fs/proc/namespaces.c | 14 +++++++++----- include/linux/namei.h | 2 +- security/apparmor/apparmorfs.c | 6 ++++-- 5 files changed, 17 insertions(+), 11 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 5a47d9c09581..1024a641f075 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -859,7 +859,7 @@ static int nd_jump_root(struct nameidata *nd) * Helper to directly jump to a known parsed path from ->get_link, * caller must have taken a reference to path beforehand. */ -void nd_jump_link(struct path *path) +int nd_jump_link(struct path *path) { struct nameidata *nd = current->nameidata; path_put(&nd->path); @@ -867,6 +867,7 @@ void nd_jump_link(struct path *path) nd->path = *path; nd->inode = nd->path.dentry->d_inode; nd->flags |= LOOKUP_JUMPED; + return 0; } static inline void put_link(struct nameidata *nd) diff --git a/fs/proc/base.c b/fs/proc/base.c index ebea9501afb8..ee97dd322f3e 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1626,8 +1626,7 @@ static const char *proc_pid_get_link(struct dentry *dentry, if (error) goto out; - nd_jump_link(&path); - return NULL; + error = nd_jump_link(&path); out: return ERR_PTR(error); } diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c index 08dd94df1a66..a8cca516f1a9 100644 --- a/fs/proc/namespaces.c +++ b/fs/proc/namespaces.c @@ -51,11 +51,15 @@ static const char *proc_ns_get_link(struct dentry *dentry, if (!task) return ERR_PTR(-EACCES); - if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { - error = ns_get_path(&ns_path, task, ns_ops); - if (!error) - nd_jump_link(&ns_path); - } + if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) + goto out; + + error = ns_get_path(&ns_path, task, ns_ops); + if (error) + goto out; + + error = nd_jump_link(&ns_path); +out: put_task_struct(task); return ERR_PTR(error); } diff --git a/include/linux/namei.h b/include/linux/namei.h index 397a08ade6a2..758e9b47db6f 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -68,7 +68,7 @@ extern int follow_up(struct path *); extern struct dentry *lock_rename(struct dentry *, struct dentry *); extern void unlock_rename(struct dentry *, struct dentry *); -extern void nd_jump_link(struct path *path); +extern int __must_check nd_jump_link(struct path *path); static inline void nd_terminate_link(void *name, size_t len, size_t maxlen) { diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c index 45d13b6462aa..0b7d6dce6291 100644 --- a/security/apparmor/apparmorfs.c +++ b/security/apparmor/apparmorfs.c @@ -2455,16 +2455,18 @@ static const char *policy_get_link(struct dentry *dentry, { struct aa_ns *ns; struct path path; + int error; if (!dentry) return ERR_PTR(-ECHILD); + ns = aa_get_current_ns(); path.mnt = mntget(aafs_mnt); path.dentry = dget(ns_dir(ns)); - nd_jump_link(&path); + error = nd_jump_link(&path); aa_put_ns(ns); - return NULL; + return ERR_PTR(error); } static int policy_readlink(struct dentry *dentry, char __user *buffer, -- 2.24.0
WARNING: multiple messages have this Message-ID (diff)
From: Aleksa Sarai <cyphar@cyphar.com> To: Al Viro <viro@zeniv.linux.org.uk>, Jeff Layton <jlayton@kernel.org>, "J. Bruce Fields" <bfields@fieldses.org>, Arnd Bergmann <arnd@arndb.de>, David Howells <dhowells@redhat.com>, Shuah Khan <shuah@kernel.org>, Shuah Khan <skhan@linuxfoundation.org>, Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>, Alexei Starovoitov <ast@kernel.org>, Daniel Borkmann <daniel@iogearbox.net>, Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>, Andrii Nakryiko <andriin@fb.com>, Jonathan Corbet <corbet@lwn.net> Cc: Aleksa Sarai <cyphar@cyphar.com>, Eric Biederman <ebiederm@xmission.com>, Andy Lutomirski <luto@kernel.org>, Andrew Morton <akpm@linux-foundation.org>, Kees Cook <keescook@chromium.org>, Jann Horn <jannh@google.com>, Tycho Andersen <tycho@tycho.ws>, David Drysdale <drysdale@google.com>, Chanho Min <chanho.min@lge.com>, Oleg Nesterov <oleg@redhat.com>, Rasmus Villemoes <linux@rasmusvillemoes.dk>, Alexander Shishkin <alexander.shishkin@linux.intel.com>, Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>, Christian Brauner <christian@brauner.io>, Aleksa Sarai <asarai@suse.de>, Linus Torvalds <torvalds@linux-foundation.org>, dev@opencontainers.org, containers@lists.linux-foundation.org, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-alpha@vger.kernel.org, linux-api@vger.kernel.org, libc-alpha@sourceware.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org, sparclinux@vger.kernel.org Subject: [PATCH v17 03/13] namei: allow nd_jump_link() to produce errors Date: Sun, 17 Nov 2019 12:17:03 +1100 [thread overview] Message-ID: <20191117011713.13032-4-cyphar@cyphar.com> (raw) Message-ID: <20191117011703.qX7zfDhAvbutUV4UYCuUjDnFuhkAJrcY8uFkogn-wxM@z> (raw) In-Reply-To: <20191117011713.13032-1-cyphar@cyphar.com> In preparation for LOOKUP_NO_MAGICLINKS, it's necessary to add the ability for nd_jump_link() to return an error which the corresponding get_link() caller must propogate back up to the VFS. Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> --- fs/namei.c | 3 ++- fs/proc/base.c | 3 +-- fs/proc/namespaces.c | 14 +++++++++----- include/linux/namei.h | 2 +- security/apparmor/apparmorfs.c | 6 ++++-- 5 files changed, 17 insertions(+), 11 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 5a47d9c09581..1024a641f075 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -859,7 +859,7 @@ static int nd_jump_root(struct nameidata *nd) * Helper to directly jump to a known parsed path from ->get_link, * caller must have taken a reference to path beforehand. */ -void nd_jump_link(struct path *path) +int nd_jump_link(struct path *path) { struct nameidata *nd = current->nameidata; path_put(&nd->path); @@ -867,6 +867,7 @@ void nd_jump_link(struct path *path) nd->path = *path; nd->inode = nd->path.dentry->d_inode; nd->flags |= LOOKUP_JUMPED; + return 0; } static inline void put_link(struct nameidata *nd) diff --git a/fs/proc/base.c b/fs/proc/base.c index ebea9501afb8..ee97dd322f3e 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1626,8 +1626,7 @@ static const char *proc_pid_get_link(struct dentry *dentry, if (error) goto out; - nd_jump_link(&path); - return NULL; + error = nd_jump_link(&path); out: return ERR_PTR(error); } diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c index 08dd94df1a66..a8cca516f1a9 100644 --- a/fs/proc/namespaces.c +++ b/fs/proc/namespaces.c @@ -51,11 +51,15 @@ static const char *proc_ns_get_link(struct dentry *dentry, if (!task) return ERR_PTR(-EACCES); - if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { - error = ns_get_path(&ns_path, task, ns_ops); - if (!error) - nd_jump_link(&ns_path); - } + if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) + goto out; + + error = ns_get_path(&ns_path, task, ns_ops); + if (error) + goto out; + + error = nd_jump_link(&ns_path); +out: put_task_struct(task); return ERR_PTR(error); } diff --git a/include/linux/namei.h b/include/linux/namei.h index 397a08ade6a2..758e9b47db6f 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -68,7 +68,7 @@ extern int follow_up(struct path *); extern struct dentry *lock_rename(struct dentry *, struct dentry *); extern void unlock_rename(struct dentry *, struct dentry *); -extern void nd_jump_link(struct path *path); +extern int __must_check nd_jump_link(struct path *path); static inline void nd_terminate_link(void *name, size_t len, size_t maxlen) { diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c index 45d13b6462aa..0b7d6dce6291 100644 --- a/security/apparmor/apparmorfs.c +++ b/security/apparmor/apparmorfs.c @@ -2455,16 +2455,18 @@ static const char *policy_get_link(struct dentry *dentry, { struct aa_ns *ns; struct path path; + int error; if (!dentry) return ERR_PTR(-ECHILD); + ns = aa_get_current_ns(); path.mnt = mntget(aafs_mnt); path.dentry = dget(ns_dir(ns)); - nd_jump_link(&path); + error = nd_jump_link(&path); aa_put_ns(ns); - return NULL; + return ERR_PTR(error); } static int policy_readlink(struct dentry *dentry, char __user *buffer, -- 2.24.0
next prev parent reply other threads:[~2019-11-17 1:27 UTC|newest] Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-11-17 1:17 [PATCH v17 00/13] open: introduce openat2(2) syscall Aleksa Sarai 2019-11-17 1:17 ` Aleksa Sarai 2019-11-17 1:17 ` [PATCH v17 01/13] namei: only return -ECHILD from follow_dotdot_rcu() Aleksa Sarai 2019-11-17 1:17 ` Aleksa Sarai 2019-11-17 1:17 ` [PATCH v17 02/13] nsfs: clean-up ns_get_path() signature to return int Aleksa Sarai 2019-11-17 1:17 ` Aleksa Sarai 2019-11-17 1:17 ` Aleksa Sarai [this message] 2019-11-17 1:17 ` [PATCH v17 03/13] namei: allow nd_jump_link() to produce errors Aleksa Sarai 2019-11-17 1:17 ` [PATCH v17 04/13] namei: allow set_root() " Aleksa Sarai 2019-11-17 1:17 ` Aleksa Sarai 2019-11-17 1:17 ` [PATCH v17 05/13] namei: LOOKUP_NO_SYMLINKS: block symlink resolution Aleksa Sarai 2019-11-17 1:17 ` Aleksa Sarai 2019-11-17 1:17 ` [PATCH v17 06/13] namei: LOOKUP_NO_MAGICLINKS: block magic-link resolution Aleksa Sarai 2019-11-17 1:17 ` Aleksa Sarai 2019-11-17 1:17 ` [PATCH v17 07/13] namei: LOOKUP_NO_XDEV: block mountpoint crossing Aleksa Sarai 2019-11-17 1:17 ` Aleksa Sarai 2019-11-17 1:17 ` [PATCH v17 08/13] namei: LOOKUP_BENEATH: O_BENEATH-like scoped resolution Aleksa Sarai 2019-11-17 1:17 ` Aleksa Sarai 2019-11-25 0:26 ` Al Viro 2019-11-25 6:03 ` Aleksa Sarai 2019-11-17 1:17 ` [PATCH v17 09/13] namei: LOOKUP_IN_ROOT: chroot-like " Aleksa Sarai 2019-11-17 1:17 ` Aleksa Sarai 2019-11-17 1:17 ` [PATCH v17 10/13] namei: LOOKUP_{IN_ROOT, BENEATH}: permit limited ".." resolution Aleksa Sarai 2019-11-17 1:17 ` [PATCH v17 10/13] namei: LOOKUP_{IN_ROOT,BENEATH}: " Aleksa Sarai 2019-11-25 0:35 ` Al Viro 2019-11-25 13:21 ` Aleksa Sarai 2019-11-28 10:10 ` Aleksa Sarai 2019-11-17 1:17 ` [PATCH v17 11/13] open: introduce openat2(2) syscall Aleksa Sarai 2019-11-17 1:17 ` Aleksa Sarai 2019-11-25 0:37 ` Al Viro 2019-11-17 1:17 ` [PATCH v17 12/13] selftests: add openat2(2) selftests Aleksa Sarai 2019-11-17 1:17 ` Aleksa Sarai 2019-11-17 1:28 ` [PATCH v17 13/13] Documentation: path-lookup: include new LOOKUP flags Aleksa Sarai 2019-11-17 1:28 ` Aleksa Sarai 2019-11-25 0:39 ` [PATCH v17 00/13] open: introduce openat2(2) syscall Al Viro
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