This patch set adds execveat(2) for x86, and is derived from Meredydd
Luff's patch from Sept 2012 (https://lkml.org/lkml/2012/9/11/528).
The primary aim of adding an execveat syscall is to allow an
implementation of fexecve(3) that does not rely on the /proc
filesystem, at least for executables (rather than scripts). The
current glibc version of fexecve(3) is implemented via /proc, which
causes problems in sandboxed or otherwise restricted environments.
Given the desire for a /proc-free fexecve() implementation, HPA
suggested (https://lkml.org/lkml/2006/7/11/556) that an execveat(2)
syscall would be an appropriate generalization.
Also, having a new syscall means that it can take a flags argument
without back-compatibility concerns. The current implementation just
defines the AT_EMPTY_PATH and AT_SYMLINK_NOFOLLOW flags, but other
flags could be added in future -- for example, flags for new namespaces
(as suggested at https://lkml.org/lkml/2006/7/11/474).
Related history:
- https://lkml.org/lkml/2006/12/27/123 is an example of someone
realizing that fexecve() is likely to fail in a chroot environment.
- http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=514043 covered
documenting the /proc requirement of fexecve(3) in its manpage, to
"prevent other people from wasting their time".
- https://bugzilla.redhat.com/show_bug.cgi?id=241609 described a
problem where a process that did setuid() could not fexecve()
because it no longer had access to /proc/self/fd; this has since
been fixed.
Changes since v8:
- Split core/fs changes from x86 changes [Thomas Gleixner]
Changes since v7:
- Speculatively wire up sparc version of syscall (untested)
- Fix leak of pathbuf in mainline arm [Oleg Nesterov]
- Add rcu_dereference_raw() on fdt access [sparse kbuild robot]
- Realigned comment [Andrew Morton]
- Merged up to v3.18-rc4
Changes since v6:
- Remove special case for O_PATH file descriptors [Andy Lutomirski]
- Use kasprintf rather than error-prone arithmetic [Kees Cook]
- Add test for long name [Kees Cook]
- Add test for non-executable O_PATH fd [Andy Lutomirski]
Changes since v5:
- Set new flag in bprm->interp_flags for O_CLOEXEC fds, so that binfmts
that invoke an interpreter fail the exec (as they will not be able
to access the invoked file). [Andy Lutomirski]
- Don't truncate long paths. [Andy Lutomirski]
- Commonize code to open the executed file. [Eric W. Biederman]
- Mark O_PATH file descriptors so they cannot be fexecve()ed.
- Make self-test more helpful, and add additional cases:
- file offset non-zero
- binary file without execute bit
- O_CLOEXEC fds
Changes since v4, suggested by Eric W. Biederman:
- Use empty filename with AT_EMPTY_PATH flag rather than NULL
pathname to request fexecve-like behaviour.
- Build pathname as "/dev/fd/<fd>/<filename>" (or "/dev/fd/<fd>")
rather than using d_path().
- Patch against v3.17 (bfe01a5ba249)
Changes since Meredydd's v3 patch:
- Added a selftest.
- Added a man page.
- Left open_exec() signature untouched to reduce patch impact
elsewhere (as suggested by Al Viro).
- Filled in bprm->filename with d_path() into a buffer, to avoid use
of potentially-ephemeral dentry->d_name.
- Patch against v3.14 (455c6fdbd21916).
David Drysdale (4):
syscalls: implement execveat() system call
x86: Hook up execveat system call.
syscalls: add selftest for execveat(2)
sparc: Hook up execveat system call.
arch/sparc/include/uapi/asm/unistd.h | 3 +-
arch/sparc/kernel/systbls_32.S | 1 +
arch/sparc/kernel/systbls_64.S | 2 +
arch/x86/ia32/audit.c | 1 +
arch/x86/ia32/ia32entry.S | 1 +
arch/x86/kernel/audit_64.c | 1 +
arch/x86/kernel/entry_64.S | 28 +++
arch/x86/syscalls/syscall_32.tbl | 1 +
arch/x86/syscalls/syscall_64.tbl | 2 +
arch/x86/um/sys_call_table_64.c | 1 +
fs/binfmt_em86.c | 4 +
fs/binfmt_misc.c | 4 +
fs/binfmt_script.c | 10 +
fs/exec.c | 113 +++++++--
fs/namei.c | 2 +-
include/linux/binfmts.h | 4 +
include/linux/compat.h | 3 +
include/linux/fs.h | 1 +
include/linux/sched.h | 4 +
include/linux/syscalls.h | 5 +
include/uapi/asm-generic/unistd.h | 4 +-
kernel/sys_ni.c | 3 +
lib/audit.c | 3 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/exec/.gitignore | 9 +
tools/testing/selftests/exec/Makefile | 25 ++
tools/testing/selftests/exec/execveat.c | 397 ++++++++++++++++++++++++++++++++
27 files changed, 617 insertions(+), 16 deletions(-)
create mode 100644 tools/testing/selftests/exec/.gitignore
create mode 100644 tools/testing/selftests/exec/Makefile
create mode 100644 tools/testing/selftests/exec/execveat.c
--
2.1.0.rc2.206.gedb03e5
Signed-off-by: David Drysdale <[email protected]>
---
man2/execveat.2 | 153 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 153 insertions(+)
create mode 100644 man2/execveat.2
diff --git a/man2/execveat.2 b/man2/execveat.2
new file mode 100644
index 000000000000..937d79e4c4f0
--- /dev/null
+++ b/man2/execveat.2
@@ -0,0 +1,153 @@
+.\" Copyright (c) 2014 Google, Inc.
+.\"
+.\" %%%LICENSE_START(VERBATIM)
+.\" Permission is granted to make and distribute verbatim copies of this
+.\" manual provided the copyright notice and this permission notice are
+.\" preserved on all copies.
+.\"
+.\" Permission is granted to copy and distribute modified versions of this
+.\" manual under the conditions for verbatim copying, provided that the
+.\" entire resulting derived work is distributed under the terms of a
+.\" permission notice identical to this one.
+.\"
+.\" Since the Linux kernel and libraries are constantly changing, this
+.\" manual page may be incorrect or out-of-date. The author(s) assume no
+.\" responsibility for errors or omissions, or for damages resulting from
+.\" the use of the information contained herein. The author(s) may not
+.\" have taken the same level of care in the production of this manual,
+.\" which is licensed free of charge, as they might when working
+.\" professionally.
+.\"
+.\" Formatted or processed versions of this manual, if unaccompanied by
+.\" the source, must acknowledge the copyright and authors of this work.
+.\" %%%LICENSE_END
+.\"
+.TH EXECVEAT 2 2014-04-02 "Linux" "Linux Programmer's Manual"
+.SH NAME
+execveat \- execute program relative to a directory file descriptor
+.SH SYNOPSIS
+.B #include <unistd.h>
+.sp
+.BI "int execveat(int " fd ", const char *" pathname ","
+.br
+.BI " char *const " argv "[], char *const " envp "[],"
+.br
+.BI " int " flags);
+.SH DESCRIPTION
+The
+.BR execveat ()
+system call executes the program pointed to by the combination of \fIfd\fP and \fIpathname\fP.
+The
+.BR execveat ()
+system call operates in exactly the same way as
+.BR execve (2),
+except for the differences described in this manual page.
+
+If the pathname given in
+.I pathname
+is relative, then it is interpreted relative to the directory
+referred to by the file descriptor
+.I fd
+(rather than relative to the current working directory of
+the calling process, as is done by
+.BR execve (2)
+for a relative pathname).
+
+If
+.I pathname
+is relative and
+.I fd
+is the special value
+.BR AT_FDCWD ,
+then
+.I pathname
+is interpreted relative to the current working
+directory of the calling process (like
+.BR execve (2)).
+
+If
+.I pathname
+is absolute, then
+.I fd
+is ignored.
+
+If
+.I pathname
+is an empty string and the
+.BR AT_EMPTY_PATH
+flag is specified, then the file descriptor
+.I fd
+specifies the file to be executed.
+
+.I flags
+can either be 0, or include the following flags:
+.TP
+.BR AT_EMPTY_PATH
+If
+.I pathname
+is an empty string, operate on the file referred to by
+.IR fd
+(which may have been obtained using the
+.BR open (2)
+.B O_PATH
+flag).
+.TP
+.B AT_SYMLINK_NOFOLLOW
+If the file identified by
+.I fd
+and a non-NULL
+.I pathname
+is a symbolic link, then the call fails with the error
+.BR EINVAL .
+.SH "RETURN VALUE"
+On success,
+.BR execveat ()
+does not return. On error \-1 is returned, and
+.I errno
+is set appropriately.
+.SH ERRORS
+The same errors that occur for
+.BR execve (2)
+can also occur for
+.BR execveat ().
+The following additional errors can occur for
+.BR execveat ():
+.TP
+.B EBADF
+.I fd
+is not a valid file descriptor.
+.TP
+.B ENOENT
+The program identified by \fIfd\fP and \fIpathname\fP requires the
+use of an interpreter program (such as a script starting with
+"#!") but the file descriptor
+.I fd
+was opened with the
+.B O_CLOEXEC
+flag and so the program file is inaccessible to the launched interpreter.
+.TP
+.B EINVAL
+Invalid flag specified in
+.IR flags .
+.TP
+.B ENOTDIR
+.I pathname
+is relative and
+.I fd
+is a file descriptor referring to a file other than a directory.
+.SH VERSIONS
+.BR execveat ()
+was added to Linux in kernel 3.???.
+.SH NOTES
+In addition to the reasons explained in
+.BR openat (2),
+the
+.BR execveat ()
+system call is also needed to allow
+.BR fexecve (3)
+to be implemented on systems that do not have the
+.I /proc
+filesystem mounted.
+.SH SEE ALSO
+.BR execve (2),
+.BR fexecve (3)
--
2.1.0.rc2.206.gedb03e5
Add a new execveat(2) system call. execveat() is to execve() as
openat() is to open(): it takes a file descriptor that refers to a
directory, and resolves the filename relative to that.
In addition, if the filename is empty and AT_EMPTY_PATH is specified,
execveat() executes the file to which the file descriptor refers. This
replicates the functionality of fexecve(), which is a system call in
other UNIXen, but in Linux glibc it depends on opening
"/proc/self/fd/<fd>" (and so relies on /proc being mounted).
The filename fed to the executed program as argv[0] (or the name of the
script fed to a script interpreter) will be of the form "/dev/fd/<fd>"
(for an empty filename) or "/dev/fd/<fd>/<filename>", effectively
reflecting how the executable was found. This does however mean that
execution of a script in a /proc-less environment won't work; also,
script execution via an O_CLOEXEC file descriptor fails (as the file
will not be accessible after exec).
Based on patches by Meredydd Luff <[email protected]>
Signed-off-by: David Drysdale <[email protected]>
---
fs/binfmt_em86.c | 4 ++
fs/binfmt_misc.c | 4 ++
fs/binfmt_script.c | 10 ++++
fs/exec.c | 113 +++++++++++++++++++++++++++++++++-----
fs/namei.c | 2 +-
include/linux/binfmts.h | 4 ++
include/linux/compat.h | 3 +
include/linux/fs.h | 1 +
include/linux/sched.h | 4 ++
include/linux/syscalls.h | 5 ++
include/uapi/asm-generic/unistd.h | 4 +-
kernel/sys_ni.c | 3 +
lib/audit.c | 3 +
13 files changed, 145 insertions(+), 15 deletions(-)
diff --git a/fs/binfmt_em86.c b/fs/binfmt_em86.c
index f37b08cea1f7..490538536cb4 100644
--- a/fs/binfmt_em86.c
+++ b/fs/binfmt_em86.c
@@ -42,6 +42,10 @@ static int load_em86(struct linux_binprm *bprm)
return -ENOEXEC;
}
+ /* Need to be able to load the file after exec */
+ if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE)
+ return -ENOENT;
+
allow_write_access(bprm->file);
fput(bprm->file);
bprm->file = NULL;
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index fd8beb9657a2..85acb8c83a9a 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -142,6 +142,10 @@ static int load_misc_binary(struct linux_binprm *bprm)
if (!fmt)
goto _ret;
+ /* Need to be able to load the file after exec */
+ if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE)
+ return -ENOENT;
+
if (!(fmt->flags & MISC_FMT_PRESERVE_ARGV0)) {
retval = remove_arg_zero(bprm);
if (retval)
diff --git a/fs/binfmt_script.c b/fs/binfmt_script.c
index 5027a3e14922..afdf4e3cafc2 100644
--- a/fs/binfmt_script.c
+++ b/fs/binfmt_script.c
@@ -24,6 +24,16 @@ static int load_script(struct linux_binprm *bprm)
if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!'))
return -ENOEXEC;
+
+ /*
+ * If the script filename will be inaccessible after exec, typically
+ * because it is a "/dev/fd/<fd>/.." path against an O_CLOEXEC fd, give
+ * up now (on the assumption that the interpreter will want to load
+ * this file).
+ */
+ if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE)
+ return -ENOENT;
+
/*
* This section does the #! interpretation.
* Sorta complicated, but hopefully it will work. -TYT
diff --git a/fs/exec.c b/fs/exec.c
index 7302b75a9820..6ce5cc47a201 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -747,18 +747,25 @@ EXPORT_SYMBOL(setup_arg_pages);
#endif /* CONFIG_MMU */
-static struct file *do_open_exec(struct filename *name)
+static struct file *do_open_execat(int fd, struct filename *name, int flags)
{
struct file *file;
int err;
- static const struct open_flags open_exec_flags = {
+ struct open_flags open_exec_flags = {
.open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC,
.acc_mode = MAY_EXEC | MAY_OPEN,
.intent = LOOKUP_OPEN,
.lookup_flags = LOOKUP_FOLLOW,
};
- file = do_filp_open(AT_FDCWD, name, &open_exec_flags);
+ if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0)
+ return ERR_PTR(-EINVAL);
+ if (flags & AT_SYMLINK_NOFOLLOW)
+ open_exec_flags.lookup_flags &= ~LOOKUP_FOLLOW;
+ if (flags & AT_EMPTY_PATH)
+ open_exec_flags.lookup_flags |= LOOKUP_EMPTY;
+
+ file = do_filp_open(fd, name, &open_exec_flags);
if (IS_ERR(file))
goto out;
@@ -769,12 +776,13 @@ static struct file *do_open_exec(struct filename *name)
if (file->f_path.mnt->mnt_flags & MNT_NOEXEC)
goto exit;
- fsnotify_open(file);
-
err = deny_write_access(file);
if (err)
goto exit;
+ if (name->name[0] != '\0')
+ fsnotify_open(file);
+
out:
return file;
@@ -786,7 +794,7 @@ exit:
struct file *open_exec(const char *name)
{
struct filename tmp = { .name = name };
- return do_open_exec(&tmp);
+ return do_open_execat(AT_FDCWD, &tmp, 0);
}
EXPORT_SYMBOL(open_exec);
@@ -1427,10 +1435,12 @@ static int exec_binprm(struct linux_binprm *bprm)
/*
* sys_execve() executes a new program.
*/
-static int do_execve_common(struct filename *filename,
- struct user_arg_ptr argv,
- struct user_arg_ptr envp)
+static int do_execveat_common(int fd, struct filename *filename,
+ struct user_arg_ptr argv,
+ struct user_arg_ptr envp,
+ int flags)
{
+ char *pathbuf = NULL;
struct linux_binprm *bprm;
struct file *file;
struct files_struct *displaced;
@@ -1471,7 +1481,7 @@ static int do_execve_common(struct filename *filename,
check_unsafe_exec(bprm);
current->in_execve = 1;
- file = do_open_exec(filename);
+ file = do_open_execat(fd, filename, flags);
retval = PTR_ERR(file);
if (IS_ERR(file))
goto out_unmark;
@@ -1479,7 +1489,28 @@ static int do_execve_common(struct filename *filename,
sched_exec();
bprm->file = file;
- bprm->filename = bprm->interp = filename->name;
+ if (fd == AT_FDCWD || filename->name[0] == '/') {
+ bprm->filename = filename->name;
+ } else {
+ if (filename->name[0] == '\0')
+ pathbuf = kasprintf(GFP_TEMPORARY, "/dev/fd/%d", fd);
+ else
+ pathbuf = kasprintf(GFP_TEMPORARY, "/dev/fd/%d/%s",
+ fd, filename->name);
+ if (!pathbuf) {
+ retval = -ENOMEM;
+ goto out_unmark;
+ }
+ /*
+ * Record that a name derived from an O_CLOEXEC fd will be
+ * inaccessible after exec. Relies on having exclusive access to
+ * current->files (due to unshare_files above).
+ */
+ if (close_on_exec(fd, rcu_dereference_raw(current->files->fdt)))
+ bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE;
+ bprm->filename = pathbuf;
+ }
+ bprm->interp = bprm->filename;
retval = bprm_mm_init(bprm);
if (retval)
@@ -1520,6 +1551,7 @@ static int do_execve_common(struct filename *filename,
acct_update_integrals(current);
task_numa_free(current);
free_bprm(bprm);
+ kfree(pathbuf);
putname(filename);
if (displaced)
put_files_struct(displaced);
@@ -1537,6 +1569,7 @@ out_unmark:
out_free:
free_bprm(bprm);
+ kfree(pathbuf);
out_files:
if (displaced)
@@ -1552,7 +1585,18 @@ int do_execve(struct filename *filename,
{
struct user_arg_ptr argv = { .ptr.native = __argv };
struct user_arg_ptr envp = { .ptr.native = __envp };
- return do_execve_common(filename, argv, envp);
+ return do_execveat_common(AT_FDCWD, filename, argv, envp, 0);
+}
+
+int do_execveat(int fd, struct filename *filename,
+ const char __user *const __user *__argv,
+ const char __user *const __user *__envp,
+ int flags)
+{
+ struct user_arg_ptr argv = { .ptr.native = __argv };
+ struct user_arg_ptr envp = { .ptr.native = __envp };
+
+ return do_execveat_common(fd, filename, argv, envp, flags);
}
#ifdef CONFIG_COMPAT
@@ -1568,7 +1612,23 @@ static int compat_do_execve(struct filename *filename,
.is_compat = true,
.ptr.compat = __envp,
};
- return do_execve_common(filename, argv, envp);
+ return do_execveat_common(AT_FDCWD, filename, argv, envp, 0);
+}
+
+static int compat_do_execveat(int fd, struct filename *filename,
+ const compat_uptr_t __user *__argv,
+ const compat_uptr_t __user *__envp,
+ int flags)
+{
+ struct user_arg_ptr argv = {
+ .is_compat = true,
+ .ptr.compat = __argv,
+ };
+ struct user_arg_ptr envp = {
+ .is_compat = true,
+ .ptr.compat = __envp,
+ };
+ return do_execveat_common(fd, filename, argv, envp, flags);
}
#endif
@@ -1608,6 +1668,20 @@ SYSCALL_DEFINE3(execve,
{
return do_execve(getname(filename), argv, envp);
}
+
+SYSCALL_DEFINE5(execveat,
+ int, fd, const char __user *, filename,
+ const char __user *const __user *, argv,
+ const char __user *const __user *, envp,
+ int, flags)
+{
+ int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
+
+ return do_execveat(fd,
+ getname_flags(filename, lookup_flags, NULL),
+ argv, envp, flags);
+}
+
#ifdef CONFIG_COMPAT
COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename,
const compat_uptr_t __user *, argv,
@@ -1615,4 +1689,17 @@ COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename,
{
return compat_do_execve(getname(filename), argv, envp);
}
+
+COMPAT_SYSCALL_DEFINE5(execveat, int, fd,
+ const char __user *, filename,
+ const compat_uptr_t __user *, argv,
+ const compat_uptr_t __user *, envp,
+ int, flags)
+{
+ int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
+
+ return compat_do_execveat(fd,
+ getname_flags(filename, lookup_flags, NULL),
+ argv, envp, flags);
+}
#endif
diff --git a/fs/namei.c b/fs/namei.c
index db5fe86319e6..ca814165d84c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -130,7 +130,7 @@ void final_putname(struct filename *name)
#define EMBEDDED_NAME_MAX (PATH_MAX - sizeof(struct filename))
-static struct filename *
+struct filename *
getname_flags(const char __user *filename, int flags, int *empty)
{
struct filename *result, *err;
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index 61f29e5ea840..576e4639ca60 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -53,6 +53,10 @@ struct linux_binprm {
#define BINPRM_FLAGS_EXECFD_BIT 1
#define BINPRM_FLAGS_EXECFD (1 << BINPRM_FLAGS_EXECFD_BIT)
+/* filename of the binary will be inaccessible after exec */
+#define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
+#define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
+
/* Function parameter for binfmt->coredump */
struct coredump_params {
const siginfo_t *siginfo;
diff --git a/include/linux/compat.h b/include/linux/compat.h
index e6494261eaff..7450ca2ac1fc 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -357,6 +357,9 @@ asmlinkage long compat_sys_lseek(unsigned int, compat_off_t, unsigned int);
asmlinkage long compat_sys_execve(const char __user *filename, const compat_uptr_t __user *argv,
const compat_uptr_t __user *envp);
+asmlinkage long compat_sys_execveat(int dfd, const char __user *filename,
+ const compat_uptr_t __user *argv,
+ const compat_uptr_t __user *envp, int flags);
asmlinkage long compat_sys_select(int n, compat_ulong_t __user *inp,
compat_ulong_t __user *outp, compat_ulong_t __user *exp,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9ab779e8a63c..133b60b1d4d0 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2072,6 +2072,7 @@ extern int vfs_open(const struct path *, struct file *, const struct cred *);
extern struct file * dentry_open(const struct path *, int, const struct cred *);
extern int filp_close(struct file *, fl_owner_t id);
+extern struct filename *getname_flags(const char __user *, int, int *);
extern struct filename *getname(const char __user *);
extern struct filename *getname_kernel(const char *);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 5e344bbe63ec..344163d09efb 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2441,6 +2441,10 @@ extern void do_group_exit(int);
extern int do_execve(struct filename *,
const char __user * const __user *,
const char __user * const __user *);
+extern int do_execveat(int, struct filename *,
+ const char __user * const __user *,
+ const char __user * const __user *,
+ int);
extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
struct task_struct *fork_idle(int);
extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index bda9b81357cc..1ff5a4d09693 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -877,4 +877,9 @@ asmlinkage long sys_seccomp(unsigned int op, unsigned int flags,
asmlinkage long sys_getrandom(char __user *buf, size_t count,
unsigned int flags);
asmlinkage long sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
+
+asmlinkage long sys_execveat(int dfd, const char __user *filename,
+ const char __user *const __user *argv,
+ const char __user *const __user *envp, int flags);
+
#endif
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 22749c134117..e016bd9b1a04 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -707,9 +707,11 @@ __SYSCALL(__NR_getrandom, sys_getrandom)
__SYSCALL(__NR_memfd_create, sys_memfd_create)
#define __NR_bpf 280
__SYSCALL(__NR_bpf, sys_bpf)
+#define __NR_execveat 281
+__SC_COMP(__NR_execveat, sys_execveat, compat_sys_execveat)
#undef __NR_syscalls
-#define __NR_syscalls 281
+#define __NR_syscalls 282
/*
* All syscalls below here should go away really,
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 02aa4185b17e..832fba6e2eb1 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -224,3 +224,6 @@ cond_syscall(sys_seccomp);
/* access BPF programs and maps */
cond_syscall(sys_bpf);
+
+/* execveat */
+cond_syscall(sys_execveat);
diff --git a/lib/audit.c b/lib/audit.c
index 1d726a22565b..b8fb5ee81e26 100644
--- a/lib/audit.c
+++ b/lib/audit.c
@@ -54,6 +54,9 @@ int audit_classify_syscall(int abi, unsigned syscall)
case __NR_socketcall:
return 4;
#endif
+#ifdef __NR_execveat
+ case __NR_execveat:
+#endif
case __NR_execve:
return 5;
default:
--
2.1.0.rc2.206.gedb03e5
Signed-off-by: David Drysdale <[email protected]>
Acked-by: David S. Miller <[email protected]>
---
arch/sparc/include/uapi/asm/unistd.h | 3 ++-
arch/sparc/kernel/systbls_32.S | 1 +
arch/sparc/kernel/systbls_64.S | 2 ++
3 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/sparc/include/uapi/asm/unistd.h b/arch/sparc/include/uapi/asm/unistd.h
index 46d83842eddc..6f35f4df17f2 100644
--- a/arch/sparc/include/uapi/asm/unistd.h
+++ b/arch/sparc/include/uapi/asm/unistd.h
@@ -415,8 +415,9 @@
#define __NR_getrandom 347
#define __NR_memfd_create 348
#define __NR_bpf 349
+#define __NR_execveat 350
-#define NR_syscalls 350
+#define NR_syscalls 351
/* Bitmask values returned from kern_features system call. */
#define KERN_FEATURE_MIXED_MODE_STACK 0x00000001
diff --git a/arch/sparc/kernel/systbls_32.S b/arch/sparc/kernel/systbls_32.S
index ad0cdf497b78..e31a9056a303 100644
--- a/arch/sparc/kernel/systbls_32.S
+++ b/arch/sparc/kernel/systbls_32.S
@@ -87,3 +87,4 @@ sys_call_table:
/*335*/ .long sys_syncfs, sys_sendmmsg, sys_setns, sys_process_vm_readv, sys_process_vm_writev
/*340*/ .long sys_ni_syscall, sys_kcmp, sys_finit_module, sys_sched_setattr, sys_sched_getattr
/*345*/ .long sys_renameat2, sys_seccomp, sys_getrandom, sys_memfd_create, sys_bpf
+/*350*/ .long sys_execveat
diff --git a/arch/sparc/kernel/systbls_64.S b/arch/sparc/kernel/systbls_64.S
index 580cde9370c9..15069cb35dac 100644
--- a/arch/sparc/kernel/systbls_64.S
+++ b/arch/sparc/kernel/systbls_64.S
@@ -88,6 +88,7 @@ sys_call_table32:
.word sys_syncfs, compat_sys_sendmmsg, sys_setns, compat_sys_process_vm_readv, compat_sys_process_vm_writev
/*340*/ .word sys_kern_features, sys_kcmp, sys_finit_module, sys_sched_setattr, sys_sched_getattr
.word sys32_renameat2, sys_seccomp, sys_getrandom, sys_memfd_create, sys_bpf
+/*350*/ .word sys_execveat
#endif /* CONFIG_COMPAT */
@@ -167,3 +168,4 @@ sys_call_table:
.word sys_syncfs, sys_sendmmsg, sys_setns, sys_process_vm_readv, sys_process_vm_writev
/*340*/ .word sys_kern_features, sys_kcmp, sys_finit_module, sys_sched_setattr, sys_sched_getattr
.word sys_renameat2, sys_seccomp, sys_getrandom, sys_memfd_create, sys_bpf
+/*350*/ .word sys_execveat
--
2.1.0.rc2.206.gedb03e5
Signed-off-by: David Drysdale <[email protected]>
---
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/exec/.gitignore | 9 +
tools/testing/selftests/exec/Makefile | 25 ++
tools/testing/selftests/exec/execveat.c | 397 ++++++++++++++++++++++++++++++++
4 files changed, 432 insertions(+)
create mode 100644 tools/testing/selftests/exec/.gitignore
create mode 100644 tools/testing/selftests/exec/Makefile
create mode 100644 tools/testing/selftests/exec/execveat.c
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 45f145c6f843..c14893b501a9 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -15,6 +15,7 @@ TARGETS += user
TARGETS += sysctl
TARGETS += firmware
TARGETS += ftrace
+TARGETS += exec
TARGETS_HOTPLUG = cpu-hotplug
TARGETS_HOTPLUG += memory-hotplug
diff --git a/tools/testing/selftests/exec/.gitignore b/tools/testing/selftests/exec/.gitignore
new file mode 100644
index 000000000000..64073e050c6a
--- /dev/null
+++ b/tools/testing/selftests/exec/.gitignore
@@ -0,0 +1,9 @@
+subdir*
+script*
+execveat
+execveat.symlink
+execveat.moved
+execveat.path.ephemeral
+execveat.ephemeral
+execveat.denatured
+xxxxxxxx*
\ No newline at end of file
diff --git a/tools/testing/selftests/exec/Makefile b/tools/testing/selftests/exec/Makefile
new file mode 100644
index 000000000000..66dfc2ce1788
--- /dev/null
+++ b/tools/testing/selftests/exec/Makefile
@@ -0,0 +1,25 @@
+CC = $(CROSS_COMPILE)gcc
+CFLAGS = -Wall
+BINARIES = execveat
+DEPS = execveat.symlink execveat.denatured script subdir
+all: $(BINARIES) $(DEPS)
+
+subdir:
+ mkdir -p $@
+script:
+ echo '#!/bin/sh' > $@
+ echo 'exit $$*' >> $@
+ chmod +x $@
+execveat.symlink: execveat
+ ln -s -f $< $@
+execveat.denatured: execveat
+ cp $< $@
+ chmod -x $@
+%: %.c
+ $(CC) $(CFLAGS) -o $@ $^
+
+run_tests: all
+ ./execveat
+
+clean:
+ rm -rf $(BINARIES) $(DEPS) subdir.moved execveat.moved xxxxx*
diff --git a/tools/testing/selftests/exec/execveat.c b/tools/testing/selftests/exec/execveat.c
new file mode 100644
index 000000000000..33a5c06d95ca
--- /dev/null
+++ b/tools/testing/selftests/exec/execveat.c
@@ -0,0 +1,397 @@
+/*
+ * Copyright (c) 2014 Google, Inc.
+ *
+ * Licensed under the terms of the GNU GPL License version 2
+ *
+ * Selftests for execveat(2).
+ */
+
+#define _GNU_SOURCE /* to get O_PATH, AT_EMPTY_PATH */
+#include <sys/sendfile.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+static char longpath[2 * PATH_MAX] = "";
+static char *envp[] = { "IN_TEST=yes", NULL, NULL };
+static char *argv[] = { "execveat", "99", NULL };
+
+static int execveat_(int fd, const char *path, char **argv, char **envp,
+ int flags)
+{
+#ifdef __NR_execveat
+ return syscall(__NR_execveat, fd, path, argv, envp, flags);
+#else
+ errno = -ENOSYS;
+ return -1;
+#endif
+}
+
+#define check_execveat_fail(fd, path, flags, errno) \
+ _check_execveat_fail(fd, path, flags, errno, #errno)
+static int _check_execveat_fail(int fd, const char *path, int flags,
+ int expected_errno, const char *errno_str)
+{
+ int rc;
+
+ errno = 0;
+ printf("Check failure of execveat(%d, '%s', %d) with %s... ",
+ fd, path?:"(null)", flags, errno_str);
+ rc = execveat_(fd, path, argv, envp, flags);
+
+ if (rc > 0) {
+ printf("[FAIL] (unexpected success from execveat(2))\n");
+ return 1;
+ }
+ if (errno != expected_errno) {
+ printf("[FAIL] (expected errno %d (%s) not %d (%s)\n",
+ expected_errno, strerror(expected_errno),
+ errno, strerror(errno));
+ return 1;
+ }
+ printf("[OK]\n");
+ return 0;
+}
+
+static int check_execveat_invoked_rc(int fd, const char *path, int flags,
+ int expected_rc)
+{
+ int status;
+ int rc;
+ pid_t child;
+ int pathlen = path ? strlen(path) : 0;
+
+ if (pathlen > 40)
+ printf("Check success of execveat(%d, '%.20s...%s', %d)... ",
+ fd, path, (path + pathlen - 20), flags);
+ else
+ printf("Check success of execveat(%d, '%s', %d)... ",
+ fd, path?:"(null)", flags);
+ child = fork();
+ if (child < 0) {
+ printf("[FAIL] (fork() failed)\n");
+ return 1;
+ }
+ if (child == 0) {
+ /* Child: do execveat(). */
+ rc = execveat_(fd, path, argv, envp, flags);
+ printf("[FAIL]: execveat() failed, rc=%d errno=%d (%s)\n",
+ rc, errno, strerror(errno));
+ exit(1); /* should not reach here */
+ }
+ /* Parent: wait for & check child's exit status. */
+ rc = waitpid(child, &status, 0);
+ if (rc != child) {
+ printf("[FAIL] (waitpid(%d,...) returned %d)\n", child, rc);
+ return 1;
+ }
+ if (!WIFEXITED(status)) {
+ printf("[FAIL] (child %d did not exit cleanly, status=%08x)\n",
+ child, status);
+ return 1;
+ }
+ if (WEXITSTATUS(status) != expected_rc) {
+ printf("[FAIL] (child %d exited with %d not %d)\n",
+ child, WEXITSTATUS(status), expected_rc);
+ return 1;
+ }
+ printf("[OK]\n");
+ return 0;
+}
+
+static int check_execveat(int fd, const char *path, int flags)
+{
+ return check_execveat_invoked_rc(fd, path, flags, 99);
+}
+
+static char *concat(const char *left, const char *right)
+{
+ char *result = malloc(strlen(left) + strlen(right) + 1);
+
+ strcpy(result, left);
+ strcat(result, right);
+ return result;
+}
+
+static int open_or_die(const char *filename, int flags)
+{
+ int fd = open(filename, flags);
+
+ if (fd < 0) {
+ printf("Failed to open '%s'; "
+ "check prerequisites are available\n", filename);
+ exit(1);
+ }
+ return fd;
+}
+
+static void exe_cp(const char *src, const char *dest)
+{
+ int in_fd = open_or_die(src, O_RDONLY);
+ int out_fd = open(dest, O_RDWR|O_CREAT|O_TRUNC, 0755);
+ struct stat info;
+
+ fstat(in_fd, &info);
+ sendfile(out_fd, in_fd, NULL, info.st_size);
+ close(in_fd);
+ close(out_fd);
+}
+
+#define XX_DIR_LEN 200
+static int check_execveat_pathmax(int dot_dfd, const char *src, int is_script)
+{
+ int fail = 0;
+ int ii, count, len;
+ char longname[XX_DIR_LEN + 1];
+ int fd;
+
+ if (*longpath == '\0') {
+ /* Create a filename close to PATH_MAX in length */
+ memset(longname, 'x', XX_DIR_LEN - 1);
+ longname[XX_DIR_LEN - 1] = '/';
+ longname[XX_DIR_LEN] = '\0';
+ count = (PATH_MAX - 3) / XX_DIR_LEN;
+ for (ii = 0; ii < count; ii++) {
+ strcat(longpath, longname);
+ mkdir(longpath, 0755);
+ }
+ len = (PATH_MAX - 3) - (count * XX_DIR_LEN);
+ if (len <= 0)
+ len = 1;
+ memset(longname, 'y', len);
+ longname[len] = '\0';
+ strcat(longpath, longname);
+ }
+ exe_cp(src, longpath);
+
+ /*
+ * Execute as a pre-opened file descriptor, which works whether this is
+ * a script or not (because the interpreter sees a filename like
+ * "/dev/fd/20").
+ */
+ fd = open(longpath, O_RDONLY);
+ if (fd > 0) {
+ printf("Invoke copy of '%s' via filename of length %lu:\n",
+ src, strlen(longpath));
+ fail += check_execveat(fd, "", AT_EMPTY_PATH);
+ } else {
+ printf("Failed to open length %lu filename, errno=%d (%s)\n",
+ strlen(longpath), errno, strerror(errno));
+ fail++;
+ }
+
+ /*
+ * Execute as a long pathname relative to ".". If this is a script,
+ * the interpreter will launch but fail to open the script because its
+ * name ("/dev/fd/5/xxx....") is bigger than PATH_MAX.
+ */
+ if (is_script)
+ fail += check_execveat_invoked_rc(dot_dfd, longpath, 0, 127);
+ else
+ fail += check_execveat(dot_dfd, longpath, 0);
+
+ return fail;
+}
+
+static int run_tests(void)
+{
+ int fail = 0;
+ char *fullname = realpath("execveat", NULL);
+ char *fullname_script = realpath("script", NULL);
+ char *fullname_symlink = concat(fullname, ".symlink");
+ int subdir_dfd = open_or_die("subdir", O_DIRECTORY|O_RDONLY);
+ int subdir_dfd_ephemeral = open_or_die("subdir.ephemeral",
+ O_DIRECTORY|O_RDONLY);
+ int dot_dfd = open_or_die(".", O_DIRECTORY|O_RDONLY);
+ int dot_dfd_path = open_or_die(".", O_DIRECTORY|O_RDONLY|O_PATH);
+ int dot_dfd_cloexec = open_or_die(".", O_DIRECTORY|O_RDONLY|O_CLOEXEC);
+ int fd = open_or_die("execveat", O_RDONLY);
+ int fd_path = open_or_die("execveat", O_RDONLY|O_PATH);
+ int fd_symlink = open_or_die("execveat.symlink", O_RDONLY);
+ int fd_denatured = open_or_die("execveat.denatured", O_RDONLY);
+ int fd_denatured_path = open_or_die("execveat.denatured",
+ O_RDONLY|O_PATH);
+ int fd_script = open_or_die("script", O_RDONLY);
+ int fd_ephemeral = open_or_die("execveat.ephemeral", O_RDONLY);
+ int fd_ephemeral_path = open_or_die("execveat.path.ephemeral",
+ O_RDONLY|O_PATH);
+ int fd_script_ephemeral = open_or_die("script.ephemeral", O_RDONLY);
+ int fd_cloexec = open_or_die("execveat", O_RDONLY|O_CLOEXEC);
+ int fd_script_cloexec = open_or_die("script", O_RDONLY|O_CLOEXEC);
+
+ /* Change file position to confirm it doesn't affect anything */
+ lseek(fd, 10, SEEK_SET);
+
+ /* Normal executable file: */
+ /* dfd + path */
+ fail += check_execveat(subdir_dfd, "../execveat", 0);
+ fail += check_execveat(dot_dfd, "execveat", 0);
+ fail += check_execveat(dot_dfd_path, "execveat", 0);
+ /* absolute path */
+ fail += check_execveat(AT_FDCWD, fullname, 0);
+ /* absolute path with nonsense dfd */
+ fail += check_execveat(99, fullname, 0);
+ /* fd + no path */
+ fail += check_execveat(fd, "", AT_EMPTY_PATH);
+ /* O_CLOEXEC fd + no path */
+ fail += check_execveat(fd_cloexec, "", AT_EMPTY_PATH);
+ /* O_PATH fd */
+ fail += check_execveat(fd_path, "", AT_EMPTY_PATH);
+
+ /* Mess with executable file that's already open: */
+ /* fd + no path to a file that's been renamed */
+ rename("execveat.ephemeral", "execveat.moved");
+ fail += check_execveat(fd_ephemeral, "", AT_EMPTY_PATH);
+ /* fd + no path to a file that's been deleted */
+ unlink("execveat.moved"); /* remove the file now fd open */
+ fail += check_execveat(fd_ephemeral, "", AT_EMPTY_PATH);
+
+ /* Mess with executable file that's already open with O_PATH */
+ /* fd + no path to a file that's been deleted */
+ unlink("execveat.path.ephemeral");
+ fail += check_execveat(fd_ephemeral_path, "", AT_EMPTY_PATH);
+
+ /* Invalid argument failures */
+ fail += check_execveat_fail(fd, "", 0, ENOENT);
+ fail += check_execveat_fail(fd, NULL, AT_EMPTY_PATH, EFAULT);
+
+ /* Symlink to executable file: */
+ /* dfd + path */
+ fail += check_execveat(dot_dfd, "execveat.symlink", 0);
+ fail += check_execveat(dot_dfd_path, "execveat.symlink", 0);
+ /* absolute path */
+ fail += check_execveat(AT_FDCWD, fullname_symlink, 0);
+ /* fd + no path, even with AT_SYMLINK_NOFOLLOW (already followed) */
+ fail += check_execveat(fd_symlink, "", AT_EMPTY_PATH);
+ fail += check_execveat(fd_symlink, "",
+ AT_EMPTY_PATH|AT_SYMLINK_NOFOLLOW);
+
+ /* Symlink fails when AT_SYMLINK_NOFOLLOW set: */
+ /* dfd + path */
+ fail += check_execveat_fail(dot_dfd, "execveat.symlink",
+ AT_SYMLINK_NOFOLLOW, ELOOP);
+ fail += check_execveat_fail(dot_dfd_path, "execveat.symlink",
+ AT_SYMLINK_NOFOLLOW, ELOOP);
+ /* absolute path */
+ fail += check_execveat_fail(AT_FDCWD, fullname_symlink,
+ AT_SYMLINK_NOFOLLOW, ELOOP);
+
+ /* Shell script wrapping executable file: */
+ /* dfd + path */
+ fail += check_execveat(subdir_dfd, "../script", 0);
+ fail += check_execveat(dot_dfd, "script", 0);
+ fail += check_execveat(dot_dfd_path, "script", 0);
+ /* absolute path */
+ fail += check_execveat(AT_FDCWD, fullname_script, 0);
+ /* fd + no path */
+ fail += check_execveat(fd_script, "", AT_EMPTY_PATH);
+ fail += check_execveat(fd_script, "",
+ AT_EMPTY_PATH|AT_SYMLINK_NOFOLLOW);
+ /* O_CLOEXEC fd fails for a script (as script file inaccessible) */
+ fail += check_execveat_fail(fd_script_cloexec, "", AT_EMPTY_PATH,
+ ENOENT);
+ fail += check_execveat_fail(dot_dfd_cloexec, "script", 0, ENOENT);
+
+ /* Mess with script file that's already open: */
+ /* fd + no path to a file that's been renamed */
+ rename("script.ephemeral", "script.moved");
+ fail += check_execveat(fd_script_ephemeral, "", AT_EMPTY_PATH);
+ /* fd + no path to a file that's been deleted */
+ unlink("script.moved"); /* remove the file while fd open */
+ fail += check_execveat(fd_script_ephemeral, "", AT_EMPTY_PATH);
+
+ /* Rename a subdirectory in the path: */
+ rename("subdir.ephemeral", "subdir.moved");
+ fail += check_execveat(subdir_dfd_ephemeral, "../script", 0);
+ fail += check_execveat(subdir_dfd_ephemeral, "script", 0);
+ /* Remove the subdir and its contents */
+ unlink("subdir.moved/script");
+ unlink("subdir.moved");
+ /* Shell loads via deleted subdir OK because name starts with .. */
+ fail += check_execveat(subdir_dfd_ephemeral, "../script", 0);
+ fail += check_execveat_fail(subdir_dfd_ephemeral, "script", 0, ENOENT);
+
+ /* Flag values other than AT_SYMLINK_NOFOLLOW => EINVAL */
+ fail += check_execveat_fail(dot_dfd, "execveat", 0xFFFF, EINVAL);
+ /* Invalid path => ENOENT */
+ fail += check_execveat_fail(dot_dfd, "no-such-file", 0, ENOENT);
+ fail += check_execveat_fail(dot_dfd_path, "no-such-file", 0, ENOENT);
+ fail += check_execveat_fail(AT_FDCWD, "no-such-file", 0, ENOENT);
+ /* Attempt to execute directory => EACCES */
+ fail += check_execveat_fail(dot_dfd, "", AT_EMPTY_PATH, EACCES);
+ /* Attempt to execute non-executable => EACCES */
+ fail += check_execveat_fail(dot_dfd, "Makefile", 0, EACCES);
+ fail += check_execveat_fail(fd_denatured, "", AT_EMPTY_PATH, EACCES);
+ fail += check_execveat_fail(fd_denatured_path, "", AT_EMPTY_PATH,
+ EACCES);
+ /* Attempt to execute nonsense FD => EBADF */
+ fail += check_execveat_fail(99, "", AT_EMPTY_PATH, EBADF);
+ fail += check_execveat_fail(99, "execveat", 0, EBADF);
+ /* Attempt to execute relative to non-directory => ENOTDIR */
+ fail += check_execveat_fail(fd, "execveat", 0, ENOTDIR);
+
+ fail += check_execveat_pathmax(dot_dfd, "execveat", 0);
+ fail += check_execveat_pathmax(dot_dfd, "script", 1);
+ return fail;
+}
+
+static void prerequisites(void)
+{
+ int fd;
+ const char *script = "#!/bin/sh\nexit $*\n";
+
+ /* Create ephemeral copies of files */
+ exe_cp("execveat", "execveat.ephemeral");
+ exe_cp("execveat", "execveat.path.ephemeral");
+ exe_cp("script", "script.ephemeral");
+ mkdir("subdir.ephemeral", 0755);
+
+ fd = open("subdir.ephemeral/script", O_RDWR|O_CREAT|O_TRUNC, 0755);
+ write(fd, script, strlen(script));
+ close(fd);
+}
+
+int main(int argc, char **argv)
+{
+ int ii;
+ int rc;
+ const char *verbose = getenv("VERBOSE");
+
+ if (argc >= 2) {
+ /* If we are invoked with an argument, don't run tests. */
+ const char *in_test = getenv("IN_TEST");
+
+ if (verbose) {
+ printf(" invoked with:");
+ for (ii = 0; ii < argc; ii++)
+ printf(" [%d]='%s'", ii, argv[ii]);
+ printf("\n");
+ }
+
+ /* Check expected environment transferred. */
+ if (!in_test || strcmp(in_test, "yes") != 0) {
+ printf("[FAIL] (no IN_TEST=yes in env)\n");
+ return 1;
+ }
+
+ /* Use the final argument as an exit code. */
+ rc = atoi(argv[argc - 1]);
+ fflush(stdout);
+ } else {
+ prerequisites();
+ if (verbose)
+ envp[1] = "VERBOSE=1";
+ rc = run_tests();
+ if (rc > 0)
+ printf("%d tests failed\n", rc);
+ }
+ return rc;
+}
--
2.1.0.rc2.206.gedb03e5
Hook up x86-64, i386 and x32 ABIs.
Signed-off-by: David Drysdale <[email protected]>
---
arch/x86/ia32/audit.c | 1 +
arch/x86/ia32/ia32entry.S | 1 +
arch/x86/kernel/audit_64.c | 1 +
arch/x86/kernel/entry_64.S | 28 ++++++++++++++++++++++++++++
arch/x86/syscalls/syscall_32.tbl | 1 +
arch/x86/syscalls/syscall_64.tbl | 2 ++
arch/x86/um/sys_call_table_64.c | 1 +
7 files changed, 35 insertions(+)
diff --git a/arch/x86/ia32/audit.c b/arch/x86/ia32/audit.c
index 5d7b381da692..2eccc8932ae6 100644
--- a/arch/x86/ia32/audit.c
+++ b/arch/x86/ia32/audit.c
@@ -35,6 +35,7 @@ int ia32_classify_syscall(unsigned syscall)
case __NR_socketcall:
return 4;
case __NR_execve:
+ case __NR_execveat:
return 5;
default:
return 1;
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index ffe71228fc10..82e8a1d44658 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -480,6 +480,7 @@ GLOBAL(\label)
PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn
PTREGSCALL stub32_sigreturn, sys32_sigreturn
PTREGSCALL stub32_execve, compat_sys_execve
+ PTREGSCALL stub32_execveat, compat_sys_execveat
PTREGSCALL stub32_fork, sys_fork
PTREGSCALL stub32_vfork, sys_vfork
diff --git a/arch/x86/kernel/audit_64.c b/arch/x86/kernel/audit_64.c
index 06d3e5a14d9d..f3672508b249 100644
--- a/arch/x86/kernel/audit_64.c
+++ b/arch/x86/kernel/audit_64.c
@@ -50,6 +50,7 @@ int audit_classify_syscall(int abi, unsigned syscall)
case __NR_openat:
return 3;
case __NR_execve:
+ case __NR_execveat:
return 5;
default:
return 0;
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index df088bb03fb3..40d893c60fcc 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -652,6 +652,20 @@ ENTRY(stub_execve)
CFI_ENDPROC
END(stub_execve)
+ENTRY(stub_execveat)
+ CFI_STARTPROC
+ addq $8, %rsp
+ PARTIAL_FRAME 0
+ SAVE_REST
+ FIXUP_TOP_OF_STACK %r11
+ call sys_execveat
+ RESTORE_TOP_OF_STACK %r11
+ movq %rax,RAX(%rsp)
+ RESTORE_REST
+ jmp int_ret_from_sys_call
+ CFI_ENDPROC
+END(stub_execveat)
+
/*
* sigreturn is special because it needs to restore all registers on return.
* This cannot be done with SYSRET, so use the IRET return path instead.
@@ -697,6 +711,20 @@ ENTRY(stub_x32_execve)
CFI_ENDPROC
END(stub_x32_execve)
+ENTRY(stub_x32_execveat)
+ CFI_STARTPROC
+ addq $8, %rsp
+ PARTIAL_FRAME 0
+ SAVE_REST
+ FIXUP_TOP_OF_STACK %r11
+ call compat_sys_execveat
+ RESTORE_TOP_OF_STACK %r11
+ movq %rax,RAX(%rsp)
+ RESTORE_REST
+ jmp int_ret_from_sys_call
+ CFI_ENDPROC
+END(stub_x32_execveat)
+
#endif
/*
diff --git a/arch/x86/syscalls/syscall_32.tbl b/arch/x86/syscalls/syscall_32.tbl
index 9fe1b5d002f0..b3560ece1c9f 100644
--- a/arch/x86/syscalls/syscall_32.tbl
+++ b/arch/x86/syscalls/syscall_32.tbl
@@ -364,3 +364,4 @@
355 i386 getrandom sys_getrandom
356 i386 memfd_create sys_memfd_create
357 i386 bpf sys_bpf
+358 i386 execveat sys_execveat stub32_execveat
diff --git a/arch/x86/syscalls/syscall_64.tbl b/arch/x86/syscalls/syscall_64.tbl
index 281150b539a2..8d656fbb57aa 100644
--- a/arch/x86/syscalls/syscall_64.tbl
+++ b/arch/x86/syscalls/syscall_64.tbl
@@ -328,6 +328,7 @@
319 common memfd_create sys_memfd_create
320 common kexec_file_load sys_kexec_file_load
321 common bpf sys_bpf
+322 64 execveat stub_execveat
#
# x32-specific system call numbers start at 512 to avoid cache impact
@@ -366,3 +367,4 @@
542 x32 getsockopt compat_sys_getsockopt
543 x32 io_setup compat_sys_io_setup
544 x32 io_submit compat_sys_io_submit
+545 x32 execveat stub_x32_execveat
diff --git a/arch/x86/um/sys_call_table_64.c b/arch/x86/um/sys_call_table_64.c
index f2f0723070ca..20c3649d0691 100644
--- a/arch/x86/um/sys_call_table_64.c
+++ b/arch/x86/um/sys_call_table_64.c
@@ -31,6 +31,7 @@
#define stub_fork sys_fork
#define stub_vfork sys_vfork
#define stub_execve sys_execve
+#define stub_execveat sys_execveat
#define stub_rt_sigreturn sys_rt_sigreturn
#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym, compat)
--
2.1.0.rc2.206.gedb03e5
Hi David,
On Wed, 19 Nov 2014 17:27:51 +0000 David Drysdale <[email protected]> wrote:
>
> diff --git a/arch/sparc/kernel/systbls_64.S b/arch/sparc/kernel/systbls_64.S
> index 580cde9370c9..15069cb35dac 100644
> --- a/arch/sparc/kernel/systbls_64.S
> +++ b/arch/sparc/kernel/systbls_64.S
> @@ -88,6 +88,7 @@ sys_call_table32:
> .word sys_syncfs, compat_sys_sendmmsg, sys_setns, compat_sys_process_vm_readv, compat_sys_process_vm_writev
> /*340*/ .word sys_kern_features, sys_kcmp, sys_finit_module, sys_sched_setattr, sys_sched_getattr
> .word sys32_renameat2, sys_seccomp, sys_getrandom, sys_memfd_create, sys_bpf
> +/*350*/ .word sys_execveat
Shouldn't this be compat_sys_execveat?
>
> #endif /* CONFIG_COMPAT */
--
Cheers,
Stephen Rothwell [email protected]
On Wed, Nov 19, 2014 at 11:42 PM, Stephen Rothwell <[email protected]> wrote:
> Hi David,
>
> On Wed, 19 Nov 2014 17:27:51 +0000 David Drysdale <[email protected]> wrote:
>>
>> diff --git a/arch/sparc/kernel/systbls_64.S b/arch/sparc/kernel/systbls_64.S
>> index 580cde9370c9..15069cb35dac 100644
>> --- a/arch/sparc/kernel/systbls_64.S
>> +++ b/arch/sparc/kernel/systbls_64.S
>> @@ -88,6 +88,7 @@ sys_call_table32:
>> .word sys_syncfs, compat_sys_sendmmsg, sys_setns, compat_sys_process_vm_readv, compat_sys_process_vm_writev
>> /*340*/ .word sys_kern_features, sys_kcmp, sys_finit_module, sys_sched_setattr, sys_sched_getattr
>> .word sys32_renameat2, sys_seccomp, sys_getrandom, sys_memfd_create, sys_bpf
>> +/*350*/ .word sys_execveat
>
> Shouldn't this be compat_sys_execveat?
Yeah, that would make sense -- thanks for spotting.
Looking at this more closely, I also wonder if we need a pair of wrappers
analogous to sys(32|64)_execve -- they include a (pipeline-executed)
flushw instruction after the jmpl to [compat_]sys_execve, which I guess
might be needed. So I could add something like the following to
arch/sparc/kernel/syscalls.S:
sys64_execveat:
set sys_execveat, %g1
jmpl %g1, %g0
flushw
#ifdef CONFIG_COMPAT
sys32_execveat:
set compat_sys_execveat, %g1
jmpl %g1, %g0
flushw
#endif
However, I don't speak SPARC and can't run the code -- any thoughts
out there from someone who does & can?
Or maybe I should stop trying to be helpful with speculative patches, and
just leave wiring up the sparc stuff to the experts...
>>
>> #endif /* CONFIG_COMPAT */
>
> --
> Cheers,
> Stephen Rothwell [email protected]
From: David Drysdale <[email protected]>
Date: Thu, 20 Nov 2014 11:28:22 +0000
> On Wed, Nov 19, 2014 at 11:42 PM, Stephen Rothwell <[email protected]> wrote:
>> Hi David,
>>
>> On Wed, 19 Nov 2014 17:27:51 +0000 David Drysdale <[email protected]> wrote:
>>>
>>> diff --git a/arch/sparc/kernel/systbls_64.S b/arch/sparc/kernel/systbls_64.S
>>> index 580cde9370c9..15069cb35dac 100644
>>> --- a/arch/sparc/kernel/systbls_64.S
>>> +++ b/arch/sparc/kernel/systbls_64.S
>>> @@ -88,6 +88,7 @@ sys_call_table32:
>>> .word sys_syncfs, compat_sys_sendmmsg, sys_setns, compat_sys_process_vm_readv, compat_sys_process_vm_writev
>>> /*340*/ .word sys_kern_features, sys_kcmp, sys_finit_module, sys_sched_setattr, sys_sched_getattr
>>> .word sys32_renameat2, sys_seccomp, sys_getrandom, sys_memfd_create, sys_bpf
>>> +/*350*/ .word sys_execveat
>>
>> Shouldn't this be compat_sys_execveat?
>
> Yeah, that would make sense -- thanks for spotting.
>
> Looking at this more closely, I also wonder if we need a pair of wrappers
> analogous to sys(32|64)_execve -- they include a (pipeline-executed)
> flushw instruction after the jmpl to [compat_]sys_execve, which I guess
> might be needed. So I could add something like the following to
> arch/sparc/kernel/syscalls.S:
>
> sys64_execveat:
> set sys_execveat, %g1
> jmpl %g1, %g0
> flushw
> #ifdef CONFIG_COMPAT
> sys32_execveat:
> set compat_sys_execveat, %g1
> jmpl %g1, %g0
> flushw
> #endif
>
> However, I don't speak SPARC and can't run the code -- any thoughts
> out there from someone who does & can?
>
> Or maybe I should stop trying to be helpful with speculative patches, and
> just leave wiring up the sparc stuff to the experts...
You need wrappers for execve() like system calls yes, in order to flush all
of the user register windows to the stack before the kill the address space.
I think your code snippet above is fine, except that you should indent
the flushw by one space more because it is in the delay slot of a
control transfer instruction.
Thanks.