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Date: Thu, 6 Nov 2014 10:06:07 -0800
From: Kees Cook <keescook@...omium.org>
To: David Drysdale <drysdale@...gle.com>
Cc: "Eric W. Biederman" <ebiederm@...ssion.com>,
Andy Lutomirski <luto@...capital.net>,
Alexander Viro <viro@...iv.linux.org.uk>,
Meredydd Luff <meredydd@...atehouse.org>,
LKML <linux-kernel@...r.kernel.org>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>,
"H. Peter Anvin" <hpa@...or.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Arnd Bergmann <arnd@...db.de>, Rich Felker <dalias@...ifal.cx>,
Christoph Hellwig <hch@...radead.org>,
"x86@...nel.org" <x86@...nel.org>,
linux-arch <linux-arch@...r.kernel.org>,
Linux API <linux-api@...r.kernel.org>
Subject: Re: [PATCHv6 1/3] syscalls,x86: implement execveat() system call
On Thu, Nov 6, 2014 at 8:07 AM, David Drysdale <drysdale@...gle.com> wrote:
> 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).
>
> Only x86-64, i386 and x32 ABIs are supported in this patch.
>
> Based on patches by Meredydd Luff <meredydd@...atehouse.org>
This'll be quite nice for doing launches into a tight sandbox.
>
> Signed-off-by: David Drysdale <drysdale@...gle.com>
> ---
> 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 | 115 +++++++++++++++++++++++++++++++++-----
> fs/namei.c | 8 ++-
> include/linux/binfmts.h | 4 ++
> include/linux/compat.h | 3 +
> include/linux/fs.h | 1 +
> include/linux/namei.h | 1 +
> include/linux/sched.h | 4 ++
> include/linux/syscalls.h | 4 ++
> include/uapi/asm-generic/unistd.h | 4 +-
> kernel/sys_ni.c | 3 +
> lib/audit.c | 3 +
> 21 files changed, 188 insertions(+), 15 deletions(-)
>
> 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 4299eb05023c..2516c09743e0 100644
> --- a/arch/x86/ia32/ia32entry.S
> +++ b/arch/x86/ia32/ia32entry.S
> @@ -464,6 +464,7 @@ 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 2fac1343a90b..00c4526e6ffe 100644
> --- a/arch/x86/kernel/entry_64.S
> +++ b/arch/x86/kernel/entry_64.S
> @@ -665,6 +665,20 @@ 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.
> @@ -710,6 +724,20 @@ 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 028b78168d85..2633e3195455 100644
> --- a/arch/x86/syscalls/syscall_32.tbl
> +++ b/arch/x86/syscalls/syscall_32.tbl
> @@ -363,3 +363,4 @@
> 354 i386 seccomp sys_seccomp
> 355 i386 getrandom sys_getrandom
> 356 i386 memfd_create sys_memfd_create
> +357 i386 execveat sys_execveat stub32_execveat
> diff --git a/arch/x86/syscalls/syscall_64.tbl b/arch/x86/syscalls/syscall_64.tbl
> index 35dd922727b9..1af5badd159c 100644
> --- a/arch/x86/syscalls/syscall_64.tbl
> +++ b/arch/x86/syscalls/syscall_64.tbl
> @@ -327,6 +327,7 @@
> 318 common getrandom sys_getrandom
> 319 common memfd_create sys_memfd_create
> 320 common kexec_file_load sys_kexec_file_load
> +321 64 execveat stub_execveat
>
> #
> # x32-specific system call numbers start at 512 to avoid cache impact
> @@ -365,3 +366,4 @@
> 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)
> 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 b60500300dd7..e659f5562356 100644
> --- a/fs/binfmt_misc.c
> +++ b/fs/binfmt_misc.c
> @@ -127,6 +127,10 @@ 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 a2b42a98c743..800d232c17bb 100644
> --- a/fs/exec.c
> +++ b/fs/exec.c
> @@ -747,18 +747,26 @@ 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 |
> + LOOKUP_EMPTY_NOPATH);
> +
> + file = do_filp_open(fd, name, &open_exec_flags);
> if (IS_ERR(file))
> goto out;
>
> @@ -769,12 +777,13 @@ 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 +795,7 @@ 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);
>
> @@ -1422,10 +1431,12 @@ 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;
> @@ -1466,7 +1477,7 @@ 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;
> @@ -1474,7 +1485,30 @@ 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 {
> + /* "/dev/fd/2147483647/" + filename->name */
> + int maxlen = 19 + strlen(filename->name);
This should be 20 + strlen (to include the trailing NULL). However, I
think this whole bit of code could be replaced with kasprintf...
> +
> + pathbuf = kmalloc(maxlen, GFP_TEMPORARY);
> + if (!pathbuf) {
> + retval = -ENOMEM;
> + goto out_unmark;
> + }
> + if (filename->name[0] == '\0')
> + sprintf(pathbuf, "/dev/fd/%d", fd);
> + else
> + snprintf(pathbuf, maxlen,
> + "/dev/fd/%d/%s", fd, filename->name);
Maybe something like this? A bit messy, so maybe your original if/else
would be more readable.
} else {
pathbuf = kasprintf("/dev/fd/%d%s%s", fd,
filename->name[0] == '\0' ? "" : "/",
filename->name[0] == '\0' ? ""
: 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, current->files->fdt))
> + bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE;
> + bprm->filename = pathbuf;
> + }
> + bprm->interp = bprm->filename;
>
> retval = bprm_mm_init(bprm);
> if (retval)
> @@ -1532,6 +1566,7 @@ out_unmark:
>
> out_free:
> free_bprm(bprm);
> + kfree(pathbuf);
>
> out_files:
> if (displaced)
> @@ -1547,7 +1582,18 @@ 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
> @@ -1563,7 +1609,23 @@ 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
>
> @@ -1603,6 +1665,20 @@ 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,
> @@ -1610,4 +1686,17 @@ 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 a7b05bf82d31..757df6777ae5 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;
> @@ -1891,6 +1891,12 @@ static int path_init(int dfd, const char *name, unsigned int flags,
> fdput(f);
> return -ENOTDIR;
> }
> + } else if (flags & LOOKUP_EMPTY_NOPATH) {
> + /* When using the fd alone, disallow O_PATH files */
> + if (f.file->f_mode & FMODE_PATH) {
> + fdput(f);
> + return -EBADF;
> + }
> }
>
> nd->path = f.file->f_path;
> 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 94187721ad41..e9818574d738 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2060,6 +2060,7 @@ extern struct file *file_open_root(struct dentry *, struct vfsmount *,
> 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/namei.h b/include/linux/namei.h
> index 492de72560fa..eaa25cc72213 100644
> --- a/include/linux/namei.h
> +++ b/include/linux/namei.h
> @@ -55,6 +55,7 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
> #define LOOKUP_JUMPED 0x1000
> #define LOOKUP_ROOT 0x2000
> #define LOOKUP_EMPTY 0x4000
> +#define LOOKUP_EMPTY_NOPATH 0x8000
>
> extern int user_path_at(int, const char __user *, unsigned, struct path *);
> extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index b867a4dab38a..33e056da7d33 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -2430,6 +2430,10 @@ 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 0f86d85a9ce4..df5422294deb 100644
> --- a/include/linux/syscalls.h
> +++ b/include/linux/syscalls.h
> @@ -876,4 +876,8 @@ 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_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 11d11bc5c78f..feef07d29663 100644
> --- a/include/uapi/asm-generic/unistd.h
> +++ b/include/uapi/asm-generic/unistd.h
> @@ -705,9 +705,11 @@ __SYSCALL(__NR_seccomp, sys_seccomp)
> __SYSCALL(__NR_getrandom, sys_getrandom)
> #define __NR_memfd_create 279
> __SYSCALL(__NR_memfd_create, sys_memfd_create)
> +#define __NR_execveat 280
> +__SC_COMP(__NR_execveat, sys_execveat, compat_sys_execveat)
>
> #undef __NR_syscalls
> -#define __NR_syscalls 280
> +#define __NR_syscalls 281
>
> /*
> * All syscalls below here should go away really,
> diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
> index 391d4ddb6f4b..efb06058ad3e 100644
> --- a/kernel/sys_ni.c
> +++ b/kernel/sys_ni.c
> @@ -218,3 +218,6 @@ cond_syscall(sys_kcmp);
>
> /* operate on Secure Computing state */
> cond_syscall(sys_seccomp);
> +
> +/* 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
>
Thanks for working on this!
-Kees
--
Kees Cook
Chrome OS Security
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