diff options
| author | Brian Geffon <bgeffon@google.com> | 2018-12-04 14:33:34 -0800 |
|---|---|---|
| committer | Shentubot <shentubot@google.com> | 2018-12-04 14:34:19 -0800 |
| commit | 2cab0e82ad8c1e38392b8c35aaa65d1121a9e2b2 (patch) | |
| tree | ee9988121f909ffefdbd19355ae28615740491d9 | |
| parent | 82719be42e636f86780d21b01e10ecb2c9a25e53 (diff) | |
Linkat(2) should sanity check flags.
PiperOrigin-RevId: 224047765
Change-Id: I6f3c75b33c32bf8f8910ea3fab35406d7d672d87
| -rw-r--r-- | pkg/sentry/syscalls/linux/sys_file.go | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/pkg/sentry/syscalls/linux/sys_file.go b/pkg/sentry/syscalls/linux/sys_file.go index 37c90f6fd..8673bca0d 100644 --- a/pkg/sentry/syscalls/linux/sys_file.go +++ b/pkg/sentry/syscalls/linux/sys_file.go @@ -1251,6 +1251,12 @@ func Linkat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal // AT_SYMLINK_FOLLOW can be specified in flags to cause oldpath to be // dereferenced if it is a symbolic link. flags := args[4].Int() + + // Sanity check flags. + if flags&^(linux.AT_SYMLINK_FOLLOW|linux.AT_EMPTY_PATH) != 0 { + return 0, nil, syserror.EINVAL + } + resolve := flags&linux.AT_SYMLINK_FOLLOW == linux.AT_SYMLINK_FOLLOW allowEmpty := flags&linux.AT_EMPTY_PATH == linux.AT_EMPTY_PATH |