Index: content/common/sandbox_seccomp_bpf_linux.cc |
diff --git a/content/common/sandbox_seccomp_bpf_linux.cc b/content/common/sandbox_seccomp_bpf_linux.cc |
index cbea595dba9d203d0d73b60b60b84643c7f4a1f2..27a7ea918bac264d25d8357714e99d1a2fdbb5a9 100644 |
--- a/content/common/sandbox_seccomp_bpf_linux.cc |
+++ b/content/common/sandbox_seccomp_bpf_linux.cc |
@@ -197,55 +197,55 @@ bool IsAmbientFileSystemSyscall(int sysno) { |
// System calls that directly access the file system. They might aquire |
// a new file descriptor or otherwise perform an operation directly |
// via a path. |
-// For many, EPERM is a valid errno, but not for all of them. |
+// Both EPERM and ENOENT are valid errno unless otherwise noted in comment. |
bool IsFileSystemSyscall(int sysno) { |
switch (sysno) { |
- case __NR_access: |
- // case __NR_chmod: |
- // case __NR_chown: |
- // case __NR_creat: |
+ case __NR_access: // EPERM not a valid errno. |
+ case __NR_chmod: |
+ case __NR_chown: |
+ case __NR_creat: |
case __NR_execve: |
- // case __NR_faccessat: |
- // case __NR_fchmodat: |
- // case __NR_fchownat: // Should be called chownat ? |
- // case __NR_futimesat: // Should be called utimesat ? |
- // case __NR_getdents: |
- // case __NR_getdents64: |
- // case __NR_lchown: |
- // case __NR_link: |
- // case __NR_linkat: |
- // case __NR_lookup_dcookie: |
- case __NR_lstat: |
+ case __NR_faccessat: // EPERM not a valid errno. |
+ case __NR_fchmodat: |
+ case __NR_fchownat: // Should be called chownat ? |
+ case __NR_futimesat: // Should be called utimesat ? |
+ case __NR_lchown: |
+ case __NR_link: |
+ case __NR_linkat: |
+ case __NR_lookup_dcookie: // ENOENT not a valid errno. |
+ case __NR_lstat: // EPERM not a valid errno. |
case __NR_mkdir: |
case __NR_mkdirat: |
case __NR_mknod: |
case __NR_mknodat: |
- // case __NR_newfstatat: // Should be called statat ? |
+ case __NR_newfstatat: // EPERM not a valid errno. |
+ // Should be called statat ? |
case __NR_open: |
case __NR_openat: |
- case __NR_readlink: |
+ case __NR_readlink: // EPERM not a valid errno. |
case __NR_readlinkat: |
- // case __NR_rename: |
- // case __NR_renameat: |
- // case __NR_rmdir: |
- case __NR_stat: |
- // case __NR_statfs: |
- // case __NR_symlink: |
- // case __NR_symlinkat: |
- // case __NR_truncate: |
- // case __NR_unlink: |
- // case __NR_unlinkat: |
- // case __NR_uselib: |
- // case __NR_ustat: // Deprecated. |
- // case __NR_utime: |
- // case __NR_utimensat: // New. |
- // case __NR_utimes: |
+ case __NR_rename: |
+ case __NR_renameat: |
+ case __NR_rmdir: |
+ case __NR_stat: // EPERM not a valid errno. |
+ case __NR_statfs: // EPERM not a valid errno. |
+ case __NR_symlink: |
+ case __NR_symlinkat: |
+ case __NR_truncate: |
+ case __NR_unlink: |
+ case __NR_unlinkat: |
+ case __NR_uselib: // Neither EPERM, nor ENOENT are valid errno. |
+ case __NR_ustat: // Same as above. Deprecated. |
+ case __NR_utime: |
+ case __NR_utimensat: // New. |
+ case __NR_utimes: |
return true; |
default: |
return false; |
} |
} |
+// TODO(jln): these should be denied gracefully as well. |
bool IsAllowedFileSystemCapabilitySyscall(int sysno) { |
switch (sysno) { |
// case __NR_fadvise64: |
@@ -256,27 +256,38 @@ bool IsAllowedFileSystemCapabilitySyscall(int sysno) { |
// case __NR_fdatasync: |
// case __NR_sync_file_range: |
return true; |
+ default: |
+ return false; |
+ } |
+} |
+ |
+// EPERM is a good errno for any of these unless noted in comments. |
+bool IsDeniedFileSystemCapabilitySyscall(int sysno) { |
+ switch (sysno) { |
case __NR_fallocate: |
case __NR_fchmod: |
case __NR_fchown: |
case __NR_ftruncate: |
+ case __NR_getdents: // EPERM not a valid errno. |
+ case __NR_getdents64: // EPERM not a valid errno. |
+ return true; |
default: |
return false; |
} |
} |
-bool IsGetProcessIdSyscall(int sysno) { |
+bool IsGetSimpleId(int sysno) { |
switch (sysno) { |
// case __NR_capget: |
case __NR_getegid: |
case __NR_geteuid: |
case __NR_getgid: |
- // case __NR_getgroups: |
- // case __NR_getpid: |
- // case __NR_getppid: |
- // case __NR_getresgid: |
- // case __NR_getresuid: |
- // case __NR_getsid: |
+ case __NR_getgroups: |
+ case __NR_getpid: |
+ case __NR_getppid: |
+ case __NR_getresgid: |
+ case __NR_getresuid: |
+ case __NR_getsid: |
case __NR_gettid: |
case __NR_getuid: |
return true; |
@@ -340,9 +351,9 @@ bool IsOperationOnFd(int sysno) { |
switch (sysno) { |
case __NR_close: |
case __NR_dup: |
- // case __NR_dup2: |
- // case __NR_dup3: |
- case __NR_fcntl: |
+ case __NR_dup2: |
+ case __NR_dup3: |
+ case __NR_fcntl: // TODO(jln): we may want to restrict arguments. |
case __NR_shutdown: |
return true; |
default: |
@@ -359,6 +370,7 @@ bool IsKernelInteralApi(int sysno) { |
} |
} |
+// This should be thought through in conjunction with IsFutex(). |
bool IsAllowedProcessStartOrDeath(int sysno) { |
switch (sysno) { |
case __NR_clone: // TODO(jln): restrict flags. |
@@ -370,8 +382,8 @@ bool IsAllowedProcessStartOrDeath(int sysno) { |
// case __NR_set_tid_address: |
// case __NR_unshare: |
// case __NR_vfork: |
- // case __NR_wait4: |
- // case __NR_waitid: |
+ case __NR_wait4: |
+ case __NR_waitid: |
return true; |
case __NR_setns: // Privileged. |
default: |
@@ -379,6 +391,17 @@ bool IsAllowedProcessStartOrDeath(int sysno) { |
} |
} |
+bool IsFutex(int sysno) { |
+ switch (sysno) { |
+ case __NR_futex: |
+ // case __NR_get_robust_list: |
+ case __NR_set_robust_list: |
+ return true; |
+ default: |
+ return false; |
+ } |
+} |
+ |
bool IsAllowedEpoll(int sysno) { |
switch (sysno) { |
case __NR_epoll_create: |
@@ -423,30 +446,19 @@ bool IsNetworkSocketInformation(int sysno) { |
} |
} |
-bool IsFutex(int sysno) { |
- switch (sysno) { |
- case __NR_futex: |
- // case __NR_get_robust_list: |
- case __NR_set_robust_list: |
- return true; |
- default: |
- return false; |
- } |
-} |
- |
bool IsAllowedAddressSpaceAccess(int sysno) { |
switch (sysno) { |
case __NR_brk: |
case __NR_madvise: |
// case __NR_mincore: |
- // case __NR_mlock: |
+ case __NR_mlock: |
// case __NR_mlockall: |
- case __NR_mmap: |
+ case __NR_mmap: // TODO(jln): to restrict flags. |
// case __NR_modify_ldt: |
case __NR_mprotect: |
// case __NR_mremap: |
// case __NR_msync: |
- // case __NR_munlock: |
+ case __NR_munlock: |
// case __NR_munlockall: |
case __NR_munmap: |
// case __NR_readahead: |
@@ -460,28 +472,28 @@ bool IsAllowedAddressSpaceAccess(int sysno) { |
bool IsAllowedGeneralIo(int sysno) { |
switch (sysno) { |
case __NR_lseek: |
- // case __NR_poll: |
- // case __NR_ppoll: |
+ case __NR_poll: |
+ case __NR_ppoll: |
// case __NR_pread64: |
// case __NR_preadv: |
- // case __NR_pselect6: |
+ case __NR_pselect6: |
// case __NR_pwrite64: |
// case __NR_pwritev: |
case __NR_read: |
- // case __NR_readv: |
- // case __NR_recvfrom: // Could specify source. |
+ case __NR_readv: |
+ case __NR_recvfrom: // Could specify source. |
// case __NR_recvmmsg: // Could specify source. |
case __NR_recvmsg: // Could specify source. |
- // case __NR_select: |
+ case __NR_select: |
// case __NR_sendfile: |
// case __NR_sendmmsg: // Could specify destination. |
case __NR_sendmsg: // Could specify destination. |
- // case __NR_sendto: // Could specify destination. |
+ case __NR_sendto: // Could specify destination. |
// case __NR_splice: |
// case __NR_tee: |
// case __NR_vmsplice: |
case __NR_write: |
- // case __NR_writev: |
+ case __NR_writev: |
return true; |
default: |
case __NR_ioctl: // Can be very powerful. |
@@ -502,8 +514,8 @@ bool IsAllowedPrctl(int sysno) { |
bool IsAllowedBasicScheduler(int sysno) { |
switch (sysno) { |
case __NR_sched_yield: |
- // case __NR_pause: |
- // case __NR_nanosleep: |
+ case __NR_pause: |
+ case __NR_nanosleep: |
// case __NR_getpriority: |
return true; |
case __NR_setpriority: |
@@ -633,7 +645,7 @@ bool IsGlobalSystemStatus(int sysno) { |
bool IsEventFd(int sysno) { |
switch (sysno) { |
case __NR_eventfd: |
- // case __NR_eventfd2: |
+ case __NR_eventfd2: |
return true; |
default: |
return false; |
@@ -815,7 +827,7 @@ bool IsMiscSyscall(int sysno) { |
// End of the system call sets section. |
// x86_64 only because it references system calls that are multiplexed on IA32. |
-bool IsGpuAndFlashPolicyAllowed_x86_64(int sysno) { |
+bool IsBaselinePolicyAllowed_x86_64(int sysno) { |
if (IsAllowedAddressSpaceAccess(sysno) || |
IsAllowedBasicScheduler(sysno) || |
IsAllowedEpoll(sysno) || |
@@ -827,7 +839,7 @@ bool IsGpuAndFlashPolicyAllowed_x86_64(int sysno) { |
IsAllowedProcessStartOrDeath(sysno) || |
IsAllowedSignalHandling(sysno) || |
IsFutex(sysno) || |
- IsGetProcessIdSyscall(sysno) || |
+ IsGetSimpleId(sysno) || |
IsKernelInteralApi(sysno) || |
IsKillSyscall(sysno) || |
IsOperationOnFd(sysno)) { |
@@ -838,7 +850,7 @@ bool IsGpuAndFlashPolicyAllowed_x86_64(int sysno) { |
} |
// System calls that will trigger the crashing sigsys handler. |
-bool IsGpuAndFlashPolicyWatched_x86_64(int sysno) { |
+bool IsBaselinePolicyWatched_x86_64(int sysno) { |
if (IsAdminOperation(sysno) || |
IsAdvancedScheduler(sysno) || |
IsAdvancedTimer(sysno) || |
@@ -870,22 +882,36 @@ bool IsGpuAndFlashPolicyWatched_x86_64(int sysno) { |
} |
} |
+playground2::Sandbox::ErrorCode BaselinePolicy_x86_64(int sysno) { |
+ if (IsBaselinePolicyAllowed_x86_64(sysno)) { |
+ return playground2::Sandbox::SB_ALLOWED; |
+ } |
+ // TODO(jln): some system calls in those sets are not supposed to |
+ // return ENOENT. Return the appropriate error. |
+ if (IsFileSystemSyscall(sysno) || IsAmbientFileSystemSyscall(sysno)) { |
+ return ENOENT; |
+ } |
+ |
+ if (IsDeniedFileSystemCapabilitySyscall(sysno)) { |
+ return EPERM; |
+ } |
+ |
+ if (IsBaselinePolicyWatched_x86_64(sysno)) { |
+ // Previously unseen syscalls. TODO(jln): some of these should |
+ // be denied gracefully right away. |
+ return playground2::Sandbox::ErrorCode(CrashSIGSYS_Handler, NULL); |
+ } |
+ // In any other case crash the program with our SIGSYS handler |
+ return playground2::Sandbox::ErrorCode(CrashSIGSYS_Handler, NULL); |
+} |
+ |
// x86_64 only because it references system calls that are multiplexed on IA32. |
playground2::Sandbox::ErrorCode GpuProcessPolicy_x86_64(int sysno) { |
switch(sysno) { |
- case __NR_getpid: // Nvidia binary driver. |
- case __NR_getppid: // ATI binary driver. |
case __NR_ioctl: |
- case __NR_mlock: |
- case __NR_munlock: |
- case __NR_poll: |
- case __NR_recvfrom: |
- case __NR_writev: |
return playground2::Sandbox::SB_ALLOWED; |
case __NR_socket: |
return EACCES; // Nvidia binary driver. |
- case __NR_fchmod: |
- return EPERM; // ATI binary driver. |
case __NR_open: |
// Accelerated video decode is enabled by default only on Chrome OS. |
if (IsAcceleratedVideoDecodeEnabled()) { |
@@ -902,22 +928,11 @@ playground2::Sandbox::ErrorCode GpuProcessPolicy_x86_64(int sysno) { |
return playground2::Sandbox::ErrorCode(GpuOpenSIGSYS_Handler, NULL); |
} |
default: |
- if (IsGpuAndFlashPolicyAllowed_x86_64(sysno) || IsEventFd(sysno)) { |
+ if (IsEventFd(sysno)) |
return playground2::Sandbox::SB_ALLOWED; |
- } |
- // Generally, filename-based syscalls will fail with ENOENT to behave |
- // similarly to a possible future setuid sandbox. |
- if (IsFileSystemSyscall(sysno) || IsAmbientFileSystemSyscall(sysno)) { |
- return ENOENT; |
- } |
- if (IsGpuAndFlashPolicyWatched_x86_64(sysno)) { |
- // Previously unseen syscalls. TODO(jln): some of these should |
- // be denied gracefully right away. |
- return playground2::Sandbox::ErrorCode(CrashSIGSYS_Handler, NULL); |
- } |
- // In any other case crash the program with our SIGSYS handler |
- return playground2::Sandbox::ErrorCode(CrashSIGSYS_Handler, NULL); |
+ // Default on the baseline policy. |
+ return BaselinePolicy_x86_64(sysno); |
} |
} |
@@ -926,29 +941,20 @@ playground2::Sandbox::ErrorCode FlashProcessPolicy_x86_64(int sysno) { |
switch (sysno) { |
case __NR_sched_getaffinity: |
case __NR_sched_setscheduler: |
- // These are under investigation, and hopefully not here for the long term. |
case __NR_times: |
- case __NR_wait4: |
return playground2::Sandbox::SB_ALLOWED; |
case __NR_ioctl: |
return ENOTTY; // Flash Access. |
case __NR_socket: |
return EACCES; |
default: |
- if (IsGpuAndFlashPolicyAllowed_x86_64(sysno) || |
- IsSystemVSharedMemory(sysno)) { |
+ // These are under investigation, and hopefully not here for the long |
+ // term. |
+ if (IsSystemVSharedMemory(sysno)) |
return playground2::Sandbox::SB_ALLOWED; |
- } |
- if (IsFileSystemSyscall(sysno) || IsAmbientFileSystemSyscall(sysno)) { |
- return ENOENT; |
- } |
- if (IsGpuAndFlashPolicyWatched_x86_64(sysno)) { |
- // Previously unseen syscalls. TODO(jln): some of these should |
- // be denied gracefully right away. |
- return playground2::Sandbox::ErrorCode(CrashSIGSYS_Handler, NULL); |
- } |
- // In any other case crash the program with our SIGSYS handler. |
- return playground2::Sandbox::ErrorCode(CrashSIGSYS_Handler, NULL); |
+ |
+ // Default on the baseline policy. |
+ return BaselinePolicy_x86_64(sysno); |
} |
} |
#endif |