diff options
| author | Michael Pratt <mpratt@google.com> | 2018-12-10 12:36:27 -0800 |
|---|---|---|
| committer | Shentubot <shentubot@google.com> | 2018-12-10 12:37:16 -0800 |
| commit | 99d595869332f817de8f570fae184658c513a43c (patch) | |
| tree | 0e1309f278df51d47a4059ab9c1ef5c3b37f14ca /pkg/sentry/syscalls | |
| parent | 25b8424d754bd659a0f976f82f7c8846dc2a194f (diff) | |
Validate FS_BASE in Task.Clone
arch_prctl already verified that the new FS_BASE was canonical, but
Task.Clone did not. Centralize these checks in the arch packages.
Failure to validate could cause an error in PTRACE_SET_REGS when we try
to switch to the app.
PiperOrigin-RevId: 224862398
Change-Id: Iefe63b3f9aa6c4810326b8936e501be3ec407f14
Diffstat (limited to 'pkg/sentry/syscalls')
| -rw-r--r-- | pkg/sentry/syscalls/linux/sys_tls.go | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/pkg/sentry/syscalls/linux/sys_tls.go b/pkg/sentry/syscalls/linux/sys_tls.go index 40e84825b..8ea78093b 100644 --- a/pkg/sentry/syscalls/linux/sys_tls.go +++ b/pkg/sentry/syscalls/linux/sys_tls.go @@ -22,7 +22,6 @@ import ( "gvisor.googlesource.com/gvisor/pkg/abi/linux" "gvisor.googlesource.com/gvisor/pkg/sentry/arch" "gvisor.googlesource.com/gvisor/pkg/sentry/kernel" - "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" ) // ArchPrctl implements linux syscall arch_prctl(2). @@ -31,19 +30,17 @@ func ArchPrctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys switch args[0].Int() { case linux.ARCH_GET_FS: addr := args[1].Pointer() - _, err := t.CopyOut(addr, &t.Arch().StateData().Regs.Fs_base) + fsbase := t.Arch().TLS() + _, err := t.CopyOut(addr, uint64(fsbase)) if err != nil { return 0, nil, err } case linux.ARCH_SET_FS: fsbase := args[1].Uint64() - if _, ok := t.MemoryManager().CheckIORange(usermem.Addr(fsbase), 0); !ok { + if !t.Arch().SetTLS(uintptr(fsbase)) { return 0, nil, syscall.EPERM } - regs := &t.Arch().StateData().Regs - regs.Fs = 0 - regs.Fs_base = fsbase case linux.ARCH_GET_GS, linux.ARCH_SET_GS: t.Kernel().EmitUnimplementedEvent(t) |