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| author | Michael Pratt <mpratt@google.com> | 2018-10-17 11:51:43 -0700 |
|---|---|---|
| committer | Shentubot <shentubot@google.com> | 2018-10-17 11:53:04 -0700 |
| commit | 578fe5a50dcf8e104b6bce3802987b0f8c069ade (patch) | |
| tree | 417958193942e67f24665434d6cd493af6451b9b | |
| parent | 6cba410df0ea2eabb87bad5074a8a79ed89312b8 (diff) | |
Fix PTRACE_GETREGSET write size
The existing logic is backwards and writes iov_len == 0 for a full write.
PiperOrigin-RevId: 217560377
Change-Id: I5a39c31bf0ba9063a8495993bfef58dc8ab7c5fa
| -rw-r--r-- | pkg/sentry/kernel/ptrace.go | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/pkg/sentry/kernel/ptrace.go b/pkg/sentry/kernel/ptrace.go index e21a25ae6..9fe28f435 100644 --- a/pkg/sentry/kernel/ptrace.go +++ b/pkg/sentry/kernel/ptrace.go @@ -921,7 +921,13 @@ func (t *Task) Ptrace(req int64, pid ThreadID, addr, data usermem.Addr) error { if err != nil { return err } - ar.End -= usermem.Addr(n) + + // Update iovecs to represent the range of the written register set. + end, ok := ar.Start.AddLength(uint64(n)) + if !ok { + panic(fmt.Sprintf("%#x + %#x overflows. Invalid reg size > %#x", ar.Start, n, ar.Length())) + } + ar.End = end return t.CopyOutIovecs(data, usermem.AddrRangeSeqOf(ar)) case linux.PTRACE_SETREGS: |