From aa9b48cd1837644a1555fd7a370800924cef627a Mon Sep 17 00:00:00 2001 From: Derek Parker Date: Wed, 25 Nov 2020 16:31:57 +0000 Subject: [release-branch.go1.15] cmd/link/internal/ld/pe: fix segfault adding resource section The resource symbol may have been copied to the mmap'd output buffer. If so, certain conditions can cause that mmap'd output buffer to be munmap'd before we get a chance to use it. To avoid any issues we copy the data to the heap when the resource symbol exists. Fixes #42384 Change-Id: I32ef5420802d7313a3d965b8badfbcfb9f0fba4a GitHub-Last-Rev: 7b0f43011d06083ee3e871e48a87847636f738f9 GitHub-Pull-Request: golang/go#42427 Reviewed-on: https://go-review.googlesource.com/c/go/+/268018 Run-TryBot: Carlos Amedee TryBot-Result: Go Bot Reviewed-by: Russ Cox Reviewed-by: Cherry Zhang Reviewed-by: Than McIntosh Trust: Carlos Amedee --- src/cmd/link/internal/ld/pe.go | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/cmd/link/internal/ld/pe.go b/src/cmd/link/internal/ld/pe.go index c9cb25dbe5..5d68ca7d9c 100644 --- a/src/cmd/link/internal/ld/pe.go +++ b/src/cmd/link/internal/ld/pe.go @@ -1515,6 +1515,18 @@ func Asmbpe(ctxt *Link) { case sys.AMD64, sys.I386, sys.ARM: } + if rsrcsym != 0 { + // The resource symbol may have been copied to the mmap'd + // output buffer. If so, certain conditions can cause that + // mmap'd output buffer to be munmap'd before we get a chance + // to use it. To avoid any issues we copy the data to the heap + // when the resource symbol exists. + rsrc := ctxt.loader.Syms[rsrcsym] + data := make([]byte, len(rsrc.P)) + copy(data, rsrc.P) + rsrc.P = data + } + t := pefile.addSection(".text", int(Segtext.Length), int(Segtext.Length)) t.characteristics = IMAGE_SCN_CNT_CODE | IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_EXECUTE | IMAGE_SCN_MEM_READ if ctxt.LinkMode == LinkExternal { -- cgit v1.2.3-54-g00ecf