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| author | Richard Miller <miller.research@gmail.com> | 2016-03-26 19:35:21 +0000 |
|---|---|---|
| committer | Brad Fitzpatrick <bradfitz@golang.org> | 2016-03-29 00:03:14 +0000 |
| commit | 1f0bebcc7260480550ad114048a9428cea68e4f1 (patch) | |
| tree | bef4da1a688e02cfde094d423cd451c10cd42751 /src/syscall/exec_linux.go | |
| parent | 272df158ac431cc253b87a713735df70155ed456 (diff) | |
| download | go-1f0bebcc7260480550ad114048a9428cea68e4f1.tar.xz | |
syscall: fix accidental close of exec status pipe in StartProcess
In syscall.forkAndExecInChild, blocks of code labelled Pass 1
and Pass 2 permute the file descriptors (if necessary) which are
passed to the child process. If Pass 1 begins with fds = {0,2,1},
nextfd = 4 and pipe = 4, then the statement labelled "don't stomp
on pipe" is too late -- the pipe (which will be needed to pass
exec status back to the parent) will have been closed by the
preceding DUP call.
Moving the "don't stomp" test earlier ensures that the pipe is
protected.
Fixes #14979
Change-Id: I890c311527f6aa255be48b3277c1e84e2049ee22
Reviewed-on: https://go-review.googlesource.com/21184
Run-TryBot: David du Colombier <0intro@gmail.com>
Reviewed-by: David du Colombier <0intro@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Diffstat (limited to 'src/syscall/exec_linux.go')
| -rw-r--r-- | src/syscall/exec_linux.go | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/src/syscall/exec_linux.go b/src/syscall/exec_linux.go index c1fd53cc6e..e49bad75b2 100644 --- a/src/syscall/exec_linux.go +++ b/src/syscall/exec_linux.go @@ -255,6 +255,9 @@ func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr } for i = 0; i < len(fd); i++ { if fd[i] >= 0 && fd[i] < int(i) { + if nextfd == pipe { // don't stomp on pipe + nextfd++ + } _, _, err1 = RawSyscall(_SYS_dup, uintptr(fd[i]), uintptr(nextfd), 0) if err1 != 0 { goto childerror @@ -262,9 +265,6 @@ func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr RawSyscall(SYS_FCNTL, uintptr(nextfd), F_SETFD, FD_CLOEXEC) fd[i] = nextfd nextfd++ - if nextfd == pipe { // don't stomp on pipe - nextfd++ - } } } |