From 65633fee16f7a3d63c1d6918a80ac802a8f2d529 Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Wed, 8 Dec 2021 18:06:41 -0500 Subject: [PATCH] [release-branch.go1.17] syscall: avoid writing to p when Pipe(p) fails Generally speaking Go functions make no guarantees about what has happened to result parameters on error, and Pipe is no exception: callers should avoid looking at p if Pipe returns an error. However, we had a bug in which ForkExec was using the content of p after a failed Pipe, and others may too. As a robustness fix, make Pipe avoid writing to p on failure. Updates #50057 Change-Id: Ie8955025dbd20702fabadc9bbe1d1a5ac0f36305 Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/1291271 Reviewed-by: Ian Lance Taylor Reviewed-on: https://go-review.googlesource.com/c/go/+/370535 Trust: Filippo Valsorda Run-TryBot: Filippo Valsorda Reviewed-by: Alex Rakoczy --- src/syscall/syscall_aix.go | 6 ++++-- src/syscall/syscall_darwin.go | 6 ++++-- src/syscall/syscall_dragonfly.go | 12 +++++++++--- src/syscall/syscall_freebsd.go | 6 ++++-- src/syscall/syscall_linux_386.go | 12 ++++++++---- src/syscall/syscall_linux_amd64.go | 12 ++++++++---- src/syscall/syscall_linux_arm.go | 12 ++++++++---- src/syscall/syscall_linux_arm64.go | 12 ++++++++---- src/syscall/syscall_linux_mips64x.go | 12 ++++++++---- src/syscall/syscall_linux_mipsx.go | 13 +++++++++---- src/syscall/syscall_linux_ppc64x.go | 12 ++++++++---- src/syscall/syscall_linux_riscv64.go | 12 ++++++++---- src/syscall/syscall_linux_s390x.go | 12 ++++++++---- src/syscall/syscall_netbsd.go | 6 ++++-- src/syscall/syscall_openbsd.go | 6 ++++-- src/syscall/syscall_plan9.go | 6 ++++-- src/syscall/syscall_solaris.go | 4 +++- 17 files changed, 109 insertions(+), 52 deletions(-) diff --git a/src/syscall/syscall_aix.go b/src/syscall/syscall_aix.go index 9c6afba442..db289fd39c 100644 --- a/src/syscall/syscall_aix.go +++ b/src/syscall/syscall_aix.go @@ -64,8 +64,10 @@ func Pipe(p []int) (err error) { } var pp [2]_C_int err = pipe(&pp) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } diff --git a/src/syscall/syscall_darwin.go b/src/syscall/syscall_darwin.go index a4fe4f1962..ce69464f5f 100644 --- a/src/syscall/syscall_darwin.go +++ b/src/syscall/syscall_darwin.go @@ -96,8 +96,10 @@ func Pipe(p []int) (err error) { } var q [2]int32 err = pipe(&q) - p[0] = int(q[0]) - p[1] = int(q[1]) + if err == nil { + p[0] = int(q[0]) + p[1] = int(q[1]) + } return } diff --git a/src/syscall/syscall_dragonfly.go b/src/syscall/syscall_dragonfly.go index b01a4ada67..5ff7f99d52 100644 --- a/src/syscall/syscall_dragonfly.go +++ b/src/syscall/syscall_dragonfly.go @@ -96,8 +96,11 @@ func Pipe(p []int) (err error) { if len(p) != 2 { return EINVAL } - p[0], p[1], err = pipe() - return + r, w, err := pipe() + if err == nil { + p[0], p[1] = r, w + } + return err } //sysnb pipe2(p *[2]_C_int, flags int) (r int, w int, err error) @@ -109,7 +112,10 @@ func Pipe2(p []int, flags int) (err error) { var pp [2]_C_int // pipe2 on dragonfly takes an fds array as an argument, but still // returns the file descriptors. - p[0], p[1], err = pipe2(&pp, flags) + r, w, err := pipe2(&pp, flags) + if err == nil { + p[0], p[1] = r, w + } return err } diff --git a/src/syscall/syscall_freebsd.go b/src/syscall/syscall_freebsd.go index 7c7b89aab9..ad904d6981 100644 --- a/src/syscall/syscall_freebsd.go +++ b/src/syscall/syscall_freebsd.go @@ -105,8 +105,10 @@ func Pipe2(p []int, flags int) error { } var pp [2]_C_int err := pipe2(&pp, flags) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return err } diff --git a/src/syscall/syscall_linux_386.go b/src/syscall/syscall_linux_386.go index 0db037470d..26bdb9b78b 100644 --- a/src/syscall/syscall_linux_386.go +++ b/src/syscall/syscall_linux_386.go @@ -30,8 +30,10 @@ func Pipe(p []int) (err error) { } var pp [2]_C_int err = pipe(&pp) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } @@ -43,8 +45,10 @@ func Pipe2(p []int, flags int) (err error) { } var pp [2]_C_int err = pipe2(&pp, flags) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } diff --git a/src/syscall/syscall_linux_amd64.go b/src/syscall/syscall_linux_amd64.go index 5df3f796d1..896117adc8 100644 --- a/src/syscall/syscall_linux_amd64.go +++ b/src/syscall/syscall_linux_amd64.go @@ -118,8 +118,10 @@ func Pipe(p []int) (err error) { } var pp [2]_C_int err = pipe(&pp) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } @@ -131,8 +133,10 @@ func Pipe2(p []int, flags int) (err error) { } var pp [2]_C_int err = pipe2(&pp, flags) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } diff --git a/src/syscall/syscall_linux_arm.go b/src/syscall/syscall_linux_arm.go index e887cf788f..79c201a20f 100644 --- a/src/syscall/syscall_linux_arm.go +++ b/src/syscall/syscall_linux_arm.go @@ -34,8 +34,10 @@ func Pipe(p []int) (err error) { if err == ENOSYS { err = pipe(&pp) } - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } @@ -47,8 +49,10 @@ func Pipe2(p []int, flags int) (err error) { } var pp [2]_C_int err = pipe2(&pp, flags) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } diff --git a/src/syscall/syscall_linux_arm64.go b/src/syscall/syscall_linux_arm64.go index f575c84c93..bfa7be96aa 100644 --- a/src/syscall/syscall_linux_arm64.go +++ b/src/syscall/syscall_linux_arm64.go @@ -152,8 +152,10 @@ func Pipe(p []int) (err error) { } var pp [2]_C_int err = pipe2(&pp, 0) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } @@ -165,8 +167,10 @@ func Pipe2(p []int, flags int) (err error) { } var pp [2]_C_int err = pipe2(&pp, flags) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } diff --git a/src/syscall/syscall_linux_mips64x.go b/src/syscall/syscall_linux_mips64x.go index 5feb03e915..43f94111cd 100644 --- a/src/syscall/syscall_linux_mips64x.go +++ b/src/syscall/syscall_linux_mips64x.go @@ -109,8 +109,10 @@ func Pipe(p []int) (err error) { } var pp [2]_C_int err = pipe2(&pp, 0) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } @@ -122,8 +124,10 @@ func Pipe2(p []int, flags int) (err error) { } var pp [2]_C_int err = pipe2(&pp, flags) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } diff --git a/src/syscall/syscall_linux_mipsx.go b/src/syscall/syscall_linux_mipsx.go index 39104d71d8..1ab452e123 100644 --- a/src/syscall/syscall_linux_mipsx.go +++ b/src/syscall/syscall_linux_mipsx.go @@ -120,8 +120,10 @@ func Pipe2(p []int, flags int) (err error) { } var pp [2]_C_int err = pipe2(&pp, flags) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } @@ -131,8 +133,11 @@ func Pipe(p []int) (err error) { if len(p) != 2 { return EINVAL } - p[0], p[1], err = pipe() - return + r, w, err := pipe() + if err == nil { + p[0], p[1] = r, w + } + return err } //sys mmap2(addr uintptr, length uintptr, prot int, flags int, fd int, pageOffset uintptr) (xaddr uintptr, err error) diff --git a/src/syscall/syscall_linux_ppc64x.go b/src/syscall/syscall_linux_ppc64x.go index 495ae29757..8a69eb57b0 100644 --- a/src/syscall/syscall_linux_ppc64x.go +++ b/src/syscall/syscall_linux_ppc64x.go @@ -88,8 +88,10 @@ func Pipe(p []int) (err error) { } var pp [2]_C_int err = pipe2(&pp, 0) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } @@ -101,8 +103,10 @@ func Pipe2(p []int, flags int) (err error) { } var pp [2]_C_int err = pipe2(&pp, flags) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } diff --git a/src/syscall/syscall_linux_riscv64.go b/src/syscall/syscall_linux_riscv64.go index 2a0fe64d25..dd48f7c8db 100644 --- a/src/syscall/syscall_linux_riscv64.go +++ b/src/syscall/syscall_linux_riscv64.go @@ -155,8 +155,10 @@ func Pipe(p []int) (err error) { } var pp [2]_C_int err = pipe2(&pp, 0) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } @@ -168,8 +170,10 @@ func Pipe2(p []int, flags int) (err error) { } var pp [2]_C_int err = pipe2(&pp, flags) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } diff --git a/src/syscall/syscall_linux_s390x.go b/src/syscall/syscall_linux_s390x.go index 0f6f6277bb..08e66136b8 100644 --- a/src/syscall/syscall_linux_s390x.go +++ b/src/syscall/syscall_linux_s390x.go @@ -80,8 +80,10 @@ func Pipe(p []int) (err error) { } var pp [2]_C_int err = pipe2(&pp, 0) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } @@ -93,8 +95,10 @@ func Pipe2(p []int, flags int) (err error) { } var pp [2]_C_int err = pipe2(&pp, flags) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } diff --git a/src/syscall/syscall_netbsd.go b/src/syscall/syscall_netbsd.go index fc13b706b5..0754bad5ac 100644 --- a/src/syscall/syscall_netbsd.go +++ b/src/syscall/syscall_netbsd.go @@ -112,8 +112,10 @@ func Pipe2(p []int, flags int) error { } var pp [2]_C_int err := pipe2(&pp, flags) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return err } diff --git a/src/syscall/syscall_openbsd.go b/src/syscall/syscall_openbsd.go index 5a5ba5a51b..18eafe3521 100644 --- a/src/syscall/syscall_openbsd.go +++ b/src/syscall/syscall_openbsd.go @@ -72,8 +72,10 @@ func Pipe2(p []int, flags int) error { } var pp [2]_C_int err := pipe2(&pp, flags) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return err } diff --git a/src/syscall/syscall_plan9.go b/src/syscall/syscall_plan9.go index d16cad45d8..6a8ab97dc6 100644 --- a/src/syscall/syscall_plan9.go +++ b/src/syscall/syscall_plan9.go @@ -198,8 +198,10 @@ func Pipe(p []int) (err error) { } var pp [2]int32 err = pipe(&pp) - p[0] = int(pp[0]) - p[1] = int(pp[1]) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } return } diff --git a/src/syscall/syscall_solaris.go b/src/syscall/syscall_solaris.go index daa4b88a71..7640aac25b 100644 --- a/src/syscall/syscall_solaris.go +++ b/src/syscall/syscall_solaris.go @@ -55,7 +55,9 @@ func Pipe(p []int) (err error) { if e1 != 0 { err = Errno(e1) } - p[0], p[1] = int(r0), int(w0) + if err == nil { + p[0], p[1] = int(r0), int(w0) + } return } -- 2.48.1