Files
runc/libcontainer/eaccess_go119.go
T
Kir Kolyshkin 840b95394b Fix runc run "permission denied" when rootless
Since commit 957d97bcf4 was made to fix issue [7],
a few things happened:

- a similar functionality appeared in go 1.20 [1], so the issue
  mentioned in the comment (being removed) is no longer true;
- a bug in runc was found [2], which also affects go [3];
- the bug was fixed in go 1.21 [4] and 1.20.2 [5];
- a similar fix was made to x/sys/unix.Faccessat [6].

The essense of [2] is, even if a (non-root) user that the container is
run as does not have execute permission bit set for the executable, it
should still work in case runc has the CAP_DAC_OVERRIDE capability set.

To fix this [2] without reintroducing the older bug [7]:
- drop own Eaccess implementation;
- use the one from x/sys/unix for Go 1.19 (depends on [6]);
- do not use anything when Go 1.20+ is used.

NOTE it is virtually impossible to fix the bug [2] when Go 1.20 or Go
1.20.1 is used because of [3].

A test case is added by a separate commit.

Fixes: #3715.

[1] https://go-review.googlesource.com/c/go/+/414824
[2] https://github.com/opencontainers/runc/issues/3715
[3] https://go.dev/issue/58552
[4] https://go-review.googlesource.com/c/go/+/468735
[5] https://go-review.googlesource.com/c/go/+/469956
[6] https://go-review.googlesource.com/c/sys/+/468877
[7] https://github.com/opencontainers/runc/issues/3520

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
(cherry picked from commit 8491d33482)
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
2023-04-06 18:07:03 -07:00

18 lines
547 B
Go

//go:build !go1.20
// +build !go1.20
package libcontainer
import "golang.org/x/sys/unix"
func eaccess(path string) error {
// This check is similar to access(2) with X_OK except for
// setuid/setgid binaries where it checks against the effective
// (rather than real) uid and gid. It is not needed in go 1.20
// and beyond and will be removed later.
// Relies on code added in https://go-review.googlesource.com/c/sys/+/468877
// and older CLs linked from there.
return unix.Faccessat(unix.AT_FDCWD, path, unix.X_OK, unix.AT_EACCESS)
}