mirror/runc
1
0
Fork 0
mirror of https://github.com/opencontainers/runc.git synced 2026-07-11 06:03:57 +08:00
Code Issues Packages Projects Releases Wiki Activity

Merge pull request #4392 from cyphar/1.1-remove-bindfd

Browse Source 
[1.1] nsenter: cloned_binary: remove bindfd logic entirely
This commit is contained in:
Kir Kolyshkin
2024-09-03 10:20:32 -07:00
committed by GitHub
parent 2655e7c5a8 614ce12f0e
commit bd671b6a13
1 changed files with 0 additions and 67 deletions
Download Patch File Download Diff File Expand all files Collapse all files
libcontainer/nsenter/cloned_binary.c
-67
View File
@@ -396,61 +396,6 @@ static int seal_execfd(int *fd, int fdtype)
return -1;
}
static int try_bindfd(void)
{
int fd, ret = -1;
char template[PATH_MAX] = { 0 };
char *prefix = getenv("_LIBCONTAINER_STATEDIR");
if (!prefix || *prefix != '/')
prefix = "/tmp";
if (snprintf(template, sizeof(template), "%s/runc.XXXXXX", prefix) < 0)
return ret;
/*
* We need somewhere to mount it, mounting anything over /proc/self is a
* BAD idea on the host -- even if we do it temporarily.
*/
fd = mkstemp(template);
if (fd < 0)
return ret;
close(fd);
/*
* For obvious reasons this won't work in rootless mode because we haven't
* created a userns+mntns -- but getting that to work will be a bit
* complicated and it's only worth doing if someone actually needs it.
*/
ret = -EPERM;
if (mount("/proc/self/exe", template, "", MS_BIND, "") < 0)
goto out;
if (mount("", template, "", MS_REMOUNT | MS_BIND | MS_RDONLY, "") < 0)
goto out_umount;
/* Get read-only handle that we're sure can't be made read-write. */
ret = open(template, O_PATH | O_CLOEXEC);
out_umount:
/*
* Make sure the MNT_DETACH works, otherwise we could get remounted
* read-write and that would be quite bad (the fd would be made read-write
* too, invalidating the protection).
*/
if (umount2(template, MNT_DETACH) < 0) {
if (ret >= 0)
close(ret);
ret = -ENOTRECOVERABLE;
}
out:
/*
* We don't care about unlink errors, the worst that happens is that
* there's an empty file left around in STATEDIR.
*/
unlink(template);
return ret;
}
static ssize_t fd_to_fd(int outfd, int infd)
{
ssize_t total = 0;
@@ -485,18 +430,6 @@ static int clone_binary(void)
size_t sent = 0;
int fdtype = EFD_NONE;
/*
* Before we resort to copying, let's try creating an ro-binfd in one shot
* by getting a handle for a read-only bind-mount of the execfd.
*/
execfd = try_bindfd();
if (execfd >= 0)
return execfd;
/*
* Dammit, that didn't work -- time to copy the binary to a safe place we
* can seal the contents.
*/
execfd = make_execfd(&fdtype);
if (execfd < 0 || fdtype == EFD_NONE)
return -ENOTRECOVERABLE;