This change spins up a new goroutine, locks it to a thread, then
unshares CLONE_FS which allows us to `Chdir` from inside the thread
without affecting the rest of the program.
The thread is no longer usable after unshare so it leaves the thread
locked to prevent go from returning the thread to the thread pool.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Go 1.15.7 contained a security fix for CVE-2021-3115, which allowed arbitrary
code to be executed at build time when using cgo on Windows. This issue also
affects Unix users who have “.” listed explicitly in their PATH and are running
“go get” outside of a module or with module mode disabled.
This issue is not limited to the go command itself, and can also affect binaries
that use `os.Command`, `os.LookPath`, etc.
From the related blogpost (ttps://blog.golang.org/path-security):
> Are your own programs affected?
>
> If you use exec.LookPath or exec.Command in your own programs, you only need to
> be concerned if you (or your users) run your program in a directory with untrusted
> contents. If so, then a subprocess could be started using an executable from dot
> instead of from a system directory. (Again, using an executable from dot happens
> always on Windows and only with uncommon PATH settings on Unix.)
>
> If you are concerned, then we’ve published the more restricted variant of os/exec
> as golang.org/x/sys/execabs. You can use it in your program by simply replacing
This patch replaces all uses of `os/exec` with `golang.org/x/sys/execabs`. While
some uses of `os/exec` should not be problematic (e.g. part of tests), it is
probably good to be consistent, in case code gets moved around.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
It's the only location this is used, so might as well move it
into that package. I could not find external users of this utility,
so not adding an alias / deprecation.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
setupLoop()'s Autoclear (LO_FLAGS_AUTOCLEAR) will destruct the
loopback device when all associated file descriptors are closed.
However this behavior didn't work before since setupLoop() was
returning a file name. The looppack device was destructed at
the end of the function when LoopParams had Autoclear = true.
Fixes#4969.
Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>
If a mount has specified `loop` option, we need to handle it on our
own instead of passing it to the kernel. In such case, create a
loopback device, attach the mount source to it, and mount the loopback
device rather than the mount source.
Signed-off-by: Peng Tao <bergwolf@hyper.sh>
`exec.CombinedOutput()` intermittently returns `ECHILD` due to our
signal handling.
`wait(2)`: https://man7.org/linux/man-pages/man2/wait.2.html
> ECHILD (for waitpid() or waitid()) The process specified by pid
> (waitpid()) or idtype and id (waitid()) does not exist or is
> not a child of the calling process. (This can happen for
> one's own child if the action for SIGCHLD is set to SIG_IGN.
> See also the Linux Notes section about threads.)
Fix#4387
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
When m.Type starts with either `fuse.` or `fuse3`, the
mount helper binary `mount.fuse` or `mount.fuse3` is executed.
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
* Rootfs dir is created during container creation not during bundle
creation
* Add support for v2
* UnmountAll is a no-op when the path to unmount (i.e. the rootfs dir)
does not exist or is invalid
Co-authored-by: Danail Branekov <danailster@gmail.com>
Signed-off-by: Georgi Sabev <georgethebeatle@gmail.com>
Auto-detect longest common dir in lowerdir option and compact it if the
option size is hitting one page size. If does, Use chdir + CLONE to do
mount thing to avoid hitting one page argument buffer in linux kernel
mount.
Signed-off-by: Wei Fu <fhfuwei@163.com>
This moves both the Mount type and mountinfo into a single mount
package.
This also opens up the root of the repo to hold the containerd client
implementation.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
