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>
Remove build tags which are already implied by the name of the file.
Ensures build tags are used consistently
Signed-off-by: Derek McGowan <derek@mcg.dev>
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>
Trying to reduce duplicated effort in maintaining a mountinfo
parser, this patch replaces the local implementation with the
implementation in github.com/moby/sys, which is actively maintained
and contains various optimizations.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
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>
The Err() method should be called after the Scan() loop, not inside it.
Found by: git grep -A3 -F '.Scan()'
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
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>
`/proc/self/mountinfo` uses `\040` for spaces, however, `parseInfoFile()`
did not decode those spaces in paths, therefore attempting to use `\040`
as a literal part of the path.
This patch un-quotes the `root` and `mount point` fields to fix
situations where paths contain spaces.
Note that the `mount source` field is not modified, given that
this field is documented (man `PROC(5)`) as:
filesystem-specific information or "none"
Which I interpreted as "the format in this field is undefined".
Reported-by: Daniil Yaroslavtsev <daniilyar@users.noreply.github.com>
Reported-by: Nathan Ringo <remexre@gmail.com>
Based-on-patch-by: Diego Becciolini <itizir@users.noreply.github.com>
Based-on-patch-by: Sergei Utinski <sergei-utinski@users.noreply.github.com>
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Implements the Windows lcow differ/snapshotter responsible for managing
the creation and lifetime of lcow containers on Windows.
Signed-off-by: Justin Terry (VM) <juterry@microsoft.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>
The mountinfo parser implemented via `fmt.Sscanf()` is slower than the one
using `strings.Split()` and `strconv.Atoi()`. This rewrite helps to speed it
up to a factor of 8x, here is a result from `go bench`:
> BenchmarkParsingScanf-4 300 22294112 ns/op
> BenchmarkParsingSplit-4 3000 2780703 ns/op
I tried other approaches, such as using `fmt.Sscanf()` for the first
three (integer) fields and `strings.Split()` for the rest, but it slows
things down considerably:
> BenchmarkParsingMixed-4 1000 8827058 ns/op
Note the old code uses `fmt.Sscanf` first, then a linear search for the
'-' field, then a split for the last 3 fields. The new code relies
on a single split.
One other thing is, the new code is more future proof as it skips
extra optional fields before the separator (currently there are none).
I have also added more comments to aid in future development.
Finally, the test data is fixed to not have white space before
the first field.
Based on a similar change in Moby,
https://github.com/moby/moby/pull/36091
[v2: remove no-op break statement to silence staticcheck]
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This allows non-privileged users to use containerd. This is part of a
larger track of work integrating containerd into Cloudfoundry's garden
with support for rootless.
[#156343575]
Signed-off-by: Claudia Beresford <cberesford@pivotal.io>
