`Elf*_Rela` relocations store their argument in `r_addend`, including for `R_*_RELATIVE` relocations. Unlike `Elf*_Rel` relocations, they are not applied as a delta to the destination virtual address. Instead, they are computed from `base_address + r_addend` directly.
We are posting two submission (zero copy send and receive) and then
reading two completions. There is no guarantee that those completions
will be in the order of submissions.
This test was expecting fist send completion then receive.
Fix is allowing them to come other way too.
- From lib/libc/include/any-windows-any/wincon.h#L235
- See also https://learn.microsoft.com/en-us/windows/console/setconsolemode
- Also add DISABLE_NEWLINE_AUTO_RETURN constant which will be used by SetConsoleMode in lib/std/os/windows.
Co-authored-by: Kexy Biscuit <kexybiscuit@biscuitt.in>
A volume can be mounted as a NTFS path, e.g. as C:\Mnt\Foo. In that case, IOCTL_MOUNTMGR_QUERY_POINTS gives us a mount point with a symlink value something like `\??\Volume{383da0b0-717f-41b6-8c36-00500992b58d}`. In order to get the `C:\Mnt\Foo` path, we can query the mountmgr again using IOCTL_MOUNTMGR_QUERY_DOS_VOLUME_PATH.
Fixes#19731
> Note: This first part is mostly a rephrasing of https://flatt.tech/research/posts/batbadbut-you-cant-securely-execute-commands-on-windows/
> See that article for more details
On Windows, it is possible to execute `.bat`/`.cmd` scripts via CreateProcessW. When this happens, `CreateProcessW` will (under-the-hood) spawn a `cmd.exe` process with the path to the script and the args like so:
cmd.exe /c script.bat arg1 arg2
This is a problem because:
- `cmd.exe` has its own, separate, parsing/escaping rules for arguments
- Environment variables in arguments will be expanded before the `cmd.exe` parsing rules are applied
Together, this means that (1) maliciously constructed arguments can lead to arbitrary command execution via the APIs in `std.process.Child` and (2) escaping according to the rules of `cmd.exe` is not enough on its own.
A basic example argv field that reproduces the vulnerability (this will erroneously spawn `calc.exe`):
.argv = &.{ "test.bat", "\"&calc.exe" },
And one that takes advantage of environment variable expansion to still spawn calc.exe even if the args are properly escaped for `cmd.exe`:
.argv = &.{ "test.bat", "%CMDCMDLINE:~-1%&calc.exe" },
(note: if these spawned e.g. `test.exe` instead of `test.bat`, they wouldn't be vulnerable; it's only `.bat`/`.cmd` scripts that are vulnerable since they go through `cmd.exe`)
Zig allows passing `.bat`/`.cmd` scripts as `argv[0]` via `std.process.Child`, so the Zig API is affected by this vulnerability. Note also that Zig will search `PATH` for `.bat`/`.cmd` scripts, so spawning something like `foo` may end up executing `foo.bat` somewhere in the PATH (the PATH searching of Zig matches the behavior of cmd.exe).
> Side note to keep in mind: On Windows, the extension is significant in terms of how Windows will try to execute the command. If the extension is not `.bat`/`.cmd`, we know that it will not attempt to be executed as a `.bat`/`.cmd` script (and vice versa). This means that we can just look at the extension to know if we are trying to execute a `.bat`/`.cmd` script.
---
This general class of problem has been documented before in 2011 here:
https://learn.microsoft.com/en-us/archive/blogs/twistylittlepassagesallalike/everyone-quotes-command-line-arguments-the-wrong-way
and the course of action it suggests for escaping when executing .bat/.cmd files is:
- Escape first using the non-cmd.exe rules
- Then escape all cmd.exe 'metacharacters' (`(`, `)`, `%`, `!`, `^`, `"`, `<`, `>`, `&`, and `|`) with `^`
However, escaping with ^ on its own is insufficient because it does not stop cmd.exe from expanding environment variables. For example:
```
args.bat %PATH%
```
escaped with ^ (and wrapped in quotes that are also escaped), it *will* stop cmd.exe from expanding `%PATH%`:
```
> args.bat ^"^%PATH^%^"
"%PATH%"
```
but it will still try to expand `%PATH^%`:
```
set PATH^^=123
> args.bat ^"^%PATH^%^"
"123"
```
The goal is to stop *all* environment variable expansion, so this won't work.
Another problem with the ^ approach is that it does not seem to allow all possible command lines to round trip through cmd.exe (as far as I can tell at least).
One known example:
```
args.bat ^"\^"key^=value\^"^"
```
where args.bat is:
```
@echo %1 %2 %3 %4 %5 %6 %7 %8 %9
```
will print
```
"\"key value\""
```
(it will turn the `=` into a space for an unknown reason; other minor variations do roundtrip, e.g. `\^"key^=value\^"`, `^"key^=value^"`, so it's unclear what's going on)
It may actually be possible to escape with ^ such that every possible command line round trips correctly, but it's probably not worth the effort to figure it out, since the suggested mitigation for BatBadBut has better roundtripping and leads to less garbled command lines overall.
---
Ultimately, the mitigation used here is the same as the one suggested in:
https://flatt.tech/research/posts/batbadbut-you-cant-securely-execute-commands-on-windows/
The mitigation steps are reproduced here, noted with one deviation that Zig makes (following Rust's lead):
1. Replace percent sign (%) with %%cd:~,%.
2. Replace the backslash (\) in front of the double quote (") with two backslashes (\\).
3. Replace the double quote (") with two double quotes ("").
4. ~~Remove newline characters (\n).~~
- Instead, `\n`, `\r`, and NUL are disallowed and will trigger `error.InvalidBatchScriptArg` if they are found in `argv`. These three characters do not roundtrip through a `.bat` file and therefore are of dubious/no use. It's unclear to me if `\n` in particular is relevant to the BatBadBut vulnerability (I wasn't able to find a reproduction with \n and the post doesn't mention anything about it except in the suggested mitigation steps); it just seems to act as a 'end of arguments' marker and therefore anything after the `\n` is lost (and same with NUL). `\r` seems to be stripped from the command line arguments when passed through a `.bat`/`.cmd`, so that is also disallowed to ensure that `argv` can always fully roundtrip through `.bat`/`.cmd`.
5. Enclose the argument with double quotes (").
The escaped command line is then run as something like:
cmd.exe /d /e:ON /v:OFF /c "foo.bat arg1 arg2"
Note: Previously, we would pass `foo.bat arg1 arg2` as the command line and the path to `foo.bat` as the app name and let CreateProcessW handle the `cmd.exe` spawning for us, but because we need to pass `/e:ON` and `/v:OFF` to cmd.exe to ensure the mitigation is effective, that is no longer tenable. Instead, we now get the full path to `cmd.exe` and use that as the app name when executing `.bat`/`.cmd` files.
---
A standalone test has also been added that tests two things:
1. Known reproductions of the vulnerability are tested to ensure that they do not reproduce the vulnerability
2. Randomly generated command line arguments roundtrip when passed to a `.bat` file and then are passed from the `.bat` file to a `.exe`. This fuzz test is as thorough as possible--it tests that things like arbitrary Unicode codepoints and unpaired surrogates roundtrip successfully.
Note: In order for the `CreateProcessW` -> `.bat` -> `.exe` roundtripping to succeed, the .exe must split the arguments using the post-2008 C runtime argv splitting implementation, see https://github.com/ziglang/zig/pull/19655 for details on when that change was made in Zig.
A pointer type already has an alignment, so this information does not
need to be duplicated on the function type. This already has precedence
with addrspace which is already disallowed on function types for this
reason. Also fixes `@TypeOf(&func)` to have the correct addrspace and
alignment.
This implementation is now a direct replacement for the `kernel32` one.
New bitflags for named pipes and other generic ones were added based on
browsing the ReactOS sources.
`UNICODE_STRING.Buffer` has also been changed to be nullable, as
this is what makes the implementation work.
This required some changes to places accesssing the buffer after a
`SUCCESS`ful return, most notably `QueryObjectName` which even referred
to it being nullable.
* io_uring: ring mapped buffers
Ring mapped buffers are newer implementation of ring provided buffers, supported
since kernel 5.19. Best described in Jens Axboe [post](https://github.com/axboe/liburing/wiki/io_uring-and-networking-in-2023#provided-buffers)
This commit implements low level io_uring_*_buf_ring_* functions as mostly
direct translation from liburing. It also adds BufferGroup abstraction over those
low level functions.
* io_uring: add multishot recv to BufferGroup
Once we have ring mapped provided buffers functionality it is possible to use
multishot recv operation. Multishot receive is submitted once, and completions
are posted whenever data arrives on the socket. Received data are placed in a
new buffer from buffer group.
Reference: [io_uring and networking in 2023](https://github.com/axboe/liburing/wiki/io_uring-and-networking-in-2023#multi-shot)
Getting NOENT for cancel completion result, meaning:
-ENOENT
The request identified by user_data could not be located.
This could be because it completed before the cancelation
request was issued, or if an invalid identifier is used.
https://man7.org/linux/man-pages/man3/io_uring_prep_cancel.3.htmlhttps://github.com/ziglang/zig/actions/runs/6801394000/job/18492139893?pr=17806
Result in cancel/recv cqes are different depending on the kernel.
on older kernel (tested with v6.0.16, v6.1.57, v6.2.12, v6.4.16)
cqe_cancel.err() == .NOENT
cqe_crecv.err() == .NOBUFS
on kernel (tested with v6.5.0, v6.5.7)
cqe_cancel.err() == .SUCCESS
cqe_crecv.err() == .CANCELED
It's been seen on Windows 11 (22H2) Build 22621.3155 that NtCreateFile
will return the OBJECT_NAME_INVALID error code with certain path names.
The path name we saw this with started with `C:Users` (rather than
`C:\Users`) and also contained a `$` character. This PR updates our
OpenFile wrapper to propagate this error code as `error.BadPathName`
instead of making it `unreachable`.
see https://github.com/marler8997/zigup/issues/114#issuecomment-1994420791
* `linux.IO_Uring` -> `linux.IoUring` to align with naming conventions.
* All functions `io_uring_prep_foo` are now methods `prep_foo` on `io_uring_sqe`, which is in a file of its own.
* `SubmissionQueue` and `CompletionQueue` are namespaced under `IoUring`.
This is a breaking change.
The new file and namespace layouts are more idiomatic, and allow us to
eliminate one more usage of `usingnamespace` from the standard library.
2 remain.
Some of the structs I shuffled around might be better namespaced under
CONTEXT, I'm not sure. However, for now, this approach preserves
backwards compatibility.
Eliminates one more usage of `usingnamespace` from the standard library.
3 remain.
This usage of `usingnamespace` was removed fairly trivially - the
resulting code is, IMO, more clear.
Eliminates one more usage of `usingnamespace` from the standard library.
This is a trivial change - this code did `usingnamespace` into an
otherwise empty namespace, so the outer namespace was just unnecessary.
Eliminates one more usage of `usingnamespace` from the standard library.
Follow up to #19079, which made test names fully qualified.
This fixes tests that now-redundant information in their test names. For example here's a fully qualified test name before the changes in this commit:
"priority_queue.test.std.PriorityQueue: shrinkAndFree"
and the same test's name after the changes in this commit:
"priority_queue.test.shrinkAndFree"
Windows paths now use WTF-16 <-> WTF-8 conversion everywhere, which is lossless. Previously, conversion of ill-formed UTF-16 paths would either fail or invoke illegal behavior.
WASI paths must be valid UTF-8, and the relevant function calls have been updated to handle the possibility of failure due to paths not being encoded/encodable as valid UTF-8.
Closes#18694Closes#1774Closes#2565
