Apple specifically acknowledges this and has Lockdown Mode to address it. If you care about security you should enable it. Of course you’ll not be able to watch YouTube videos, but you’ll be safer.
whats the point of carrying phone that doesn't even play youtube videos? If security is so important then they should probably carry nokia style 2000's phone where there is no chance of malaware?
I don’t think Lockdown Mode actually prevents you from watching YouTube videos. Some googling suggests that there might be issues when using the YouTube website in Safari – which makes sense, since Lockdown Mode disables a bunch of Safari features. But the YouTube app probably still works. (I haven’t tried though.)
The only reason the author’s definition doesn’t apply to larger and smaller angles is that they explicitly considered the angles <ABC and <CBA to be equal rather than negatives of each other. That was a surprisingly odd oversight given that they immediately start talking about negative angles.
> Are all names in Mathematica really all together in a single namespace?
No, there are package namespaces (Contexts) like most languages. When you import a package (call Needs) it adds that package’s namespace to the namespace path ($ContextPath).
It's part of a test program used for feature detection (of a sandboxing functionality), and causes a syntax error. That in turn causes the test program to fail to compile, which makes the configure script assume that the sandboxing function is unavailable, and disables support for it.
You are looking at a makefile, not C. The C code is in a string that is being passed to a function called `check_c_source_compiles()`, and this dot makes that code not compile when it should have -- which sets a boolean incorrectly, which presumably makes the build do something it should not do.
This is something that should have unit/integration tests inside the tooling itself, yeah. If your assertion is that X function is called / in the environment X then the function should return Y then that should be a test especially when it’s load-bearing for security.
And tooling is no exception either. You should have tests that your tooling does the things it says on the tin and that things happen when flags are set and things don’t happen when they’re not set, and that the tooling sets the flags in the way you expect.
These aren’t even controversial statements in the JVM world etc. Just C tooling is largely still living in the 70s apart from abortive attempts to build the jenga tower even taller like autotools/autoconf/cmake/etc (incomprehensible, may god have mercy on your build). At least hand written make files are comprehensible tbh.
As far as I can tell, the check is to see if a certain program compiles, and if so, disable something. The dot makes it so that it always fails to compile and thus always disables that something.
> if a certain program compiles, and if so, disable something.
Tiny correction: [...] enable something.
The idea is: If that certain program does not compile it is because something is not available on the system and therefore needs to be disabled.
That dot undermines that logic. The program fails because of a syntax error caused by the dot and not because something is missing.
It is easy to overlook because that dot is tiny and there are many such tests.
I had a similar problem with unit testing of a library. Expected failures need to be tested as well. As an example imagine writing a matrix inversion library. Then you need to verify that you get something like a division by zero error if you invert the zero matrix. You write a unit test for that and by mistake you insert a syntax error. Then you run the unit test and it fails as expected but not in the correct way.
It's subtle. It fails as expected but it fails because of unexpected wrong causes.
The desire for "does this compile on this platform" checks comes from an era where there was pretty much no way to check the error. Somebody runs it on HP-UX with the "HP-UX Ansi C Compiler" they licensed from HP and the error it spits out isn't going to look like anything you recognize.
That one's a separate attack vector, which is seemingly unused in the sshd attack. It only disables sandboxing of the xzdec(2) utility, which is not used in the sshd attack.
I guess xzdec was supposed to sandbox itself where possible so they disabled the sandbox feature check in the build system so that future payload exploits passed to xzdec wouldn’t have to escape the sandbox in order to do anything useful?
Yes, but don't forget that there are different kinds of sandboxes. SELinux never needs the cooperation of any program running on the system in order to correctly sandbox things. No change to Xz could ever make SELinux less effective.
But don't forget that xz is also used as part of dpkg for unpacking packages.
The whole purpose of dpkg is to update critical system packages. Any SELinux policy that protects from a backdoored dpkg/xz installing a rootkit during the next kernel security update; will also prevent installing real kernel security updates.
The particular way of attack in this OpenSSH backdoor can maybe be prevented; but we've got to realize that the attacker already had full root permissions and there's no way of protecting from that.
SELinux policies are much more subtle than that. You don’t restrict what xz or liblzma can do, you restrict what the whole process can do. That process is either sshd or dpkg, and you can give them completely different access to the system, so that if dpkg tries to launch an interactive shell it fails, while sshd fails if it tries to overwrite a system file such as /bin/login or whatever. Neither would ordinarily do that, but the payload delivered via the back door might attempt it and wouldn’t succeed. And you would get a report stating what had happened, so if you’re paying attention the back door starts to become obvious.
Also I think dpkg switched to Zstd, didn’t it? Or am I misremembering?
But you’re not wrong; ultimately both sshd and dpkg are critical infrastructure. SELinux can prevent them from doing completely wrong things, but obviously it wouldn’t be useful for it to prevent them from doing their jobs. And those jobs are security critical already. SELinux is not a panacea, merely defense in depth.
But that's a check for a Linux feature. So the more interesting question would be, what in the Linux world might be building xz-utils with cmake, I guess using ExternalProject_Add or something similar.
No, you can cache some of the work you did when processing the previous tokens. This is one of the key optimization ideas designed into the architecture.
I too have been with AT&T since the Cingular merger and am also not in the HIBP db. I use a custom email address related to Cingular, which I otherwise would have forgotten existed.
I've been with AT&T forever, I've used a custom email address for AT&T since forever, and my email address is also not in the dump (I have a Premier account.)
For those wondering about why the \, is used to indicate the start a lisp expression, the backslash is used to escape all replacements and the comma recalls the lisp backquote (`) function (operator) which is like quote (‘), but allows interpolation of evaluated lisp expressions when preceded by a comma[0].
Don't suppose if you know if the conversion is easily reversible? Some of these models are big, it sucks to carry around the original plus the gguf, but I would hate to be in a situation where the gguf represents a dead end.
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