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The thing about being able to read other process memory under Linux has always driven me nuts. Linux is fairly secure _except_ for this one giant gaping hole t
by thrownaway2424 11y ago
The thing about being able to read other process memory under Linux has always driven me nuts. Linux is fairly secure _except_ for this one giant gaping hole that nobody mentions.
- 0x0 11y agoThis is extra fun considering WebGL.
- hiker 11y agoWebGL implementations zero out newly allocated buffers for exactly that reason. https://www.khronos.org/registry/webgl/specs/latest/1.0/#4 https://www.khronos.org/registry/webgl/specs/latest/1.0/#4
- TheLoneWolfling 11y agoHow long until we get a heartbleed-like attack where some software overruns its GPU buffer into a webgl buffer?
- MaulingMonkey 11y agoFWIW I've been running with WebGL disabled because of similar concerns.
- thrownaway2424 11y agoWebGL works if you enable it? On Linux I've never seen anything other than error messages from WebGL.
- thristian 11y agoWebGL exercises some new corners of the OpenGL interface that many drivers weren't prepared for when WebGL arrived, so browsers tend to have an extensive blacklist: if you have a driver on the list, you won't get WebGL. On a rolling release like Debian Testing, with well-supported hardware like the Intel Ivy Bridge integrated GPU, WebGL has always worked beautifully.
- gkop 11y agoYou can try overriding the blacklist in Chrome, that worked well for me when I needed to for a Debian/Nvidia system a couple years ago.
- MaulingMonkey 11y agoAhh, I've been disabling it on Windows, however silly that might be.
- rbanffy 11y agoShould be pretty straightforward to fix. I wonder why it isn't. Is someone discussing the issue?
- deleted 11y ago[deleted]
- sliverstorm 11y agoKnowing nothing about the issue, I speculate many programs have come to depend on the behavior. Similar to antique bugs in x86 that were baked in to the architecture when programmers had to work with them on the 286 & 386. After that they couldn't be fixed because programs depended on the presence of the bug.
- 0x0 11y agoI'm having a very hard time imagining there exists even a single program out there that depends on being able to read the memory contents of a program that ran before itself. I bet it comes down to driver developers never even thinking that this could be a security issue before people came up with the concept of running unauthenticated 3d accelerated software (i.e. javascript+webgl from the network in a browser) - "what do you mean security, the user could just have taken a screenshot at any time. why should we waste precious FPS clearing buffers when the program will fill in its own textures before drawing anything".
- tbirdz 11y ago> I'm having a very hard time imagining there exists even a single program out there that depends on being able to read the memory contents of a program that ran before itself. gdb, when using it to attach to an already running process.
- 0x0 11y agoNot exactly, GDB would be accessing memory that is still allocated. I think the OP was referring to accessing memory contents from deallocated regions. Also we're talking GPU memory here, for the most part. :)
- sidarape 11y agoCare to provide a link explanning this?
- deleted 11y ago[deleted]