tfw hardware becoming so unreliable people start using 32-bit maximum distance codes for enumerations with like four values.
Try to make sudo less vulnerable to Rowhammer attacks
11–20 of 147 posts
Re: Try to make sudo less vulnerable to Rowhammer attacks
#12[flagged]
Re: Try to make sudo less vulnerable to Rowhammer attacks
#13Is there any reason for the void cast here? Theres no return value in use. (void)strlcpy(des_pass, pass,sizeof(des_pass));
strlcpy returns a size_t, so just to silence the discarded return value warning
Re: Try to make sudo less vulnerable to Rowhammer attacks
#14Couldn't compilers be configured to use such values for for any enum type? And maybe even auto-insert the appropriate check in the final unchecked else anywhere that enum type is otherwise exhaustively checked?
Yes it's possible, but it's not desirable. It wouldn't be backwards compatible, and not safe for shared libraries. It's better suited for a linter-type error/warning.
It's not plausible in C, for the reasons you mention, but it might be more possible in other languages -- Rust, for example, only guarantees specific representations when instructed and doesn't allow for shared libraries without a specified representation, so it wouldn't have either issue for most application code. Dynamically-typed languages similarly should be able to choose enum values at runtime in many cases.
Re: Try to make sudo less vulnerable to Rowhammer attacks
#15[flagged]
Rust makes a particular class of bugs harder to write. That’s it. It doesn’t magically eliminate all bugs. “Susceptible to rowhammer” is not in the class of bugs that Rust helps with.
No experienced Rust programmer actually believes it magically prevents all bugs or magically makes security-sensitive code immune to side channel attacks, so I don’t think anyone is being lulled into a false sense of security, no.
Re: Try to make sudo less vulnerable to Rowhammer attacks
#16[flagged]
Rust makes a particular class of bugs harder to write. That’s it. It doesn’t magically eliminate all bugs. “Susceptible to rowhammer” is not in the class of bugs that Rust helps with. No experienced Rust programmer actually believes it magically prevents all bugs or magically makes security-sensitive code immune to side channel attacks, so I don’t think anyone is being lulled into a false sense of security, no.
What about the Non-experienced Rust programmer? A lot of open source code are written by inexperienced people who understand the nuances of computer science primarily through hype. I think those are the kinds of people OP was asking about.
Re: Try to make sudo less vulnerable to Rowhammer attacks
#17Earlier quoted context omitted.
Rust makes a particular class of bugs harder to write. That’s it. It doesn’t magically eliminate all bugs. “Susceptible to rowhammer” is not in the class of bugs that Rust helps with. No experienced Rust programmer actually believes it magically prevents all bugs or magically makes security-sensitive code immune to side channel attacks, so I don’t think anyone is being lulled into a false sense of security, no.
What about the Non-experienced Rust programmer? A lot of open source code are written by inexperienced people who understand the nuances of computer science primarily through hype. I think those are the kinds of people OP was asking about.
That’s not a rust problem. Misunderstanding and misusing a tool is an inexperienced person problem. It’s one thing you pay veterans more for.
Re: Try to make sudo less vulnerable to Rowhammer attacks
#18Feels like a language with opaque enums and pattern matching could implement this kind of thing behind the scenes.
Re: Try to make sudo less vulnerable to Rowhammer attacks
#19I thought that Rowhammer was a thing of the past. Out of curiosity I found code to test for this and ran it on some of my hosts. My old desktop - I7-4770K/DDR3 - was susceptible. My old server - Xeon X3460/DDR3+ECC - was not. I upgraded the desktop with components based on a Ryzen 7 7700X/DDR5. It tested not susceptible. I'm not sure if that's a result of RAM designed not to be susceptible or that (I think) DDR5 RAM uses modules with on die ECC.
I was not able to test any of my Raspberry Pis because the test code used some facility available on the AMD64 architecture that is not available on the ARM64 processors. The newer Pi 4B and 5 use modules with on die ECC.
It seems to me that ECC should prevent Rowhammer susceptibility. That should prevent it on server grade H/W for anything still in service and newer consumer systems.
I have no idea if Rowhammer affects other architectures than AMD64.
Re: Try to make sudo less vulnerable to Rowhammer attacks
#20I thought that Rowhammer was a thing of the past. Out of curiosity I found code to test for this and ran it on some of my hosts. My old desktop - I7-4770K/DDR3 - was susceptible. My old server - Xeon X3460/DDR3+ECC - was not. I upgraded the desktop with components based on a Ryzen 7 7700X/DDR5. It tested not susceptible. I'm not sure if that's a result of RAM designed not to be susceptible or that (I think) DDR5 RAM…
Rowhammer is not architecture specific, since it's the DRAM rather than the CPU.
The paper linked in the patch references other works showing every defence at rowhammer can be bypassed somehow (I've not followed them all) - e.g. it specifically says that ECC and the like can be bypassed.