Messages in this thread | | | From | Alexander Potapenko <> | Date | Tue, 24 Jan 2023 12:07:23 +0100 | Subject | Re: [syzbot] KMSAN: uninit-value in longest_match |
| |
> > Can't we just pass __GFP_ZERO when allocating the workspace here: > > > > ... > > This is what Chrome folks did in the same situation ( > > https://chromium.googlesource.com/chromium/src.git/+/962cbbe81708214ff8e14e2bc8a07271cb15f1b9 > > ) > > Sure, the btrfs folks can do that if they want to avoid this warning for the > btrfs zlib compression specifically. This would not solve the issue for the > other users of zlib compression in the kernel.
We probably can't fix zlib without sacrificing performance, so I think the right thing to do is to actually modify the users of zlib compression to pass only initialized data to zlib. Doing so will make the calls to zlib_deflate() well-defined, whereas marking longest_match() as buggy will just hide future error reports, but won't fix the code in question.
| |