Control: tags -1 + confirmed On Sat, 2022-10-08 at 11:30 +0200, Aurelien Jarno wrote: > The glibc/2.31-13+deb11u4 update introduced a regression (bug > #1019855) on some early Intel Haswell processors which expose the > AVX2 instructions, but lack the BMI2 instructions. On such systems > the memchr and strlen related functions fails with SIGILL, rendering > them unusable. > > The issue is that some of the backported commits to fix the overflow > bugs in the AVX2 implementation of wmemchr and wcslen that went in > the upstream 2.31 branch, started to use BMI2 instructions in > addition to the AVX2 instructions, without checking for the > availability of those instructions. This was done in another commit > that hasn't been backported. > > It happens that a microcode update for the affected CPUs (either > through the BIOS/firmware or from a package) fixes this, so it went > barely noticed up to now, especially given other distributions > usually install firmware updates by default. > > [ Impact ] > While the number of affected systems is probably small, this bug > makes them unusable. [...] > Given the severity of the bug, it might be a good idea to release it > through stable-updates.
Please go ahead. Regards, Adam
