From ac8014ef399ece930ba5af04947746e62ff00302 Mon Sep 17 00:00:00 2001 From: Ilya Maximets Date: Tue, 12 Mar 2024 01:50:46 +0100 Subject: [PATCH] github: Reduce ASLR entropy to be compatible with asan in llvm 14. Starting with image version 20240310.1.0, GitHub runners are using 32-bit entropy for ASLR: $ sudo sysctl -a | grep vm.mmap.rnd vm.mmap_rnd_bits = 32 vm.mmap_rnd_compat_bits = 16 This breaks all the asan-enabled builds, because older asan gets confused by memory mappings and crashes with segmentation fault. The issue is fixed in newer releases of llvm: https://github.com/llvm/llvm-project/commit/fb77ca05ffb4f8e666878f2f6718a9fb4d686839 https://reviews.llvm.org/D148280 But these are not available in Ubuntu 22.04 image. This should be fixed by GitHub, but until new images are available reducing ASLR entropy manually to 28 bits to make builds work. Reported-at: https://github.com/actions/runner-images/issues/9491 Acked-by: Eelco Chaudron Acked-by: Dumitru Ceara Acked-by: Aaron Conole Signed-off-by: Ilya Maximets --- .github/workflows/build-and-test.yml | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/.github/workflows/build-and-test.yml b/.github/workflows/build-and-test.yml index ade24abc8ce..a75bce6417b 100644 --- a/.github/workflows/build-and-test.yml +++ b/.github/workflows/build-and-test.yml @@ -197,6 +197,14 @@ jobs: if: matrix.m32 != '' run: sudo apt install -y gcc-multilib + - name: Reduce ASLR entropy + if: matrix.asan != '' || matrix.ubsan != '' + # Asan in llvm 14 provided in ubuntu-22.04 is incompatible with + # high-entropy ASLR configured in much newer kernels that GitHub + # runners are using leading to random crashes: + # https://github.com/actions/runner-images/issues/9491 + run: sudo sysctl -w vm.mmap_rnd_bits=28 + - name: prepare run: ./.ci/linux-prepare.sh