This patch series introduces the --rlimit-nofile=NUM option for setting the number of open files on the virtiofsd process. This gives users and management tools more control over resource limits.
Previously it was possible for FUSE clients on machines with less than ~10 GB of RAM to exhaust the system-wide open file limit. This is a denial of service attack against other processes running on the host. This patch series updates the default RLIMIT_NOFILE calculation to take the fs.file-max sysctl value into account. This solves the fs.file-max DoS. Stefan Hajnoczi (2): virtiofsd: add --rlimit-nofile=NUM option virtiofsd: stay below fs.file-max sysctl value (CVE-2020-10717) tools/virtiofsd/fuse_lowlevel.h | 1 + tools/virtiofsd/helper.c | 47 ++++++++++++++++++++++++++++++++ tools/virtiofsd/passthrough_ll.c | 22 ++++++--------- 3 files changed, 56 insertions(+), 14 deletions(-) -- 2.25.3
