diff --git a/tools-virtiofsd-Add-rseq-syscall-to-the-seccomp-allo.patch b/tools-virtiofsd-Add-rseq-syscall-to-the-seccomp-allo.patch new file mode 100644 index 0000000..b59ef0f --- /dev/null +++ b/tools-virtiofsd-Add-rseq-syscall-to-the-seccomp-allo.patch @@ -0,0 +1,58 @@ +From 5ca1beec7030b5d9fea36eb4f037d4e0e6c260bd Mon Sep 17 00:00:00 2001 +From: Christian Ehrhardt +Date: Wed, 9 Feb 2022 12:14:56 +0100 +Subject: [PATCH] tools/virtiofsd: Add rseq syscall to the seccomp allowlist + +The virtiofsd currently crashes when used with glibc 2.35. +That is due to the rseq system call being added to every thread +creation [1][2]. + +[1]: https://www.efficios.com/blog/2019/02/08/linux-restartable-sequences/ +[2]: https://sourceware.org/pipermail/libc-alpha/2022-February/136040.html + +This happens not at daemon start, but when a guest connects + + /usr/lib/qemu/virtiofsd -f --socket-path=/tmp/testvfsd -o sandbox=chroot \ + -o source=/var/guests/j-virtiofs --socket-group=kvm + virtio_session_mount: Waiting for vhost-user socket connection... + # start ok, now guest will connect + virtio_session_mount: Received vhost-user socket connection + virtio_loop: Entry + fv_queue_set_started: qidx=0 started=1 + fv_queue_set_started: qidx=1 started=1 + Bad system call (core dumped) + +We have to put rseq on the seccomp allowlist to avoid that the daemon +is crashing in this case. + +Reported-by: Michael Hudson-Doyle +Signed-off-by: Christian Ehrhardt +Reviewed-by: Dr. David Alan Gilbert +Message-id: 20220209111456.3328420-1-christian.ehrhardt@canonical.com + +[Moved rseq to its alphabetically ordered position in the seccomp +allowlist. +--Stefan] +Signed-off-by: Stefan Hajnoczi +Signed-off-by: qinyu +--- + tools/virtiofsd/passthrough_seccomp.c | 3 +++ + 1 file changed, 3 insertions(+) + +diff --git a/tools/virtiofsd/passthrough_seccomp.c b/tools/virtiofsd/passthrough_seccomp.c +index a3ce9f898d..2bc0127b69 100644 +--- a/tools/virtiofsd/passthrough_seccomp.c ++++ b/tools/virtiofsd/passthrough_seccomp.c +@@ -91,6 +91,9 @@ static const int syscall_allowlist[] = { + SCMP_SYS(renameat2), + SCMP_SYS(removexattr), + SCMP_SYS(restart_syscall), ++#ifdef __NR_rseq ++ SCMP_SYS(rseq), /* required since glibc 2.35 */ ++#endif + SCMP_SYS(rt_sigaction), + SCMP_SYS(rt_sigprocmask), + SCMP_SYS(rt_sigreturn), +-- +2.27.0 +