From 770ca94f54d2cfe2cbd9b10ae441578f82df84d8 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 21 Feb 2019 10:40:14 -0800 Subject: [PATCH] UPSTREAM: seccomp, bpf: disable preemption before calling into bpf prog All BPF programs must be called with preemption disabled. Fixes: 568f196756ad ("bpf: check that BPF programs run with preemption disabled") Reported-by: syzbot+8bf19ee2aa580de7a2a7@syzkaller.appspotmail.com Change-Id: Ia5fa93009d0e31261eab2890b435730f4e310c6a Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann --- kernel/seccomp.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/seccomp.c b/kernel/seccomp.c index da34e800a398..642078429313 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -210,6 +210,7 @@ static u32 seccomp_run_filters(const struct seccomp_data *sd, * All filters in the list are evaluated and the lowest BPF return * value always takes priority (ignoring the DATA). */ + preempt_disable(); for (; f; f = f->prev) { u32 cur_ret = BPF_PROG_RUN(f->prog, sd); @@ -218,6 +219,7 @@ static u32 seccomp_run_filters(const struct seccomp_data *sd, *match = f; } } + preempt_enable(); return ret; } #endif /* CONFIG_SECCOMP_FILTER */