From bd454200664173ace6867edc55b14dd45bb00b26 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Wed, 10 Nov 2021 09:25:56 -0800 Subject: [PATCH] bpf: Fix inner map state pruning regression. [ Upstream commit 34d11a440c6167133201b7374065b59f259730d7 ] Introduction of map_uid made two lookups from outer map to be distinct. That distinction is only necessary when inner map has an embedded timer. Otherwise it will make the verifier state pruning to be conservative which will cause complex programs to hit 1M insn_processed limit. Tighten map_uid logic to apply to inner maps with timers only. Fixes: 3e8ce29850f1 ("bpf: Prevent pointer mismatch in bpf_timer_init.") Reported-by: Lorenz Bauer Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann Tested-by: Lorenz Bauer Link: https://lore.kernel.org/bpf/CACAyw99hVEJFoiBH_ZGyy=+oO-jyydoz6v1DeKPKs2HVsUH28w@mail.gmail.com Link: https://lore.kernel.org/bpf/20211110172556.20754-1-alexei.starovoitov@gmail.com Signed-off-by: Sasha Levin --- kernel/bpf/verifier.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index ddba80554fef3..cba37d83451eb 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1143,7 +1143,8 @@ static void mark_ptr_not_null_reg(struct bpf_reg_state *reg) /* transfer reg's id which is unique for every map_lookup_elem * as UID of the inner map. */ - reg->map_uid = reg->id; + if (map_value_has_timer(map->inner_map_meta)) + reg->map_uid = reg->id; } else if (map->map_type == BPF_MAP_TYPE_XSKMAP) { reg->type = PTR_TO_XDP_SOCK; } else if (map->map_type == BPF_MAP_TYPE_SOCKMAP || -- 2.30.2