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authorAlexei Starovoitov <ast@kernel.org>2021-11-10 20:25:56 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-11-25 11:48:33 +0300
commitbd454200664173ace6867edc55b14dd45bb00b26 (patch)
tree1c57c8d7a091a3c02a8c8796c85c74f28731cd88 /kernel/bpf
parent8369b01aa5a6eedcc32ca06d3a5057811c0d8889 (diff)
downloadlinux-bd454200664173ace6867edc55b14dd45bb00b26.tar.xz
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 <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Lorenz Bauer <lmb@cloudflare.com> 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 <sashal@kernel.org>
Diffstat (limited to 'kernel/bpf')
-rw-r--r--kernel/bpf/verifier.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index ddba80554fef..cba37d83451e 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 ||