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authorAlexei Starovoitov <ast@kernel.org>2021-11-10 09:25:56 -0800
committerDaniel Borkmann <daniel@iogearbox.net>2021-11-12 16:19:40 +0100
commit34d11a440c6167133201b7374065b59f259730d7 (patch)
tree668f5685d99490a5db621c97cf3c6f68a4529642 /kernel/bpf
parent199d983bc01513173dd9cc486dbddf4d0e414d42 (diff)
bpf: Fix inner map state pruning regression.
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
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 890b3ec375a3..aab7482ed1c3 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1151,7 +1151,8 @@ 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 ||