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authorStanislav Fomichev <sdf@google.com>2020-10-02 17:25:44 -0700
committerAlexei Starovoitov <ast@kernel.org>2020-10-02 19:21:25 -0700
commit1028ae4069991e26d1522e957939fb61d2da1d12 (patch)
tree3515e99b6d9dafa966d02e423f092d6379d7998f /kernel/bpf/syscall.c
parentfb91db01c652ba9391f67c21db2d5260448b3efd (diff)
bpf: Deref map in BPF_PROG_BIND_MAP when it's already used
We are missing a deref for the case when we are doing BPF_PROG_BIND_MAP on a map that's being already held by the program. There is 'if (ret) bpf_map_put(map)' below which doesn't trigger because we don't consider this an error. Let's add missing bpf_map_put() for this specific condition. Fixes: ef15314aa5de ("bpf: Add BPF_PROG_BIND_MAP syscall") Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20201003002544.3601440-1-sdf@google.com
Diffstat (limited to 'kernel/bpf/syscall.c')
-rw-r--r--kernel/bpf/syscall.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index f1528c2a6927..1110ecd7d1f3 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -4323,8 +4323,10 @@ static int bpf_prog_bind_map(union bpf_attr *attr)
used_maps_old = prog->aux->used_maps;
for (i = 0; i < prog->aux->used_map_cnt; i++)
- if (used_maps_old[i] == map)
+ if (used_maps_old[i] == map) {
+ bpf_map_put(map);
goto out_unlock;
+ }
used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
sizeof(used_maps_new[0]),