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bpf: fix map not being uncharged during map creation failure

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commit 20b2b24f91f70e7d3f0918c077546cb21bd73a87 upstream.

In map_create(), we first find and create the map, then once that
suceeded, we charge it to the user's RLIMIT_MEMLOCK, and then fetch
a new anon fd through anon_inode_getfd(). The problem is, once the
latter fails f.e. due to RLIMIT_NOFILE limit, then we only destruct
the map via map->ops->map_free(), but without uncharging the previously
locked memory first. That means that the user_struct allocation is
leaked as well as the accounted RLIMIT_MEMLOCK memory not released.
Make the label names in the fix consistent with bpf_prog_load().

Fixes: aaac3ba95e4c ("bpf: charge user for creation of BPF maps and programs")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Daniel Borkmann 2016-11-04 00:56:31 +01:00 committed by Greg Kroah-Hartman
parent 529e188d89
commit 445c31d813
1 changed files with 3 additions and 1 deletions
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4
kernel/bpf/syscall.c
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@ -152,7 +152,7 @@ static int map_create(union bpf_attr *attr)
err = bpf_map_charge_memlock(map);
if (err)
goto free_map;
goto free_map_nouncharge;
err = bpf_map_new_fd(map);
if (err < 0)
@ -162,6 +162,8 @@ static int map_create(union bpf_attr *attr)
return err;
free_map:
bpf_map_uncharge_memlock(map);
free_map_nouncharge:
map->ops->map_free(map);
return err;
}