netdev - [PATCH bpf 2/2] bpf: Do not allow map_freeze in struct

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200305013454.535397-1-kafai@fb.com>
Date:   Wed, 4 Mar 2020 17:34:54 -0800
From:   Martin KaFai Lau <kafai@...com>
To:     <bpf@...r.kernel.org>
CC:     Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        David Miller <davem@...emloft.net>, <kernel-team@...com>,
        <netdev@...r.kernel.org>
Subject: [PATCH bpf 2/2] bpf: Do not allow map_freeze in struct_ops map

struct_ops map cannot support map_freeze.  Otherwise, a struct_ops
cannot be unregistered from the subsystem.

Fixes: 85d33df357b6 ("bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS")
Signed-off-by: Martin KaFai Lau <kafai@...com>
---
 kernel/bpf/syscall.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index a91ad518c050..0c7fb0d4836d 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1510,6 +1510,11 @@ static int map_freeze(const union bpf_attr *attr)
 	if (IS_ERR(map))
 		return PTR_ERR(map);
 
+	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
+		fdput(f);
+		return -ENOTSUPP;
+	}
+
 	mutex_lock(&map->freeze_mutex);
 
 	if (map->writecnt) {
-- 
2.17.1