From: Thadeu Lima de Souza Cascardo cascardo@canonical.com
stable inclusion from stable-v5.10.215 commit ada28eb4b9561aab93942f3224a2e41d76fe57fa category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9S26U CVE: CVE-2023-52880
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 67c37756898a5a6b2941a13ae7260c89b54e0d88 upstream.
Any unprivileged user can attach N_GSM0710 ldisc, but it requires CAP_NET_ADMIN to create a GSM network anyway.
Require initial namespace CAP_NET_ADMIN to do that.
Signed-off-by: Thadeu Lima de Souza Cascardo cascardo@canonical.com Link: https://lore.kernel.org/r/20230731185942.279611-1-cascardo@canonical.com Cc: Salvatore Bonaccorso carnil@debian.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Xiang Yang xiangyang3@huawei.com --- drivers/tty/n_gsm.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 6cd87e71fecc..96a5e0f91c15 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -2619,6 +2619,9 @@ static int gsmld_open(struct tty_struct *tty) struct gsm_mux *gsm; int ret;
+ if (!capable(CAP_NET_ADMIN)) + return -EPERM; + if (tty->ops->write == NULL) return -EINVAL;