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=... -------------------------------- 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 fa49529682ce..c20f69a4c5e9 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -2661,6 +2661,9 @@ static int gsmld_open(struct tty_struct *tty) { struct gsm_mux *gsm; + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + if (tty->ops->write == NULL) return -EINVAL; -- 2.34.1