Hello Pablo, I've reproduced the regression:
20241023090545167 DGGSN NOTICE Initialized GTP kernel mode (genl ID is 32) (gtp-kernel.c:80) [ 0.721705] gtp: enable gtp on -1, 4 [ 0.722017] gtp: gtp socket fd=-1 not found 20241023090545169 DTUN ERROR cannot create GTP tunnel device: Bad file descriptor (tun.c:213)
and verified that it is fixed with your patch. Thanks! Best regards, Oliver On 22.10.24 16:48, Pablo Neira Ayuso wrote:
Existing user space applications maintained by the Osmocom project are breaking since a recent fix that addresses incorrect error checking.
Restore operation for user space programs that specify -1 as file descriptor to skip GTPv0 or GTPv1 only sockets.
Fixes: defd8b3c37b0 ("gtp: fix a potential NULL pointer dereference") Reported-by: Pau Espin Pedrol <pespin@sysmocom.de>
Tested-by: Oliver Smith <osmith@sysmocom.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- drivers/net/gtp.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index a60bfb1abb7f..70f981887518 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -1702,20 +1702,24 @@ static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]) return -EINVAL;
if (data[IFLA_GTP_FD0]) { - u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]); + int fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
- sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp); - if (IS_ERR(sk0)) - return PTR_ERR(sk0); + if (fd0 >= 0) { + sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp); + if (IS_ERR(sk0)) + return PTR_ERR(sk0); + } }
if (data[IFLA_GTP_FD1]) { - u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]); + int fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
- sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp); - if (IS_ERR(sk1u)) { - gtp_encap_disable_sock(sk0); - return PTR_ERR(sk1u); + if (fd1 >= 0) { + sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp); + if (IS_ERR(sk1u)) { + gtp_encap_disable_sock(sk0); + return PTR_ERR(sk1u); + } } }
-- - Oliver Smith <osmith@sysmocom.de> https://www.sysmocom.de/ ======================================================================= * sysmocom - systems for mobile communications GmbH * Siemensstr. 26a * 10551 Berlin, Germany * Sitz / Registered office: Berlin, HRB 134158 B * Geschaeftsfuehrer / Managing Director: Harald Welte