A deletion of a hardif from a batadv meshif will also get a success reply from the kernel when the hardif was never part of the batadv meshif. If the batadv meshif had no attached hardifs before the removal was started, then users are then not expecting that the batadv meshif is removed at all.
Since the delete operation is not an atomic compare-and-swap operation, just check first the number of attached interfaces and only start the removal of the batadv meshif when the number attached hardifs was reduced.
Fixes: 25022e0b154d ("batctl: Use rtnl to add/remove interfaces") Reported-by: Matthias Schiffer mschiffer@universe-factory.net Signed-off-by: Sven Eckelmann sven@narfation.org --- interface.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/interface.c b/interface.c index 1cd6ede..ac4d883 100644 --- a/interface.c +++ b/interface.c @@ -386,6 +386,7 @@ static int interface(struct state *state, int argc, char **argv) int ret; unsigned int ifindex; unsigned int ifmaster; + unsigned int pre_cnt; const char *long_op; unsigned int cnt; int rest_argc; @@ -502,6 +503,8 @@ static int interface(struct state *state, int argc, char **argv) goto err; }
+ pre_cnt = count_interfaces(state->mesh_iface); + for (i = 1; i < rest_argc; i++) { ifindex = if_nametoindex(rest_argv[i]);
@@ -531,7 +534,7 @@ static int interface(struct state *state, int argc, char **argv) /* check if there is no interface left and then destroy mesh_iface */ if (!manual_mode && rest_argv[0][0] == 'd') { cnt = count_interfaces(state->mesh_iface); - if (cnt == 0) + if (cnt == 0 && pre_cnt > 0) destroy_interface(state->mesh_iface); }