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authorJakub Kicinski <jakub.kicinski@netronome.com>2019-11-01 06:07:00 +0300
committerDavid S. Miller <davem@davemloft.net>2019-11-02 01:16:01 +0300
commitaefc3e723a78c2e429a64dadd7815ef2a4aecd44 (patch)
treeb063451b5cf5c6ab727b3dfdf36f7763d4574f03
parent41aa29a58b5f7f7be43f35372ef411f304a87a0d (diff)
downloadlinux-aefc3e723a78c2e429a64dadd7815ef2a4aecd44.tar.xz
net: fix installing orphaned programs
When netdevice with offloaded BPF programs is destroyed the programs are orphaned and removed from the program IDA - their IDs get released (the programs may remain accessible via existing open file descriptors and pinned files). After IDs are released they are set to 0. This confuses dev_change_xdp_fd() because it compares the __dev_xdp_query() result where 0 means no program with prog->aux->id where 0 means orphaned. dev_change_xdp_fd() would have incorrectly returned success even though it had not installed the program. Since drivers already catch this case via bpf_offload_dev_match() let them handle this case. The error message drivers produce in this case ("program loaded for a different device") is in fact correct as the orphaned program must had to be loaded for a different device. Fixes: c14a9f633d9e ("net: Don't call XDP_SETUP_PROG when nothing is changed") Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/core/dev.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 96afd464284a..99ac84ff398f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -8421,7 +8421,8 @@ int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
return -EINVAL;
}
- if (prog->aux->id == prog_id) {
+ /* prog->aux->id may be 0 for orphaned device-bound progs */
+ if (prog->aux->id && prog->aux->id == prog_id) {
bpf_prog_put(prog);
return 0;
}