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| author | Jakub Kicinski <jakub.kicinski@netronome.com> | 2019-10-31 20:07:00 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-11-01 15:16:01 -0700 |
| commit | aefc3e723a78c2e429a64dadd7815ef2a4aecd44 (patch) | |
| tree | b063451b5cf5c6ab727b3dfdf36f7763d4574f03 | |
| parent | 41aa29a58b5f7f7be43f35372ef411f304a87a0d (diff) | |
| download | lwn-aefc3e723a78c2e429a64dadd7815ef2a4aecd44.tar.gz lwn-aefc3e723a78c2e429a64dadd7815ef2a4aecd44.zip | |
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.c | 3 |
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; } |