kernel/linux.git/net/core/dst.c, branch linux-5.11.y

net, bpf: Fix ip6ip6 crash with collect_md populated skbs

2021-03-30T12:30:27+00:00

[ Upstream commit a188bb5638d41aa99090ebf2f85d3505ab13fba5 ] I ran into a crash where setting up a ip6ip6 tunnel device which was /not/ set to collect_md mode was receiving collect_md populated skbs for xmit. The BPF prog was populating the skb via bpf_skb_set_tunnel_key() which is assigning special metadata dst entry and then redirecting the skb to the device, taking ip6_tnl_start_xmit() -> ipxip6_tnl_xmit() -> ip6_tnl_xmit() and in the latter it performs a neigh lookup based on skb_dst(skb) where we trigger a NULL pointer dereference on dst->ops->neigh_lookup() since the md_dst_ops do not populate neigh_lookup callback with a fake handler. Transform the md_dst_ops into generic dst_blackhole_ops that can also be reused elsewhere when needed, and use them for the metadata dst entries as callback ops. Also, remove the dst_md_discard{,_out}() ops and rely on dst_discard{,_out}() from dst_init() which free the skb the same way modulo the splat. Given we will be able to recover just fine from there, avoid any potential splats iff this gets ever triggered in future (or worse, panic on warns when set). Fixes: f38a9eb1f77b ("dst: Metadata destinations") Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: Consolidate common blackhole dst ops

2021-03-30T12:30:27+00:00

[ Upstream commit c4c877b2732466b4c63217baad05c96f775912c7 ] Move generic blackhole dst ops to the core and use them from both ipv4_dst_blackhole_ops and ip6_dst_blackhole_ops where possible. No functional change otherwise. We need these also in other locations and having to define them over and over again is not great. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: Correct the comment of dst_dev_put()

2020-09-10T20:28:57+00:00

Since commit 8d7017fd621d ("blackhole_netdev: use blackhole_netdev to invalidate dst entries"), we use blackhole_netdev to invalidate dst entries instead of loopback device anymore. Signed-off-by: Miaohe Lin Signed-off-by: David S. Miller

net/dst: use a smaller percpu_counter batch for dst entries accounting

2020-05-09T04:33:33+00:00

percpu_counter_add() uses a default batch size which is quite big on platforms with 256 cpus. (2*256 -> 512) This means dst_entries_get_fast() can be off by +/- 2*(nr_cpus^2) (131072 on servers with 256 cpus) Reduce the batch size to something more reasonable, and add logic to ip6_dst_gc() to call dst_entries_get_slow() before calling the _very_ expensive fib6_run_gc() function. Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski

net: print proper warning on dst underflow

2019-09-26T07:05:56+00:00

Proper warnings with stack traces make it much easier to figure out what's doing the double free and create more meaningful bug reports from users. Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller

blackhole_netdev: use blackhole_netdev to invalidate dst entries

2019-07-02T02:34:46+00:00

Use blackhole_netdev instead of 'lo' device with lower MTU when marking dst "dead". Signed-off-by: Mahesh Bandewar Tested-by: Michael Chan Signed-off-by: David S. Miller

treewide: Add SPDX license identifier for missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

net: dst: remove gc leftovers

2019-03-21T20:39:25+00:00

Get rid of some obsolete gc-related documentation and macros that were missed in commit 5b7c9a8ff828 ("net: remove dst gc related code"). CC: Wei Wang Signed-off-by: Julian Wiedmann Acked-by: Wei Wang Signed-off-by: David S. Miller

net: add a route cache full diagnostic message

2019-01-17T23:37:25+00:00

In some testing scenarios, dst/route cache can fill up so quickly that even an explicit GC call occasionally fails to clean it up. This leads to sporadically failing calls to dst_alloc and "network unreachable" errors to the user, which is confusing. This patch adds a diagnostic message to make the cause of the failure easier to determine. Signed-off-by: Peter Oskolkov Signed-off-by: David S. Miller

netfilter: nf_tables: add tunnel support

2018-08-03T19:12:12+00:00

This patch implements the tunnel object type that can be used to configure tunnels via metadata template through the existing lightweight API from the ingress path. Signed-off-by: Pablo Neira Ayuso