[net-next,v1,0/5] Some pktgen fixes/improvments

Message

Peter Seiderer Jan. 17, 2025, 2:16 p.m. UTC

While taking a look at '[PATCH net] pktgen: Avoid out-of-range in
get_imix_entries' ([1]) and '[PATCH net v2] pktgen: Avoid out-of-bounds access
in get_imix_entries' ([2], [3]) and doing some tests and code review I
detected that the /proc/net/pktgen/... parsing logic does not honour the
user given buffer bounds (resulting in out-of-bounds access).

This can be observed e.g. by the following simple test (sometimes the
old/'longer' previous value is re-read from the buffer):

	$ echo add_device lo@0 > /proc/net/pktgen/kpktgend_0

	$ echo "min_pkt_size 12345" > /proc/net/pktgen/lo\@0 && grep min_pkt_size /proc/net/pktgen/lo\@0
Params: count 1000  min_pkt_size: 12345  max_pkt_size: 0
Result: OK: min_pkt_size=12345

	$ echo -n "min_pkt_size 123" > /proc/net/pktgen/lo\@0 && grep min_pkt_size /proc/net/pktgen/lo\@0
Params: count 1000  min_pkt_size: 12345  max_pkt_size: 0
Result: OK: min_pkt_size=12345

	$ echo "min_pkt_size 123" > /proc/net/pktgen/lo\@0 && grep min_pkt_size /proc/net/pktgen/lo\@0
Params: count 1000  min_pkt_size: 123  max_pkt_size: 0
Result: OK: min_pkt_size=123

So fix the out-of-bounds access (and two minor findings) and add a simple
proc_net_pktgen selftest...

Regards,
Peter

[1] https://lore.kernel.org/netdev/[e-mail]/
[2] https://lore.kernel.org/netdev/[e-mail]/
[3] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76201b5979768500bca362871db66d77cb4c225e

Peter Seiderer (5):
  net: pktgen: replace ENOTSUPP with EOPNOTSUPP
  net: pktgen: enable 'param=value' parsing
  net: pktgen: fix access outside of user given buffer in
    pktgen_thread_write()
  net: pktgen: fix access outside of user given buffer in
    pktgen_if_write()
  selftest: net: add proc_net_pktgen

 net/core/pktgen.c                             | 210 ++++---
 tools/testing/selftests/net/Makefile          |   1 +
 tools/testing/selftests/net/proc_net_pktgen.c | 575 ++++++++++++++++++
 3 files changed, 712 insertions(+), 74 deletions(-)
 create mode 100644 tools/testing/selftests/net/proc_net_pktgen.c