[PATCH net-next v4 00/17] Some pktgen fixes/improvments

Peter Seiderer
2025-02-05T13:12:03Z

hile 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 some minor findings) and add a simple
proc_net_pktgen selftest...

Regards,
Peter

Changes v3 -> v4:
- add rev-by Simon Horman
- new patch 'net: pktgen: use defines for the various dec/hex number parsing
digits lengths' (suggested by Simon Horman)
- replace C99 comment (suggested by Paolo Abeni)
- drop available characters check in strn_len() (suggested by Paolo Abeni)
- factored out patch 'net: pktgen: align some variable declarations to the
most common pattern' (suggested by Paolo Abeni)
- factored out patch 'net: pktgen: remove extra tmp variable (re-use len
instead)' (suggested by Paolo Abeni)
- factored out patch 'net: pktgen: remove some superfluous variable
initializing' (suggested by Paolo Abeni)
- factored out patch 'net: pktgen: fix mpls maximum labels list parsing'
(suggested by Paolo Abeni)
- factored out 'net: pktgen: hex32_arg/num_arg error out in case no
characters are available' (suggested by Paolo Abeni)
- factored out 'net: pktgen: num_arg error out in case no valid character
is parsed' (suggested by Paolo Abeni)

Changes v2 -> v3:
- new patch: 'net: pktgen: fix ctrl interface command parsing'
- new patch: 'net: pktgen: fix mpls reset parsing'
- tools/testing/selftests/net/proc_net_pktgen.c:
- fix typo in change description ('v1 -> v1' and tyop)
- rename some vars to better match usage
add_loopback_0 -> thr_cmd_add_loopback_0
rm_loopback_0 -> thr_cmd_rm_loopback_0
wrong_ctrl_cmd -> wrong_thr_cmd
legacy_ctrl_cmd -> legacy_thr_cmd
ctrl_fd -> thr_fd
- add ctrl interface tests

Changes v1 -> v2:
- new patch: 'net: pktgen: fix hex32_arg parsing for short reads'
- new patch: 'net: pktgen: fix 'rate 0' error handling (return -EINVAL)'
- new patch: 'net: pktgen: fix 'ratep 0' error handling (return -EINVAL)'
- net/core/pktgen.c: additional fix get_imix_entries() and get_labels()
- tools/testing/selftests/net/proc_net_pktgen.c:
- fix tyop not vs. nod (suggested by Jakub Kicinski)
- fix misaligned line (suggested by Jakub Kicinski)
- enable fomerly commented out CONFIG_XFRM dependent test (command spi),
as CONFIG_XFRM is enabled via tools/testing/selftests/net/config
CONFIG_XFRM_INTERFACE/CONFIG_XFRM_USER (suggestex by Jakub Kicinski)
- add CONFIG_NET_PKTGEN=m to tools/testing/selftests/net/config
(suggested by Jakub Kicinski)
- add modprobe pktgen to FIXTURE_SETUP() (suggested by Jakub Kicinski)
- fix some checkpatch warnings (Missing a blank line after declarations)
- shrink line length by re-naming some variables (command -> cmd,
device -> dev)
- add 'rate 0' testcase
- add 'ratep 0' testcase

[1] https://lore.kernel.org/netdev/20241006221221.3744995-1-artem.chernyshev@red-soft.ru/
[2] https://lore.kernel.org/netdev/20250109083039.14004-1-pchelkin@ispras.ru/
[3] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76201b5979768500bca362871db66d77cb4c225e

Peter Seiderer (17):
net: pktgen: replace ENOTSUPP with EOPNOTSUPP
net: pktgen: enable 'param=value' parsing
net: pktgen: fix hex32_arg parsing for short reads
net: pktgen: fix 'rate 0' error handling (return -EINVAL)
net: pktgen: fix 'ratep 0' error handling (return -EINVAL)
net: pktgen: fix ctrl interface command parsing
net: pktgen: fix access outside of user given buffer in
pktgen_thread_write()
net: pktgen: use defines for the various dec/hex number parsing digits
lengths
net: pktgen: align some variable declarations to the most common
pattern
net: pktgen: remove extra tmp variable (re-use len instead)
net: pktgen: remove some superfluous variable initializing
net: pktgen: fix mpls maximum labels list parsing
net: pktgen: fix access outside of user given buffer in
pktgen_if_write()
net: pktgen: hex32_arg/num_arg error out in case no characters are
available
net: pktgen: num_arg error out in case no valid character is parsed
net: pktgen: fix mpls reset parsing
selftest: net: add proc_net_pktgen

net/core/pktgen.c | 268 +++++---
tools/testing/selftests/net/Makefile | 1 +
tools/testing/selftests/net/config | 1 +
tools/testing/selftests/net/proc_net_pktgen.c | 650 ++++++++++++++++++
4 files changed, 828 insertions(+), 92 deletions(-)
create mode 100644 tools/testing/selftests/net/proc_net_pktgen.c

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2.48.1