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... [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/?i...
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