[PATCH net-next v4 06/17] net: pktgen: fix ctrl interface command parsing

Peter Seiderer
2025-02-05T13:12:06Z

Enable command writing without trailing '\n':

- the good case

$ echo "reset" > /proc/net/pktgen/pgctrl

- the bad case (before the patch)

$ echo -n "reset" > /proc/net/pktgen/pgctrl
-bash: echo: write error: Invalid argument

- with patch applied

$ echo -n "reset" > /proc/net/pktgen/pgctrl

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Reviewed-by: Simon Horman <horms@kernel.org>
---
Changes v3 -> v4
- add rev-by Simon Horman

Changes v2 -> v3:
- new patch
---
net/core/pktgen.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index c8a5b4d17407..f6e35ba035c7 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -517,21 +517,23 @@ static ssize_t pgctrl_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char data[128];
+ size_t max;
struct pktgen_net *pn = net_generic(current->nsproxy->net_ns, pg_net_id);

if (!capable(CAP_NET_ADMIN))
return -EPERM;

- if (count == 0)
+ if (count < 1)
return -EINVAL;

- if (count > sizeof(data))
- count = sizeof(data);
-
- if (copy_from_user(data, buf, count))
+ max = min(count, sizeof(data) - 1);
+ if (copy_from_user(data, buf, max))
return -EFAULT;

- data[count - 1] = 0; /* Strip trailing '\n' and terminate string */
+ if (data[max - 1] == '\n')
+ data[max - 1] = 0; /* strip trailing '\n', terminate string */
+ else
+ data[max] = 0; /* terminate string */

if (!strcmp(data, "stop"))
pktgen_stop_all_threads(pn);
--
2.48.1