Hello Artur Molchanov,
The patch c09f56b8f68d: "net/sunrpc: Fix return value for sysctl
sunrpc.transports" from Oct 12, 2020, leads to the following static
checker warning:
net/sunrpc/sysctl.c:75 proc_do_xprt()
warn: unsigned '*lenp' is never less than zero.
net/sunrpc/sysctl.c
62 static int proc_do_xprt(struct ctl_table *table, int write,
63 void *buffer, size_t *lenp, loff_t *ppos)
64 {
65 char tmpbuf[256];
66 size_t len;
67
68 if ((*ppos && !write) || !*lenp) {
^^^^^^^
It's weird that we don't just return -EINVAL for writes or something.
69 *lenp = 0;
70 return 0;
71 }
72 len = svc_print_xprts(tmpbuf, sizeof(tmpbuf));
73 *lenp = memory_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
74
75 if (*lenp < 0) {
"*lenp" is unsigned so it can't be less than zero. memory_read_from_buffer()
only returns an error if ppos is negative but that's impossible because
this is a proc file so negatives are prevented in rw_verify_area().
In other words this bug can't affect runtime.
76 *lenp = 0;
77 return -EINVAL;
78 }
79 return 0;
80 }
regards,
dan carpenter
