James J. Lippard <[email protected]> wrote:
> I have a host which uses sensorsd which periodically stops running, which
> prompted me to dig into the cause, it's one or both of these two issues:
>
> (1) memory leak on configuration reload, lines 753-758:
>
> if (cgetstr(buf, "command", &ebuf) < 0)
> ebuf = NULL;
> if (ebuf != NULL) {
> p->command = ebuf;
> ebuf = NULL;
> }
>
> cgetstr allocates a new ebuf and the previous pointer is overwritten
> without freeing the old one.
>
> Fix: insert free(p->command) before p->command = ebuf:
>
> if (cgetstr(buf, "command", &ebuf) < 0)
> ebuf = NULL;
> if (ebuf != NULL) {
> free(p->command);
> p->command = ebuf;
> ebuf = NULL;
> }
>
> (2) unnecessary exit in check_sdlim lines 367-368 for individual
> sensor failure that is handled differently from the same code in
> create_sdlim; sensorsd shouldn't be aborting because of a sysctl
> failure on one sensor.
>
> if (sysctl(mib, 5, &sensor, &len, NULL, 0) == -1)
> err(1, "sysctl");
>
> vs. create_sdlim, lines 240-243:
>
> if (sysctl(mib, 5, &sensor, &slen, NULL, 0) == -1) {
> if (errno != ENOENT)
> warn("sysctl");
> continue;
> }
>
> Fix: make check_sdlim code equivalent to create_sdlim:
>
> if (sysctl(mib, 5, &sensor, &len, NULL, 0) == -1) {
> if (errno != ENOENT)
> warn("sysctl");
> continue;
> }
Like this.
Index: sensorsd.c
===================================================================
RCS file: /cvs/src/usr.sbin/sensorsd/sensorsd.c,v
diff -u -p -u -r1.69 sensorsd.c
--- sensorsd.c 8 Mar 2023 04:43:15 -0000 1.69
+++ sensorsd.c 11 Apr 2026 17:33:22 -0000
@@ -363,8 +363,11 @@ check_sdlim(struct sdlim_t *sdlim, time_
mib[3] = limit->type;
mib[4] = limit->numt;
- if (sysctl(mib, 5, &sensor, &len, NULL, 0) == -1)
- err(1, "sysctl");
+ if (sysctl(mib, 5, &sensor, &len, NULL, 0) == -1) {
+ if (errno != ENOENT)
+ warn("sysctl");
+ continue;
+ }
if (!(limit->flags & SENSORSD_L_ISTATUS)) {
enum sensor_status newastatus = sensor.status;
@@ -753,6 +756,7 @@ parse_config_sdlim(struct sdlim_t *sdlim
if (cgetstr(buf, "command", &ebuf) < 0)
ebuf = NULL;
if (ebuf != NULL) {
+ free(p->command);
p->command = ebuf;
ebuf = NULL;
}
