On Sat, 2021-01-23 at 16:19 +0800, lixiaokeng wrote:
> When I test the 0.8.5 code with iscsi login/out, multipathd command
> and multipath command concurrently, there is a multipathd coredump.
> The stack is shown:
>
> uxlsnrloop
> ->cli_list_devices
> ->show_devices
> ->snprint_devices
> ->find_path_by_dev
>
> The reason is that devname is NULL in snprint_devices, then it will
> be dereference. Here we check dev in find_path_by_dev.
> ---
> libmultipath/structs.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/libmultipath/structs.c b/libmultipath/structs.c
> index 464596f..a3f27fd 100644
> --- a/libmultipath/structs.c
> +++ b/libmultipath/structs.c
> @@ -453,12 +453,12 @@ find_mp_by_str (const struct _vector *mpvec,
> const char * str)
> }
>
> struct path *
> -find_path_by_dev (const struct _vector *pathvec, const char * dev)
> +find_path_by_dev (const struct _vector *pathvec, const char *dev)
> {
> int i;
> struct path * pp;
>
> - if (!pathvec)
> + if (!pathvec || !dev)
> return NULL;
>
> vector_foreach_slot (pathvec, pp, i)
Reviewed-by: Martin Wilck <mwilck@xxxxxxx>
However, the actual issue is in snprint_devices():
r = udev_enumerate_scan_devices(enm);
first = udev_enumerate_get_list_entry(enm);
udev_list_entry_foreach(item, first) {
path = udev_list_entry_get_name(item);
u_dev = udev_device_new_from_syspath(udev, path);
devname = udev_device_get_sysname(u_dev);
pp = find_path_by_dev(vecs->pathvec, devname);
if devname was NULL here, it means that the list returned by
udev_enumerate_scan_devices() contains devices that don't exist
(any more), even though the call to udev_enumerate_scan_devices() was
just a few LoC above. It's the kind of thing you don't expect, but you
should expect when you deal with udev :-/
I'll send a patch for that, too.
Martin
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
