[PATCH 4.9 004/145] cfg80211: check dev_set_name() return value

From: Greg Kroah-Hartman
Date: Fri Feb 23 2018 - 15:07:19 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Johannes Berg <johannes.berg@xxxxxxxxx>

commit 59b179b48ce2a6076448a44531242ac2b3f6cef2 upstream.

syzbot reported a warning from rfkill_alloc(), and after a while
I think that the reason is that it was doing fault injection and
the dev_set_name() failed, leaving the name NULL, and we didn't
check the return value and got to rfkill_alloc() with a NULL name.
Since we really don't want a NULL name, we ought to check the
return value.

Fixes: fb28ad35906a ("net: struct device - replace bus_id with dev_name(), dev_set_name()")
Reported-by: syzbot+1ddfb3357e1d7bb5b5d3@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/wireless/core.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -421,6 +421,8 @@ struct wiphy *wiphy_new_nm(const struct
if (rv)
goto use_default_name;
} else {
+ int rv;
+
use_default_name:
/* NOTE: This is *probably* safe w/out holding rtnl because of
* the restrictions on phy names. Probably this call could
@@ -428,7 +430,11 @@ use_default_name:
* phyX. But, might should add some locking and check return
* value, and use a different name if this one exists?
*/
- dev_set_name(&rdev->wiphy.dev, PHY_NAME "%d", rdev->wiphy_idx);
+ rv = dev_set_name(&rdev->wiphy.dev, PHY_NAME "%d", rdev->wiphy_idx);
+ if (rv < 0) {
+ kfree(rdev);
+ return NULL;
+ }
}

INIT_LIST_HEAD(&rdev->wiphy.wdev_list);