On Mon, May 25, 2020 at 11:38:17AM +0200, Johannes Berg wrote:
From: Johannes Berg johannes.berg@intel.com
Removing the "if (IS_ERR(dir)) dir = NULL;" check only works if we adjust the remaining code to not rely on it being NULL. Check IS_ERR_OR_NULL() before attempting to dereference it.
I'm not actually entirely sure this fixes the syzbot crash as the kernel config indicates that they do have DEBUG_FS in the kernel, but this is what I found when looking there.
Cc: stable@vger.kernel.org Fixes: d82574a8e5a4 ("cfg80211: no need to check return value of debugfs_create functions") Reported-by: syzbot+fd5332e429401bf42d18@syzkaller.appspotmail.com Signed-off-by: Johannes Berg johannes.berg@intel.com
net/wireless/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/wireless/core.c b/net/wireless/core.c index 341402b4f178..ce024440fa51 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -142,7 +142,7 @@ int cfg80211_dev_rename(struct cfg80211_registered_device *rdev, if (result) return result;
- if (rdev->wiphy.debugfsdir)
- if (!IS_ERR_OR_NULL(rdev->wiphy.debugfsdir)) debugfs_rename(rdev->wiphy.debugfsdir->d_parent, rdev->wiphy.debugfsdir, rdev->wiphy.debugfsdir->d_parent, newname);
I missed that d_parent was being accessed, sorry about that. This looks good to me:
Reviewed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org