From 0bbab5f0301587cad4e923ccc49bb910db86162c Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Mon, 25 May 2020 11:38:17 +0200 Subject: [PATCH] cfg80211: fix debugfs rename crash 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 Reviewed-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20200525113816.fc4da3ec3d4b.Ica63a110679819eaa9fb3bc1b7437d96b1fd187d@changeid Signed-off-by: Johannes Berg --- 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 341402b4f17880..ce024440fa51f0 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);