From: Johannes Berg <johannes.berg@xxxxxxxxx>
commit 0bbab5f0301587cad4e923ccc49bb910db86162c upstream.
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@xxxxxxxxxxxxxxx
Fixes: d82574a8e5a4 ("cfg80211: no need to check return value of debugfs_create functions")
Reported-by: syzbot+fd5332e429401bf42d18@xxxxxxxxxxxxxxxxxxxxxxxxx
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200525113816.fc4da3ec3d4b.Ica63a110679819eaa9fb3bc1b7437d96b1fd187d@changeid
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/wireless/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -142,7 +142,7 @@ int cfg80211_dev_rename(struct cfg80211_
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);
