Description: configfs: fix a use-after-free in __configfs_open_file
References:
 https://source.android.com/security/bulletin/pixel/2021-12-01
Notes:
Bugs:
upstream: released (5.12-rc3) [14fbbc8297728e880070f7b077b3301a8c698ef9]
5.10-upstream-stable: released (5.10.24) [109720342efd6ace3d2e8f34a25ea65036bb1d3b]
4.19-upstream-stable: released (4.19.181) [9123463620132ada85caf5dc664b168f480b0cc4]
4.9-upstream-stable: released (4.9.262) [6f5c47f0faed69f2e78e733fb18261854979e79f]
sid: released (5.10.24-1)
5.10-bullseye-security: N/A "Fixed before branching point"
4.19-buster-security: released (4.19.181-1)
4.9-stretch-security: released (4.9.272-1)