nfsd: auth: Fix gid sorting when rootsquash enabled
commit 1995266727fa8143897e89b55f5d3c79aa828420 upstream.
Commit bdcf0a423ea1 ("kernel: make groups_sort calling a responsibility
group_info allocators") appears to break nfsd rootsquash in a pretty
major way.
It adds a call to groups_sort() inside the loop that copies/squashes
gids, which means the valid gids are sorted along with the following
garbage. The net result is that the highest numbered valid gids are
replaced with any lower-valued garbage gids, possibly including 0.
We should sort only once, after filling in all the gids.
BUG=b:74376716
TEST=lakitu-release tryjob.
Change-Id: I0dff27fdfe43bfbfcaf1743469a32227faad5a8b
Fixes: bdcf0a423ea1 ("kernel: make groups_sort calling a responsibility ...")
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Wolfgang Walter <linux@stwm.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pradeep Sawlani <sawlani@google.com>
Reviewed-on: https://chromium-review.googlesource.com/959353
Reviewed-by: Daniel Wang <wonderfly@google.com>
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
1 file changed
