On Mon, Dec 18, 2017 at 11:02:20PM -0200, Thiago Rafael Becker wrote:
In testing, we found that nfsd threads may call set_groups in parallel for the same entry cached in auth.unix.gid, racing in the call of groups_sort, corrupting the groups for that entry and leading to permission denials for the client.
This patch:
- Make groups_sort globally visible.
- Move the call to groups_sort to the modifiers of group_info
- Remove the call to groups_sort from set_groups
Link: http://lkml.kernel.org/r/20171211151420.18655-1-thiago.becker@gmail.com (backported from bdcf0a423ea1c40bbb40e7ee483b50fc8aa3d758) Signed-off-by: Thiago Rafael Becker thiago.becker@gmail.com Reviewed-by: Matthew Wilcox mawilcox@microsoft.com Reviewed-by: NeilBrown neilb@suse.com Acked-by: "J. Bruce Fields" bfields@fieldses.org Cc: Al Viro viro@zeniv.linux.org.uk Cc: Martin Schwidefsky schwidefsky@de.ibm.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org
Any hint as to what kernel tree(s) this backport is for?
thanks,
greg k-h