From b9f089723aee892efc77c349ae47a6b452b293c4 Mon Sep 17 00:00:00 2001 From: Reinette Chatre Date: Mon, 6 Jul 2026 15:46:23 -0700 Subject: [PATCH] fs/resctrl: Fix double-add of pseudo-locked region's RMID to free list A pseudo-locked group's RMID is freed when it is created. On unmount rmdir_all_sub() unconditionally frees all RMID of all groups, resulting in a double-free of the pseudo-locked group's RMID. The consequence of this is that the original free results in the pseudo-locked group's RMID being added to the rmid_free_lru linked list and the second free then attempts to add the same RMID entry to the rmid_free_lru again. Do not double-free a pseudo-locked group's RMID. Fixes: e0bdfe8e36f3 ("x86/intel_rdt: Support creation/removal of pseudo-locked region") Signed-off-by: Reinette Chatre Signed-off-by: Borislav Petkov (AMD) Cc: Link: https://patch.msgid.link/551432dd7e624a862b8e58314c38aaba0afff3e9.1783377598.git.reinette.chatre@intel.com --- fs/resctrl/rdtgroup.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c index ce277f16ea12..cc9966ff6cdf 100644 --- a/fs/resctrl/rdtgroup.c +++ b/fs/resctrl/rdtgroup.c @@ -3084,10 +3084,6 @@ static void rmdir_all_sub(void) if (rdtgrp == &rdtgroup_default) continue; - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || - rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) - rdtgroup_pseudo_lock_remove(rdtgrp); - /* * Give any CPUs back to the default group. We cannot copy * cpu_online_mask because a CPU might have executed the @@ -3098,7 +3094,13 @@ static void rmdir_all_sub(void) rdtgroup_unassign_cntrs(rdtgrp); - free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || + rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { + rdtgroup_pseudo_lock_remove(rdtgrp); + } else { + /* Pseudo-locked group's RMID is freed during setup. */ + free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); + } kernfs_remove(rdtgrp->kn); list_del(&rdtgrp->rdtgroup_list); -- 2.47.3