From 6ccbb613b42a1f1ba7bfd547a148f644a902a25c Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 8 May 2026 17:23:39 +0100 Subject: [PATCH] arm_mpam: Check whether the config array is allocated before destroying it __destroy_component_cfg() is called to free the configuration array. It uses the embedded 'garbage' structure, which means the array has to be allocated. If __destroy_component_cfg() is called from mpam_disable() before the configuration was ever allocated, then a NULL pointer is dereferenced. Check for this case and return early if the configuration is not allocated. __destroy_component_cfg() also frees the mbwu_state as this is allocated by __allocate_component_cfg(). As the mbwu_state is allocated after comp->cfg is set, and is also under mpam_list_lock, only the first pointer needs checking. Fixes: 3bd04fe7d807 ("arm_mpam: Extend reset logic to allow devices to be reset any time") Cc: Signed-off-by: James Morse Reviewed-by: Ben Horgan Signed-off-by: Catalin Marinas --- drivers/resctrl/mpam_devices.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 5c48812d8573..988fc291241d 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -2581,6 +2581,9 @@ static void __destroy_component_cfg(struct mpam_component *comp) lockdep_assert_held(&mpam_list_lock); + if (!comp->cfg) + return; + add_to_garbage(comp->cfg); list_for_each_entry(vmsc, &comp->vmsc, comp_list) { msc = vmsc->msc;