From: Maciej Patelczyk Date: Mon, 9 Feb 2026 12:34:33 +0000 (+0100) Subject: drm/gpusvm: Fix unbalanced unlock in drm_gpusvm_scan_mm() X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=d287dee565c3c32e1ed76ec1847af46809c29b90;p=thirdparty%2Fkernel%2Flinux.git drm/gpusvm: Fix unbalanced unlock in drm_gpusvm_scan_mm() There is a unbalanced lock/unlock to gpusvm notifier lock: [ 931.045868] ===================================== [ 931.046509] WARNING: bad unlock balance detected! [ 931.047149] 6.19.0-rc6+xe-**************** #9 Tainted: G U [ 931.048150] ------------------------------------- [ 931.048790] kworker/u5:0/51 is trying to release lock (&gpusvm->notifier_lock) at: [ 931.049801] [] drm_gpusvm_scan_mm+0x188/0x460 [drm_gpusvm_helper] [ 931.050802] but there are no more locks to release! [ 931.051463] The drm_gpusvm_notifier_unlock() sits under err_free label and the first jump to err_free is just before calling the drm_gpusvm_notifier_lock() causing unbalanced unlock. Fixes: f1d08a586482 ("drm/gpusvm: Introduce a function to scan the current migration state") Signed-off-by: Maciej Patelczyk Cc: Thomas Hellström Reviewed-by: Matthew Brost Signed-off-by: Matthew Brost Link: https://patch.msgid.link/20260209123433.1271053-1-maciej.patelczyk@intel.com --- diff --git a/drivers/gpu/drm/drm_gpusvm.c b/drivers/gpu/drm/drm_gpusvm.c index 871fcccd128a9..c25f50cad6fe4 100644 --- a/drivers/gpu/drm/drm_gpusvm.c +++ b/drivers/gpu/drm/drm_gpusvm.c @@ -819,7 +819,7 @@ retry: if (!(pfns[i] & HMM_PFN_VALID)) { state = DRM_GPUSVM_SCAN_UNPOPULATED; - goto err_free; + break; } page = hmm_pfn_to_page(pfns[i]); @@ -856,9 +856,9 @@ retry: i += 1ul << drm_gpusvm_hmm_pfn_to_order(pfns[i], i, npages); } -err_free: drm_gpusvm_notifier_unlock(range->gpusvm); +err_free: kvfree(pfns); return state; }