------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 8352 at lib/refcount.c:28 refcount_warn_saturate+0x1a0/0x1c8 lib/refcount.c:28 Modules linked in: CPU: 0 PID: 8352 Comm: syz-executor.5 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : refcount_warn_saturate+0x1a0/0x1c8 lib/refcount.c:28 lr : refcount_warn_saturate+0x1a0/0x1c8 lib/refcount.c:28 sp : ffff8000149bbb50 x29: ffff8000149bbb50 x28: 00000000000000b4 x27: ffff00010b817000 x26: 0000000000000004 x25: 0000000000000000 x24: ffff0001021b7c00 x23: 0000000000000001 x22: ffff00010b817000 x21: 0000000000000000 x20: 0000000000000003 x19: ffff80000d8c8000 x18: 0000000000000141 x17: 0000000000000000 x16: ffff80000db49158 x15: ffff000100c0b500 x14: 0000000000000000 x13: 00000000ffffffff x12: 0000000000040000 x11: 0000000000002a03 x10: ffff800012c26000 x9 : 16288f2ef5049800 x8 : 16288f2ef5049800 x7 : ffff800008161d1c x6 : 0000000000000000 x5 : 0000000000000080 x4 : 0000000000000001 x3 : 0000000000000000 x2 : ffff000100c0b500 x1 : 0000000100000000 x0 : 0000000000000026 Call trace: refcount_warn_saturate+0x1a0/0x1c8 lib/refcount.c:28 __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] kref_put include/linux/kref.h:64 [inline] __drm_gem_object_put include/drm/drm_gem.h:381 [inline] drm_gem_object_put include/drm/drm_gem.h:394 [inline] drm_gem_object_handle_put_unlocked+0x178/0x1a0 drivers/gpu/drm/drm_gem.c:225 drm_gem_object_release_handle drivers/gpu/drm/drm_gem.c:244 [inline] drm_gem_handle_delete+0xb4/0xf0 drivers/gpu/drm/drm_gem.c:272 drm_gem_dumb_destroy+0x28/0x38 drivers/gpu/drm/drm_gem.c:328 drm_mode_destroy_dumb drivers/gpu/drm/drm_dumb_buffers.c:145 [inline] drm_mode_destroy_dumb_ioctl+0x74/0x88 drivers/gpu/drm/drm_dumb_buffers.c:153 drm_ioctl_kernel+0x19c/0x250 drivers/gpu/drm/drm_ioctl.c:782 drm_ioctl+0x3a0/0x5bc drivers/gpu/drm/drm_ioctl.c:885 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 irq event stamp: 84 hardirqs last enabled at (83): [] raw_spin_rq_unlock_irq kernel/sched/sched.h:1367 [inline] hardirqs last enabled at (83): [] finish_lock_switch+0x94/0xe8 kernel/sched/core.c:4942 hardirqs last disabled at (84): [] el1_dbg+0x24/0x5c arch/arm64/kernel/entry-common.c:404 softirqs last enabled at (8): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32 softirqs last disabled at (6): [] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19 ---[ end trace 0000000000000000 ]---