================================================================== BUG: KASAN: slab-use-after-free in drm_gem_object_release_handle+0x4b/0x1e0 drivers/gpu/drm/drm_gem.c:374 Read of size 8 at addr ffff888047f22278 by task syz.5.2051/12646 CPU: 0 UID: 0 PID: 12646 Comm: syz.5.2051 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 drm_gem_object_release_handle+0x4b/0x1e0 drivers/gpu/drm/drm_gem.c:374 idr_for_each+0x1c6/0x2a0 lib/idr.c:210 drm_gem_release+0x28/0x40 drivers/gpu/drm/drm_gem.c:1106 drm_file_free+0x729/0xa00 drivers/gpu/drm/drm_file.c:261 drm_close_helper drivers/gpu/drm/drm_file.c:290 [inline] drm_release+0x2de/0x3f0 drivers/gpu/drm/drm_file.c:438 __fput+0x44f/0xa60 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9affb9cdd9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9afff3fba8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f9affe17da0 RCX: 00007f9affb9cdd9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f9affe17da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007f9affe17cb0 R11: 0000000000000246 R12: 0000000000072f1e R13: 00007f9affe1609c R14: 0000000000072da4 R15: 00007f9affe16090 Allocated by task 12648: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5419 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] __drm_gem_shmem_create+0xc4/0x2e0 drivers/gpu/drm/drm_gem_shmem_helper.c:130 drm_gem_shmem_create drivers/gpu/drm/drm_gem_shmem_helper.c:157 [inline] drm_gem_shmem_create_with_handle drivers/gpu/drm/drm_gem_shmem_helper.c:464 [inline] drm_gem_shmem_dumb_create+0x72/0x120 drivers/gpu/drm/drm_gem_shmem_helper.c:553 drm_mode_create_dumb drivers/gpu/drm/drm_dumb_buffers.c:227 [inline] drm_mode_create_dumb_ioctl+0x2bd/0x340 drivers/gpu/drm/drm_dumb_buffers.c:236 drm_ioctl_kernel+0x2df/0x3b0 drivers/gpu/drm/drm_ioctl.c:804 drm_ioctl+0x6ba/0xb80 drivers/gpu/drm/drm_ioctl.c:901 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 12650: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6250 [inline] kfree+0x1c5/0x640 mm/slub.c:6565 drm_gem_object_release_handle+0xc2/0x1e0 drivers/gpu/drm/drm_gem.c:385 drm_gem_handle_delete+0x7b/0xb0 drivers/gpu/drm/drm_gem.c:413 drm_ioctl_kernel+0x2df/0x3b0 drivers/gpu/drm/drm_ioctl.c:804 drm_ioctl+0x6ba/0xb80 drivers/gpu/drm/drm_ioctl.c:901 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888047f22000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 632 bytes inside of freed 1024-byte region [ffff888047f22000, ffff888047f22400) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888047f24800 pfn:0x47f20 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88813fe1adc0 ffff88813fe19888 ffffea0001e8c810 raw: ffff888047f24800 000000080010000d 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88813fe1adc0 ffff88813fe19888 ffffea0001e8c810 head: ffff888047f24800 000000080010000d 00000000f5000000 0000000000000000 head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7781, tgid 7775 (syz.1.615), ts 199255291556, free_ts 199016559729 create_dummy_stack mm/page_owner.c:103 [inline] register_dummy_stack+0x98/0x100 mm/page_owner.c:109 init_page_owner+0x2e/0x5f0 mm/page_owner.c:127 invoke_init_callbacks mm/page_ext.c:152 [inline] page_ext_init+0x500/0x540 mm/page_ext.c:490 mm_core_init+0x97/0xb0 mm/mm_init.c:2738 page last free pid 7801 tgid 7798 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943 __slab_free+0x274/0x2c0 mm/slub.c:5612 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] __kmalloc_cache_noprof+0x2ba/0x660 mm/slub.c:5414 kmalloc_noprof include/linux/slab.h:950 [inline] sched_core_alloc_cookie+0x41/0xa0 kernel/sched/core_sched.c:15 sched_core_share_pid+0x31a/0x7a0 kernel/sched/core_sched.c:187 __do_sys_prctl kernel/sys.c:2808 [inline] __se_sys_prctl+0x89b/0x1980 kernel/sys.c:2534 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888047f22100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888047f22180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888047f22200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888047f22280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888047f22300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================