================================================================== 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 ffff888052b63a78 by task syz.0.3420/24963 CPU: 1 UID: 0 PID: 24963 Comm: syz.0.3420 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:1126 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+0xf3/0x4d0 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: 0033:0x7fadffb9ce59 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:00007fadfff3fba8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fadffe17da0 RCX: 00007fadffb9ce59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fadffe17da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007fadffe17cb0 R11: 0000000000000246 R12: 00000000001b50ed R13: 00007fadffe1609c R14: 00000000001b5087 R15: 00007fadfff3fcb0 Allocated by task 24972: 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 24972: 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 ffff888052b63800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 632 bytes inside of freed 1024-byte region [ffff888052b63800, ffff888052b63c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888052b64800 pfn:0x52b60 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 ffffea0000aff410 ffffea00015a0610 raw: ffff888052b64800 000000080010000f 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88813fe1adc0 ffffea0000aff410 ffffea00015a0610 head: ffff888052b64800 000000080010000f 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 8480, tgid 8477 (syz.2.558), ts 305011906689, free_ts 304539605431 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x339/0x3d0 mm/slub.c:7271 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] __do_kmalloc_node mm/slub.c:5294 [inline] __kmalloc_node_track_caller_noprof+0x572/0x7b0 mm/slub.c:5407 kmalloc_reserve net/core/skbuff.c:635 [inline] __alloc_skb+0x2c1/0x7d0 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1383 [inline] xfrm_alloc_compat+0x1a6/0x16f0 net/xfrm/xfrm_compat.c:348 xfrm_nlmsg_multicast+0xda/0x1f0 net/xfrm/xfrm_user.c:1593 xfrm_send_acquire+0x9c9/0xf20 net/xfrm/xfrm_user.c:3868 km_query+0x11c/0x210 net/xfrm/xfrm_state.c:2782 xfrm_state_find+0x3f9e/0x5e90 net/xfrm/xfrm_state.c:1559 xfrm_tmpl_resolve_one net/xfrm/xfrm_policy.c:2522 [inline] xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:2573 [inline] xfrm_resolve_and_create_bundle+0x81c/0x30a0 net/xfrm/xfrm_policy.c:2871 xfrm_lookup_with_ifid+0x28b/0x1b90 net/xfrm/xfrm_policy.c:3205 xfrm_lookup net/xfrm/xfrm_policy.c:3336 [inline] xfrm_lookup_route+0x3c/0x1c0 net/xfrm/xfrm_policy.c:3347 page last free pid 4995 tgid 4995 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] __do_kmalloc_node mm/slub.c:5294 [inline] __kvmalloc_node_noprof+0x4d7/0x8a0 mm/slub.c:6832 seq_buf_alloc fs/seq_file.c:39 [inline] seq_read_iter+0x202/0xe10 fs/seq_file.c:211 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x582/0xa70 fs/read_write.c:574 ksys_read+0x150/0x270 fs/read_write.c:717 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: ffff888052b63900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888052b63980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888052b63a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888052b63a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888052b63b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================