RDX: 0000000000000000 RSI: 0000000000003000 RDI: 0000000020ffc000 RBP: 00007ffdf4ae0920 R08: 0000000000000003 R09: 0000000100000000 R10: 0000000000000012 R11: 0000000000000246 R12: 0000000000000004 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ================================================================== BUG: KASAN: use-after-free in drm_gem_object_release_handle+0xd1/0xf0 drivers/gpu/drm/drm_gem.c:252 Read of size 8 at addr ffff88801d68fa28 by task syz-executor655/5870 CPU: 0 PID: 5870 Comm: syz-executor655 Not tainted 5.14.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x57/0x7d lib/dump_stack.c:105 print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:436 drm_gem_object_release_handle+0xd1/0xf0 drivers/gpu/drm/drm_gem.c:252 idr_for_each+0xf5/0x1d0 lib/idr.c:208 drm_gem_release+0x17/0x20 drivers/gpu/drm/drm_gem.c:930 drm_file_free.part.0+0x7a1/0xb60 drivers/gpu/drm/drm_file.c:281 drm_release+0x1bb/0x4b0 drivers/gpu/drm/drm_file.c:495 __fput+0x209/0x870 fs/file_table.c:280 task_work_run+0xc0/0x160 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0x9fe/0x24e0 kernel/exit.c:825 do_group_exit+0xe7/0x290 kernel/exit.c:922 __do_sys_exit_group kernel/exit.c:933 [inline] __se_sys_exit_group kernel/exit.c:931 [inline] __x64_sys_exit_group+0x35/0x40 kernel/exit.c:931 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f5cbd9759e9 Code: Unable to access opcode bytes at RIP 0x7f5cbd9759bf. RSP: 002b:00007ffdf4ae08f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f5cbd9e93f0 RCX: 00007f5cbd9759e9 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000100000000 R10: 0000000000000012 R11: 0000000000000246 R12: 00007f5cbd9e93f0 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 Allocated by task 5870: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0x9b/0xd0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] vgem_gem_create_object+0x35/0x90 drivers/gpu/drm/vgem/vgem_drv.c:98 __drm_gem_shmem_create+0x72/0x3e0 drivers/gpu/drm/drm_gem_shmem_helper.c:52 drm_gem_shmem_create drivers/gpu/drm/drm_gem_shmem_helper.c:114 [inline] drm_gem_shmem_create_with_handle+0x19/0x90 drivers/gpu/drm/drm_gem_shmem_helper.c:420 drm_gem_shmem_dumb_create+0x131/0x270 drivers/gpu/drm/drm_gem_shmem_helper.c:536 drm_ioctl_kernel+0x1c9/0x260 drivers/gpu/drm/drm_ioctl.c:795 drm_ioctl+0x444/0x8f0 drivers/gpu/drm/drm_ioctl.c:898 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl fs/ioctl.c:1055 [inline] __x64_sys_ioctl+0x11f/0x190 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 5870: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xfb/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1625 [inline] slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1650 slab_free mm/slub.c:3210 [inline] kfree+0xeb/0x650 mm/slub.c:4262 kref_put include/linux/kref.h:65 [inline] __drm_gem_object_put include/drm/drm_gem.h:371 [inline] drm_gem_object_put include/drm/drm_gem.h:384 [inline] drm_gem_mmap+0x3be/0x4e0 drivers/gpu/drm/drm_gem.c:1132 call_mmap include/linux/fs.h:2119 [inline] mmap_region+0xa3c/0x14e0 mm/mmap.c:1808 do_mmap+0x5d3/0xfc0 mm/mmap.c:1584 vm_mmap_pgoff+0x163/0x210 mm/util.c:519 ksys_mmap_pgoff+0x3be/0x5f0 mm/mmap.c:1635 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff88801d68f800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 552 bytes inside of 1024-byte region [ffff88801d68f800, ffff88801d68fc00) The buggy address belongs to the page: page:ffffea000075a200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1d688 head:ffffea000075a200 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff88800fc41dc0 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, ts 5555902984, free_ts 0 prep_new_page mm/page_alloc.c:2436 [inline] get_page_from_freelist+0xa6f/0x2f50 mm/page_alloc.c:4169 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5391 alloc_page_interleave+0xf/0x1c0 mm/mempolicy.c:2119 alloc_slab_page mm/slub.c:1688 [inline] allocate_slab+0x32e/0x4b0 mm/slub.c:1828 new_slab mm/slub.c:1891 [inline] new_slab_objects mm/slub.c:2637 [inline] ___slab_alloc+0x4ba/0x820 mm/slub.c:2800 __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2840 slab_alloc_node mm/slub.c:2922 [inline] __kmalloc_node_track_caller+0x2e3/0x360 mm/slub.c:4648 alloc_dr drivers/gpu/drm/drm_managed.c:95 [inline] drmm_kmalloc+0x7e/0x1f0 drivers/gpu/drm/drm_managed.c:192 drmm_kzalloc include/drm/drm_managed.h:61 [inline] __drmm_universal_plane_alloc+0x141/0x260 drivers/gpu/drm/drm_plane.c:430 vkms_plane_init+0x64/0xc0 drivers/gpu/drm/vkms/vkms_plane.c:189 vkms_output_init+0x27/0x440 drivers/gpu/drm/vkms/vkms_output.c:46 vkms_modeset_init drivers/gpu/drm/vkms/vkms_drv.c:158 [inline] vkms_create drivers/gpu/drm/vkms/vkms_drv.c:200 [inline] vkms_init+0x4bb/0x54c drivers/gpu/drm/vkms/vkms_drv.c:233 do_one_initcall+0xbe/0x440 init/main.c:1282 do_initcall_level init/main.c:1355 [inline] do_initcalls init/main.c:1371 [inline] do_basic_setup init/main.c:1391 [inline] kernel_init_freeable+0x5b2/0x60c init/main.c:1593 kernel_init+0x14/0x120 init/main.c:1485 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 page_owner free stack trace missing Memory state around the buggy address: ffff88801d68f900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801d68f980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801d68fa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801d68fa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801d68fb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================