RDX: 0000000020000040 RSI: ffffffffffffffb2 RDI: 0000000000000003 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa8f85636d4 R13: 00000000004bf139 R14: 00000000004d0ac8 R15: 0000000000000005 ================================================================== BUG: KASAN: use-after-free in drm_gem_object_release+0xf1/0x110 drivers/gpu/drm/drm_gem.c:849 Read of size 8 at addr ffff8880905ed890 by task syz-executor.3/20595 CPU: 1 PID: 20595 Comm: syz-executor.3 Not tainted 5.0.0+ #18 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 drm_gem_object_release+0xf1/0x110 drivers/gpu/drm/drm_gem.c:849 __vgem_gem_destroy drivers/gpu/drm/vgem/vgem_drv.c:175 [inline] vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:199 [inline] vgem_gem_dumb_create+0x205/0x260 drivers/gpu/drm/vgem/vgem_drv.c:214 drm_mode_create_dumb+0x288/0x310 drivers/gpu/drm/drm_dumb_buffers.c:92 drm_mode_create_dumb_ioctl+0x26/0x30 drivers/gpu/drm/drm_dumb_buffers.c:98 drm_ioctl_kernel+0x23e/0x2e0 drivers/gpu/drm/drm_ioctl.c:770 drm_ioctl+0x545/0xa50 drivers/gpu/drm/drm_ioctl.c:870 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457f29 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa8f8562c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa8f8562c90 RCX: 0000000000457f29 RDX: 0000000020000040 RSI: ffffffffffffffb2 RDI: 0000000000000003 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa8f85636d4 R13: 00000000004bf139 R14: 00000000004d0ac8 R15: 0000000000000005 Allocated by task 20595: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_kmalloc mm/kasan/common.c:497 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:511 kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3621 kmalloc include/linux/slab.h:545 [inline] kzalloc include/linux/slab.h:740 [inline] __vgem_gem_create+0x49/0x100 drivers/gpu/drm/vgem/vgem_drv.c:158 vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:187 [inline] vgem_gem_dumb_create+0xd7/0x260 drivers/gpu/drm/vgem/vgem_drv.c:214 drm_mode_create_dumb+0x288/0x310 drivers/gpu/drm/drm_dumb_buffers.c:92 drm_mode_create_dumb_ioctl+0x26/0x30 drivers/gpu/drm/drm_dumb_buffers.c:98 drm_ioctl_kernel+0x23e/0x2e0 drivers/gpu/drm/drm_ioctl.c:770 drm_ioctl+0x545/0xa50 drivers/gpu/drm/drm_ioctl.c:870 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 20595: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459 kasan_slab_free+0xe/0x10 mm/kasan/common.c:467 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3821 vgem_gem_free_object+0xbe/0xe0 drivers/gpu/drm/vgem/vgem_drv.c:61 drm_gem_object_free+0x108/0x260 drivers/gpu/drm/drm_gem.c:877 kref_put include/linux/kref.h:67 [inline] drm_gem_object_put_unlocked drivers/gpu/drm/drm_gem.c:911 [inline] drm_gem_object_put_unlocked+0x129/0x170 drivers/gpu/drm/drm_gem.c:896 vgem_gem_create drivers/gpu/drm/vgem/vgem_drv.c:192 [inline] vgem_gem_dumb_create+0x115/0x260 drivers/gpu/drm/vgem/vgem_drv.c:214 drm_mode_create_dumb+0x288/0x310 drivers/gpu/drm/drm_dumb_buffers.c:92 drm_mode_create_dumb_ioctl+0x26/0x30 drivers/gpu/drm/drm_dumb_buffers.c:98 drm_ioctl_kernel+0x23e/0x2e0 drivers/gpu/drm/drm_ioctl.c:770 drm_ioctl+0x545/0xa50 drivers/gpu/drm/drm_ioctl.c:870 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880905ed780 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 272 bytes inside of 512-byte region [ffff8880905ed780, ffff8880905ed980) The buggy address belongs to the page: page:ffffea0002417b40 count:1 mapcount:0 mapping:ffff88812c3f0940 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea000248aac8 ffffea00021a5508 ffff88812c3f0940 raw: 0000000000000000 ffff8880905ed000 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880905ed780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880905ed800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880905ed880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880905ed900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880905ed980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================