batman_adv: batadv0: Interface activated: batadv_slave_1 IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready Bluetooth: hci0 command 0x0409 tx timeout ================================================================== BUG: KASAN: use-after-free in drm_getunique+0x1b4/0x250 drivers/gpu/drm/drm_ioctl.c:118 Read of size 4 at addr ffff8880af695818 by task syz-executor.0/8538 CPU: 1 PID: 8538 Comm: syz-executor.0 Not tainted 4.14.212-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351 kasan_report mm/kasan/report.c:409 [inline] __asan_report_load4_noabort+0x68/0x70 mm/kasan/report.c:429 drm_getunique+0x1b4/0x250 drivers/gpu/drm/drm_ioctl.c:118 drm_ioctl_kernel+0x14c/0x200 drivers/gpu/drm/drm_ioctl.c:736 drm_ioctl+0x419/0x870 drivers/gpu/drm/drm_ioctl.c:836 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45e159 RSP: 002b:00007fdd9f7dfc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e159 RDX: 0000000020000180 RSI: 00000000c0145401 RDI: 0000000000000003 RBP: 000000000119c068 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034 R13: 00007fff4256ec3f R14: 00007fdd9f7e09c0 R15: 000000000119c034 Allocated by task 8536: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x131/0x3d0 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] drm_master_create drivers/gpu/drm/drm_auth.c:100 [inline] drm_new_set_master+0x11a/0x5e0 drivers/gpu/drm/drm_auth.c:138 drm_master_open+0xee/0x120 drivers/gpu/drm/drm_auth.c:236 drm_open_helper drivers/gpu/drm/drm_file.c:251 [inline] drm_open+0x873/0x1010 drivers/gpu/drm/drm_file.c:155 drm_stub_open+0x27b/0x400 drivers/gpu/drm/drm_drv.c:944 chrdev_open+0x23c/0x6d0 fs/char_dev.c:423 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0x628/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 8536: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xc9/0x250 mm/slab.c:3815 drm_master_destroy drivers/gpu/drm/drm_auth.c:322 [inline] kref_put include/linux/kref.h:70 [inline] drm_master_put+0x134/0x180 drivers/gpu/drm/drm_auth.c:333 drm_new_set_master+0x3b1/0x5e0 drivers/gpu/drm/drm_auth.c:157 drm_setmaster_ioctl+0x222/0x2c0 drivers/gpu/drm/drm_auth.c:190 drm_ioctl_kernel+0x14c/0x200 drivers/gpu/drm/drm_ioctl.c:736 drm_ioctl+0x419/0x870 drivers/gpu/drm/drm_ioctl.c:836 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff8880af695800 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 24 bytes inside of 256-byte region [ffff8880af695800, ffff8880af695900) The buggy address belongs to the page: page:ffffea0002bda540 count:1 mapcount:0 mapping:ffff8880af695080 index:0xffff8880af695940 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffff8880af695080 ffff8880af695940 000000010000000a raw: ffffea0002bda160 ffffea0002ca30e0 ffff88813fe807c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880af695700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880af695780: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880af695800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880af695880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880af695900: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ==================================================================