OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.162' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 38.076117] ================================================================== [ 38.083703] BUG: KASAN: use-after-free in vgem_gem_dumb_create+0x22c/0x240 [ 38.090722] Read of size 8 at addr ffff8880a4c02680 by task syz-executor059/8116 [ 38.098250] [ 38.099884] CPU: 1 PID: 8116 Comm: syz-executor059 Not tainted 4.19.172-syzkaller #0 [ 38.107762] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.117117] Call Trace: [ 38.119805] dump_stack+0x1fc/0x2ef executing program executing program executing program [ 38.123447] print_address_description.cold+0x54/0x219 [ 38.128734] kasan_report_error.cold+0x8a/0x1b9 [ 38.133409] ? vgem_gem_dumb_create+0x22c/0x240 [ 38.138092] __asan_report_load8_noabort+0x88/0x90 [ 38.143033] ? drm_gem_object_put_unlocked+0x40/0x180 [ 38.148230] ? vgem_gem_dumb_create+0x22c/0x240 [ 38.152909] vgem_gem_dumb_create+0x22c/0x240 [ 38.157418] drm_mode_create_dumb+0x27c/0x300 [ 38.161927] drm_ioctl_kernel+0x208/0x2a0 [ 38.166086] ? drm_mode_create_dumb+0x300/0x300 [ 38.170761] ? drm_ioctl_permit+0x210/0x210 executing program executing program executing program executing program executing program [ 38.175090] ? __might_fault+0x192/0x1d0 [ 38.179172] drm_ioctl+0x507/0x9c0 [ 38.182723] ? drm_mode_create_dumb+0x300/0x300 [ 38.187403] ? drm_getstats+0x20/0x20 [ 38.191215] ? __fget+0x356/0x510 [ 38.194685] ? futex_exit_release+0x220/0x220 [ 38.199191] ? drm_getstats+0x20/0x20 [ 38.203004] do_vfs_ioctl+0xcdb/0x12e0 [ 38.206898] ? lock_downgrade+0x720/0x720 [ 38.211044] ? check_preemption_disabled+0x41/0x280 [ 38.216056] ? ioctl_preallocate+0x200/0x200 [ 38.220494] ? __fget+0x356/0x510 [ 38.223945] ? do_dup2+0x450/0x450 [ 38.227484] ? __se_sys_futex+0x298/0x3b0 [ 38.231660] ksys_ioctl+0x9b/0xc0 [ 38.235125] __x64_sys_ioctl+0x6f/0xb0 [ 38.239011] ? lockdep_hardirqs_on+0x3a8/0x5c0 [ 38.243588] do_syscall_64+0xf9/0x620 [ 38.247391] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.252590] RIP: 0033:0x44a579 [ 38.255778] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 [ 38.274676] RSP: 002b:00007fd6aff2e1f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 38.282383] RAX: ffffffffffffffda RBX: 00000000004cb4e8 RCX: 000000000044a579 [ 38.289650] RDX: 00000000200000c0 RSI: 00000000c02064b2 RDI: 0000000000000004 [ 38.296918] RBP: 00000000004cb4e0 R08: 0000000000000000 R09: 0000000000000000 [ 38.304201] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb4ec [ 38.311475] R13: 00007ffde95653df R14: 00007fd6aff2e300 R15: 0000000000022000 [ 38.318751] [ 38.320370] Allocated by task 8116: [ 38.323996] kmem_cache_alloc_trace+0x12f/0x380 [ 38.328663] __vgem_gem_create+0x44/0xf0 [ 38.332716] vgem_gem_dumb_create+0xcf/0x240 [ 38.337118] drm_mode_create_dumb+0x27c/0x300 [ 38.341627] drm_ioctl_kernel+0x208/0x2a0 [ 38.345771] drm_ioctl+0x507/0x9c0 [ 38.349307] do_vfs_ioctl+0xcdb/0x12e0 [ 38.353186] ksys_ioctl+0x9b/0xc0 [ 38.356632] __x64_sys_ioctl+0x6f/0xb0 [ 38.360517] do_syscall_64+0xf9/0x620 [ 38.364310] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.369502] [ 38.371120] Freed by task 8116: [ 38.374392] kfree+0xcc/0x210 [ 38.377489] drm_gem_object_free+0x91/0x1c0 [ 38.381806] drm_gem_object_put_unlocked+0xd1/0x180 [ 38.386905] vgem_gem_dumb_create+0x10c/0x240 [ 38.391414] drm_mode_create_dumb+0x27c/0x300 [ 38.395903] drm_ioctl_kernel+0x208/0x2a0 [ 38.400046] drm_ioctl+0x507/0x9c0 [ 38.403594] do_vfs_ioctl+0xcdb/0x12e0 [ 38.407474] ksys_ioctl+0x9b/0xc0 [ 38.410929] __x64_sys_ioctl+0x6f/0xb0 [ 38.414828] do_syscall_64+0xf9/0x620 [ 38.418627] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.423806] [ 38.425424] The buggy address belongs to the object at ffff8880a4c02580 [ 38.425424] which belongs to the cache kmalloc-512 of size 512 [ 38.438077] The buggy address is located 256 bytes inside of [ 38.438077] 512-byte region [ffff8880a4c02580, ffff8880a4c02780) [ 38.449940] The buggy address belongs to the page: [ 38.454883] page:ffffea0002930080 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0 [ 38.463019] flags: 0xfff00000000100(slab) [ 38.467164] raw: 00fff00000000100 ffffea00029301c8 ffffea000294dc48 ffff88813bff0940 [ 38.475047] raw: 0000000000000000 ffff8880a4c02080 0000000100000006 0000000000000000 [ 38.482914] page dumped because: kasan: bad access detected [ 38.488613] [ 38.490233] Memory state around the buggy address: [ 38.495154] ffff8880a4c02580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.502507] ffff8880a4c02600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.509857] >ffff8880a4c02680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.517200] ^ [ 38.520559] ffff8880a4c02700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb executing program executing program executing program executing program executing program executing program [ 38.527911] ffff8880a4c02780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 38.535258] ================================================================== [ 38.542611] Disabling lock debugging due to kernel taint [ 38.565868] Kernel panic - not syncing: panic_on_warn set ... [ 38.565868] executing program executing program executing program executing program executing program [ 38.573269] CPU: 1 PID: 8116 Comm: syz-executor059 Tainted: G B 4.19.172-syzkaller #0 [ 38.582536] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.591883] Call Trace: [ 38.594478] dump_stack+0x1fc/0x2ef [ 38.598113] panic+0x26a/0x50e [ 38.601303] ? __warn_printk+0xf3/0xf3 [ 38.605177] ? preempt_schedule_common+0x45/0xc0 [ 38.609930] ? ___preempt_schedule+0x16/0x18 [ 38.614380] ? trace_hardirqs_on+0x55/0x210 [ 38.618705] kasan_end_report+0x43/0x49 [ 38.622682] kasan_report_error.cold+0xa7/0x1b9 executing program executing program executing program executing program executing program executing program [ 38.627354] ? vgem_gem_dumb_create+0x22c/0x240 [ 38.632020] __asan_report_load8_noabort+0x88/0x90 [ 38.636942] ? drm_gem_object_put_unlocked+0x40/0x180 [ 38.642142] ? vgem_gem_dumb_create+0x22c/0x240 [ 38.646819] vgem_gem_dumb_create+0x22c/0x240 [ 38.651302] drm_mode_create_dumb+0x27c/0x300 [ 38.655794] drm_ioctl_kernel+0x208/0x2a0 [ 38.659959] ? drm_mode_create_dumb+0x300/0x300 [ 38.664620] ? drm_ioctl_permit+0x210/0x210 [ 38.668967] ? __might_fault+0x192/0x1d0 [ 38.673016] drm_ioctl+0x507/0x9c0 executing program executing program [ 38.676552] ? drm_mode_create_dumb+0x300/0x300 [ 38.681224] ? drm_getstats+0x20/0x20 [ 38.685037] ? __fget+0x356/0x510 [ 38.688484] ? futex_exit_release+0x220/0x220 [ 38.692974] ? drm_getstats+0x20/0x20 [ 38.696781] do_vfs_ioctl+0xcdb/0x12e0 [ 38.700668] ? lock_downgrade+0x720/0x720 [ 38.704810] ? check_preemption_disabled+0x41/0x280 [ 38.709822] ? ioctl_preallocate+0x200/0x200 [ 38.714224] ? __fget+0x356/0x510 [ 38.717678] ? do_dup2+0x450/0x450 [ 38.721227] ? __se_sys_futex+0x298/0x3b0 [ 38.725370] ksys_ioctl+0x9b/0xc0 [ 38.728830] __x64_sys_ioctl+0x6f/0xb0 [ 38.732702] ? lockdep_hardirqs_on+0x3a8/0x5c0 [ 38.737274] do_syscall_64+0xf9/0x620 [ 38.741073] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.746255] RIP: 0033:0x44a579 [ 38.749430] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 [ 38.768345] RSP: 002b:00007fd6aff2e1f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 38.776048] RAX: ffffffffffffffda RBX: 00000000004cb4e8 RCX: 000000000044a579 [ 38.783307] RDX: 00000000200000c0 RSI: 00000000c02064b2 RDI: 0000000000000004 [ 38.790574] RBP: 00000000004cb4e0 R08: 0000000000000000 R09: 0000000000000000 [ 38.797834] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb4ec [ 38.805098] R13: 00007ffde95653df R14: 00007fd6aff2e300 R15: 0000000000022000 [ 38.812840] Kernel Offset: disabled [ 38.816456] Rebooting in 86400 seconds..