Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.229' (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: [ 31.789564] hrtimer: interrupt took 58599 ns 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 executing program [ 31.931453] ================================================================== [ 31.938898] BUG: KASAN: use-after-free in vgem_gem_dumb_create+0x22c/0x240 [ 31.945937] Read of size 8 at addr ffff8880b148a400 by task syz-executor102/8215 [ 31.953462] [ 31.955089] CPU: 0 PID: 8215 Comm: syz-executor102 Not tainted 4.19.211-syzkaller #0 [ 31.962955] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 [ 31.972296] Call Trace: [ 31.974877] dump_stack+0x1fc/0x2ef [ 31.978504] print_address_description.cold+0x54/0x219 [ 31.983766] kasan_report_error.cold+0x8a/0x1b9 [ 31.988425] ? vgem_gem_dumb_create+0x22c/0x240 [ 31.993090] __asan_report_load8_noabort+0x88/0x90 [ 31.998013] ? audit_kill_trees+0x1c0/0x230 [ 32.002326] ? vgem_gem_dumb_create+0x22c/0x240 [ 32.006993] vgem_gem_dumb_create+0x22c/0x240 [ 32.011475] drm_mode_create_dumb+0x27c/0x300 [ 32.015956] drm_ioctl_kernel+0x208/0x2a0 [ 32.020106] ? drm_mode_create_dumb+0x300/0x300 [ 32.024760] ? drm_ioctl_permit+0x210/0x210 [ 32.029069] ? __might_fault+0x192/0x1d0 [ 32.033133] drm_ioctl+0x5a0/0x9e0 [ 32.036661] ? drm_mode_create_dumb+0x300/0x300 [ 32.041315] ? drm_getstats+0x20/0x20 [ 32.045099] ? _raw_spin_unlock_irq+0x24/0x80 [ 32.049579] ? lockdep_hardirqs_on+0x3a8/0x5c0 [ 32.054142] ? futex_exit_release+0x220/0x220 [ 32.058619] ? drm_getstats+0x20/0x20 [ 32.062408] do_vfs_ioctl+0xcdb/0x12e0 [ 32.066276] ? lock_downgrade+0x720/0x720 [ 32.070411] ? check_preemption_disabled+0x41/0x280 [ 32.075406] ? ioctl_preallocate+0x200/0x200 [ 32.079796] ? __fget+0x356/0x510 [ 32.083231] ? do_dup2+0x450/0x450 [ 32.086788] ? __se_sys_futex+0x298/0x3b0 [ 32.090922] ksys_ioctl+0x9b/0xc0 [ 32.094358] __x64_sys_ioctl+0x6f/0xb0 [ 32.098246] ? lockdep_hardirqs_on+0x3a8/0x5c0 [ 32.102812] do_syscall_64+0xf9/0x620 [ 32.106614] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 32.111784] RIP: 0033:0x7f76f3e78099 [ 32.115479] 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 b8 ff ff ff f7 d8 64 89 01 48 [ 32.134358] RSP: 002b:00007f76f3e25308 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 32.142050] RAX: ffffffffffffffda RBX: 00007f76f3efb408 RCX: 00007f76f3e78099 [ 32.149327] RDX: 0000000020000080 RSI: 00000000c02064b2 RDI: 0000000000000003 [ 32.156585] RBP: 00007f76f3efb400 R08: 0000000000000000 R09: 0000000000000000 [ 32.163836] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f76f3efb40c [ 32.171086] R13: 00007f76f3ec9074 R14: 6972642f7665642f R15: 0000000000022000 [ 32.178340] [ 32.179947] Allocated by task 8215: [ 32.183559] kmem_cache_alloc_trace+0x12f/0x380 [ 32.188209] __vgem_gem_create+0x44/0xf0 [ 32.192254] vgem_gem_dumb_create+0xcf/0x240 [ 32.196643] drm_mode_create_dumb+0x27c/0x300 [ 32.201119] drm_ioctl_kernel+0x208/0x2a0 [ 32.205250] drm_ioctl+0x5a0/0x9e0 [ 32.208767] do_vfs_ioctl+0xcdb/0x12e0 [ 32.212634] ksys_ioctl+0x9b/0xc0 [ 32.216073] __x64_sys_ioctl+0x6f/0xb0 [ 32.219942] do_syscall_64+0xf9/0x620 [ 32.223719] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 32.228884] [ 32.230491] Freed by task 8215: [ 32.233751] kfree+0xcc/0x210 [ 32.236839] drm_gem_object_free+0x91/0x1c0 [ 32.241141] drm_gem_object_put_unlocked+0xd1/0x180 [ 32.246140] vgem_gem_dumb_create+0x10c/0x240 [ 32.250618] drm_mode_create_dumb+0x27c/0x300 [ 32.255091] drm_ioctl_kernel+0x208/0x2a0 [ 32.259221] drm_ioctl+0x5a0/0x9e0 [ 32.262747] do_vfs_ioctl+0xcdb/0x12e0 [ 32.266615] ksys_ioctl+0x9b/0xc0 [ 32.270046] __x64_sys_ioctl+0x6f/0xb0 [ 32.273912] do_syscall_64+0xf9/0x620 [ 32.277691] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 32.282858] [ 32.284468] The buggy address belongs to the object at ffff8880b148a300 [ 32.284468] which belongs to the cache kmalloc-512 of size 512 [ 32.297130] The buggy address is located 256 bytes inside of [ 32.297130] 512-byte region [ffff8880b148a300, ffff8880b148a500) [ 32.308980] The buggy address belongs to the page: [ 32.313889] page:ffffea0002c52280 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0 [ 32.322013] flags: 0xfff00000000100(slab) [ 32.326140] raw: 00fff00000000100 ffffea0002a4f408 ffffea0002a4eb08 ffff88813bff0940 [ 32.334003] raw: 0000000000000000 ffff8880b148a080 0000000100000006 0000000000000000 [ 32.341860] page dumped because: kasan: bad access detected [ 32.347548] [ 32.349158] Memory state around the buggy address: [ 32.354076] ffff8880b148a300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 32.361443] ffff8880b148a380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 32.368783] >ffff8880b148a400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 32.376127] ^ [ 32.379488] ffff8880b148a480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 32.386835] ffff8880b148a500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 32.394191] ================================================================== [ 32.401541] Disabling lock debugging due to kernel taint [ 32.407940] Kernel panic - not syncing: panic_on_warn set ... [ 32.407940] [ 32.415315] CPU: 0 PID: 8215 Comm: syz-executor102 Tainted: G B 4.19.211-syzkaller #0 [ 32.424579] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 [ 32.433940] Call Trace: [ 32.436525] dump_stack+0x1fc/0x2ef [ 32.440145] panic+0x26a/0x50e [ 32.443317] ? __warn_printk+0xf3/0xf3 [ 32.447203] ? preempt_schedule_common+0x45/0xc0 [ 32.451959] ? ___preempt_schedule+0x16/0x18 [ 32.456347] ? trace_hardirqs_on+0x55/0x210 [ 32.460661] kasan_end_report+0x43/0x49 [ 32.464614] kasan_report_error.cold+0xa7/0x1b9 [ 32.469261] ? vgem_gem_dumb_create+0x22c/0x240 [ 32.473919] __asan_report_load8_noabort+0x88/0x90 [ 32.478830] ? audit_kill_trees+0x1c0/0x230 [ 32.483132] ? vgem_gem_dumb_create+0x22c/0x240 [ 32.487806] vgem_gem_dumb_create+0x22c/0x240 [ 32.492286] drm_mode_create_dumb+0x27c/0x300 [ 32.496764] drm_ioctl_kernel+0x208/0x2a0 [ 32.500895] ? drm_mode_create_dumb+0x300/0x300 [ 32.505550] ? drm_ioctl_permit+0x210/0x210 [ 32.509851] ? __might_fault+0x192/0x1d0 [ 32.513893] drm_ioctl+0x5a0/0x9e0 [ 32.517419] ? drm_mode_create_dumb+0x300/0x300 [ 32.522066] ? drm_getstats+0x20/0x20 [ 32.525871] ? _raw_spin_unlock_irq+0x24/0x80 [ 32.530361] ? lockdep_hardirqs_on+0x3a8/0x5c0 [ 32.534932] ? futex_exit_release+0x220/0x220 [ 32.539408] ? drm_getstats+0x20/0x20 [ 32.543194] do_vfs_ioctl+0xcdb/0x12e0 [ 32.547066] ? lock_downgrade+0x720/0x720 [ 32.551202] ? check_preemption_disabled+0x41/0x280 [ 32.556215] ? ioctl_preallocate+0x200/0x200 [ 32.560603] ? __fget+0x356/0x510 [ 32.564045] ? do_dup2+0x450/0x450 [ 32.567567] ? __se_sys_futex+0x298/0x3b0 [ 32.571713] ksys_ioctl+0x9b/0xc0 [ 32.575171] __x64_sys_ioctl+0x6f/0xb0 [ 32.579044] ? lockdep_hardirqs_on+0x3a8/0x5c0 [ 32.583617] do_syscall_64+0xf9/0x620 [ 32.587398] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 32.592573] RIP: 0033:0x7f76f3e78099 [ 32.596268] 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 b8 ff ff ff f7 d8 64 89 01 48 [ 32.615150] RSP: 002b:00007f76f3e25308 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 32.622838] RAX: ffffffffffffffda RBX: 00007f76f3efb408 RCX: 00007f76f3e78099 [ 32.630119] RDX: 0000000020000080 RSI: 00000000c02064b2 RDI: 0000000000000003 [ 32.637387] RBP: 00007f76f3efb400 R08: 0000000000000000 R09: 0000000000000000 [ 32.644650] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f76f3efb40c [ 32.651990] R13: 00007f76f3ec9074 R14: 6972642f7665642f R15: 0000000000022000 [ 32.659498] Kernel Offset: disabled [ 32.663116] Rebooting in 86400 seconds..