[ 64.245706][ T22] ================================================================== [ 64.245718][ T22] BUG: KFENCE: use-after-free read in kvm_fastop_exception+0xf6a/0x1058 [ 64.245718][ T22] [ 64.245772][ T22] Use-after-free read at 0xffff88823bd06020 (in kfence-#130): [ 64.245786][ T22] kvm_fastop_exception+0xf6a/0x1058 [ 64.245806][ T22] d_lookup+0xd8/0x170 [ 64.245827][ T22] lookup_dcache+0x1e/0x130 [ 64.245848][ T22] __lookup_hash+0x29/0x180 [ 64.245869][ T22] kern_path_locked+0x17e/0x320 [ 64.245891][ T22] handle_remove+0xa2/0x5fe [ 64.245916][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.245936][ T22] kthread+0x3e5/0x4d0 [ 64.245959][ T22] ret_from_fork+0x1f/0x30 [ 64.245981][ T22] [ 64.245985][ T22] kfence-#130 [0xffff88823bd06000-0xffff88823bd06fff, size=4096, cache=names_cache] allocated by task 22: [ 64.246023][ T22] getname_kernel+0x4e/0x370 [ 64.246045][ T22] kern_path_locked+0x71/0x320 [ 64.246066][ T22] handle_remove+0xa2/0x5fe [ 64.246086][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.246103][ T22] kthread+0x3e5/0x4d0 [ 64.246125][ T22] ret_from_fork+0x1f/0x30 [ 64.246146][ T22] [ 64.246146][ T22] freed by task 22: [ 64.246171][ T22] putname.part.0+0xe1/0x120 [ 64.246191][ T22] kern_path_locked+0xc2/0x320 [ 64.246213][ T22] handle_remove+0xa2/0x5fe [ 64.246235][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.246253][ T22] kthread+0x3e5/0x4d0 [ 64.246274][ T22] ret_from_fork+0x1f/0x30 [ 64.246295][ T22] [ 64.246300][ T22] CPU: 0 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 64.246321][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.246333][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 64.246365][ T22] Code: d3 ed e9 df d2 6e f8 49 8d 0e 48 83 e1 f8 4c 8b 21 41 8d 0e 83 e1 07 c1 e1 03 49 d3 ec e9 35 e0 6e f8 49 8d 4d 00 48 83 e1 f8 <4c> 8b 21 41 8d 4d 00 83 e1 07 c1 e1 03 49 d3 ec e9 25 ea 6e f8 bd [ 64.246386][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 64.246404][ T22] RAX: 0000000032736376 RBX: ffff88806f278910 RCX: ffff88823bd06020 [ 64.246419][ T22] RDX: ffffed100de4f129 RSI: 0000000000000004 RDI: 0000000000000007 [ 64.246433][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806f278940 [ 64.246445][ T22] R10: ffffed100de4f128 R11: 0000000000000000 R12: ffff88823bd06020 [ 64.246459][ T22] R13: ffff88823bd06020 R14: ffff88806f278940 R15: dffffc0000000000 [ 64.246474][ T22] FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 [ 64.246495][ T22] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 64.246510][ T22] CR2: ffff88823bd06020 CR3: 000000000b68e000 CR4: 00000000001506f0 [ 64.246524][ T22] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 64.246538][ T22] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 64.246551][ T22] Call Trace: [ 64.246563][ T22] d_lookup+0xd8/0x170 [ 64.246589][ T22] lookup_dcache+0x1e/0x130 [ 64.246613][ T22] __lookup_hash+0x29/0x180 [ 64.246638][ T22] kern_path_locked+0x17e/0x320 [ 64.246664][ T22] ? filename_lookup+0x80/0x80 [ 64.246696][ T22] handle_remove+0xa2/0x5fe [ 64.246723][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 64.246750][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 64.246773][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 64.246800][ T22] ? find_held_lock+0x2d/0x110 [ 64.246822][ T22] ? devtmpfsd+0xaa/0x2a3 [ 64.246843][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 64.246864][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 64.246888][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 64.246915][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.246938][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 64.246962][ T22] kthread+0x3e5/0x4d0 [ 64.246985][ T22] ? set_kthread_struct+0x130/0x130 [ 64.247011][ T22] ret_from_fork+0x1f/0x30 [ 64.247041][ T22] ================================================================== [ 64.247049][ T22] Kernel panic - not syncing: panic_on_warn set ... [ 64.247366][ T22] CPU: 0 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 64.247390][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.247402][ T22] Call Trace: [ 64.247414][ T22] dump_stack_lvl+0xcd/0x134 [ 64.247442][ T22] panic+0x2b0/0x6dd [ 64.247464][ T22] ? __warn_printk+0xf3/0xf3 [ 64.247499][ T22] ? kfence_report_error.cold+0x2f3/0xa56 [ 64.247531][ T22] kfence_report_error.cold+0x304/0xa56 [ 64.247558][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 64.247586][ T22] ? kfence_print_object+0x350/0x350 [ 64.247616][ T22] ? add_lock_to_list.constprop.0+0x185/0x370 [ 64.247640][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 64.247662][ T22] ? d_lookup+0xd8/0x170 [ 64.247686][ T22] ? lookup_dcache+0x1e/0x130 [ 64.247710][ T22] ? __lookup_hash+0x29/0x180 [ 64.247735][ T22] ? kern_path_locked+0x17e/0x320 [ 64.247762][ T22] ? handle_remove+0xa2/0x5fe [ 64.247788][ T22] ? devtmpfsd+0x1b9/0x2a3 [ 64.247812][ T22] ? kthread+0x3e5/0x4d0 [ 64.247837][ T22] ? ret_from_fork+0x1f/0x30 [ 64.247913][ T22] ? mark_lock+0xef/0x17b0 [ 64.247953][ T22] kfence_handle_page_fault+0x203/0x630 [ 64.247988][ T22] page_fault_oops+0x1c5/0x6b0 [ 64.248014][ T22] ? __sanitizer_cov_trace_const_cmp2+0x22/0x80 [ 64.248043][ T22] ? is_prefetch.constprop.0+0xb7/0x530 [ 64.248069][ T22] ? dump_pagetable+0xc0/0xc0 [ 64.248094][ T22] ? pgtable_bad+0x90/0x90 [ 64.248122][ T22] ? search_bpf_extables+0x1d1/0x2f0 [ 64.248146][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 64.248179][ T22] kernelmode_fixup_or_oops+0x219/0x280 [ 64.248209][ T22] __bad_area_nosemaphore+0x36d/0x400 [ 64.248236][ T22] ? spurious_kernel_fault+0x38d/0x5b0 [ 64.248267][ T22] do_kern_addr_fault+0x5b/0x70 [ 64.248295][ T22] exc_page_fault+0x155/0x180 [ 64.248322][ T22] asm_exc_page_fault+0x1e/0x30 [ 64.248355][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 64.248382][ T22] Code: d3 ed e9 df d2 6e f8 49 8d 0e 48 83 e1 f8 4c 8b 21 41 8d 0e 83 e1 07 c1 e1 03 49 d3 ec e9 35 e0 6e f8 49 8d 4d 00 48 83 e1 f8 <4c> 8b 21 41 8d 4d 00 83 e1 07 c1 e1 03 49 d3 ec e9 25 ea 6e f8 bd [ 64.248404][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 64.248425][ T22] RAX: 0000000032736376 RBX: ffff88806f278910 RCX: ffff88823bd06020 [ 64.248442][ T22] RDX: ffffed100de4f129 RSI: 0000000000000004 RDI: 0000000000000007 [ 64.248457][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806f278940 [ 64.248472][ T22] R10: ffffed100de4f128 R11: 0000000000000000 R12: ffff88823bd06020 [ 64.248488][ T22] R13: ffff88823bd06020 R14: ffff88806f278940 R15: dffffc0000000000 [ 64.248524][ T22] ? __d_lookup+0x372/0x720 [ 64.248565][ T22] d_lookup+0xd8/0x170 [ 64.248594][ T22] lookup_dcache+0x1e/0x130 [ 64.248623][ T22] __lookup_hash+0x29/0x180 [ 64.248654][ T22] kern_path_locked+0x17e/0x320 [ 64.248684][ T22] ? filename_lookup+0x80/0x80 [ 64.248729][ T22] handle_remove+0xa2/0x5fe [ 64.248761][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 64.248797][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 64.248824][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 64.248862][ T22] ? find_held_lock+0x2d/0x110 [ 64.248891][ T22] ? devtmpfsd+0xaa/0x2a3 [ 64.248916][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 64.248942][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 64.248969][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 64.249007][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.249035][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 64.249065][ T22] kthread+0x3e5/0x4d0 [ 64.249091][ T22] ? set_kthread_struct+0x130/0x130 [ 64.249123][ T22] ret_from_fork+0x1f/0x30 [ 64.249541][ T22] Kernel Offset: disabled