[ 67.304074][ T22] ================================================================== [ 67.304086][ T22] BUG: KFENCE: use-after-free read in kvm_fastop_exception+0xf6a/0x1058 [ 67.304086][ T22] [ 67.304135][ T22] Use-after-free read at 0xffff88823bd66020 (in kfence-#178): [ 67.304150][ T22] kvm_fastop_exception+0xf6a/0x1058 [ 67.304172][ T22] d_lookup+0xd8/0x170 [ 67.304195][ T22] lookup_dcache+0x1e/0x130 [ 67.304217][ T22] __lookup_hash+0x29/0x180 [ 67.304240][ T22] kern_path_locked+0x17e/0x320 [ 67.304264][ T22] handle_remove+0xa2/0x5fe [ 67.304285][ T22] devtmpfsd+0x1b9/0x2a3 [ 67.304306][ T22] kthread+0x3e5/0x4d0 [ 67.304329][ T22] ret_from_fork+0x1f/0x30 [ 67.304351][ T22] [ 67.304355][ T22] kfence-#178: 0xffff88823bd66000-0xffff88823bd66fff, size=4096, cache=names_cache [ 67.304355][ T22] [ 67.304375][ T22] allocated by task 22 on cpu 0 at 67.303856s: [ 67.304404][ T22] getname_kernel+0x4e/0x370 [ 67.304428][ T22] kern_path_locked+0x71/0x320 [ 67.304451][ T22] handle_remove+0xa2/0x5fe [ 67.304471][ T22] devtmpfsd+0x1b9/0x2a3 [ 67.304490][ T22] kthread+0x3e5/0x4d0 [ 67.304511][ T22] ret_from_fork+0x1f/0x30 [ 67.304531][ T22] [ 67.304534][ T22] freed by task 22 on cpu 0 at 67.303887s: [ 67.304567][ T22] putname.part.0+0xe1/0x120 [ 67.304589][ T22] kern_path_locked+0xc2/0x320 [ 67.304613][ T22] handle_remove+0xa2/0x5fe [ 67.304632][ T22] devtmpfsd+0x1b9/0x2a3 [ 67.304653][ T22] kthread+0x3e5/0x4d0 [ 67.304678][ T22] ret_from_fork+0x1f/0x30 [ 67.304699][ T22] [ 67.304703][ T22] CPU: 0 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-next-20210907-syzkaller #0 [ 67.304726][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 67.304739][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 67.304765][ T22] Code: d3 ed e9 ff 66 6d f8 49 8d 0e 48 83 e1 f8 4c 8b 21 41 8d 0e 83 e1 07 c1 e1 03 49 d3 ec e9 55 74 6d 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 45 7e 6d f8 bd [ 67.304790][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 67.304809][ T22] RAX: 0000000036736376 RBX: ffff88806ce37938 RCX: ffff88823bd66020 [ 67.304824][ T22] RDX: ffffed100d9c6f2e RSI: 0000000000000004 RDI: 0000000000000007 [ 67.304838][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806ce37968 [ 67.304852][ T22] R10: ffffed100d9c6f2d R11: 0000000000000000 R12: ffff88823bd66020 [ 67.304867][ T22] R13: ffff88823bd66020 R14: ffff88806ce37968 R15: dffffc0000000000 [ 67.304883][ T22] FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 [ 67.304904][ T22] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 67.304921][ T22] CR2: ffff88823bd66020 CR3: 000000001ddca000 CR4: 00000000001506f0 [ 67.304936][ T22] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 67.304949][ T22] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 67.304963][ T22] Call Trace: [ 67.304974][ T22] d_lookup+0xd8/0x170 [ 67.305005][ T22] lookup_dcache+0x1e/0x130 [ 67.305031][ T22] __lookup_hash+0x29/0x180 [ 67.305056][ T22] kern_path_locked+0x17e/0x320 [ 67.305084][ T22] ? filename_lookup+0x80/0x80 [ 67.305116][ T22] handle_remove+0xa2/0x5fe [ 67.305138][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 67.305164][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 67.305189][ T22] ? finish_task_switch.isra.0+0x217/0xa20 [ 67.305218][ T22] ? find_held_lock+0x2d/0x110 [ 67.305240][ T22] ? devtmpfsd+0xaa/0x2a3 [ 67.305262][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 67.305284][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 67.305308][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 67.305334][ T22] devtmpfsd+0x1b9/0x2a3 [ 67.305358][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 67.305386][ T22] kthread+0x3e5/0x4d0 [ 67.305408][ T22] ? set_kthread_struct+0x130/0x130 [ 67.305435][ T22] ret_from_fork+0x1f/0x30 [ 67.305464][ T22] ================================================================== [ 67.305473][ T22] Kernel panic - not syncing: panic_on_warn set ... [ 67.305708][ T22] CPU: 0 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-next-20210907-syzkaller #0 [ 67.305731][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 67.305744][ T22] Call Trace: [ 67.305752][ T22] dump_stack_lvl+0xcd/0x134 [ 67.305781][ T22] panic+0x2b0/0x6dd [ 67.305809][ T22] ? __warn_printk+0xf3/0xf3 [ 67.305848][ T22] ? kfence_report_error.cold+0x2f3/0xa56 [ 67.305884][ T22] kfence_report_error.cold+0x304/0xa56 [ 67.305916][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 67.305946][ T22] ? kfence_print_object+0x2e0/0x2e0 [ 67.305976][ T22] ? add_lock_to_list.constprop.0+0x185/0x370 [ 67.306006][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 67.306030][ T22] ? d_lookup+0xd8/0x170 [ 67.306055][ T22] ? lookup_dcache+0x1e/0x130 [ 67.306080][ T22] ? __lookup_hash+0x29/0x180 [ 67.306106][ T22] ? kern_path_locked+0x17e/0x320 [ 67.306133][ T22] ? handle_remove+0xa2/0x5fe [ 67.306155][ T22] ? devtmpfsd+0x1b9/0x2a3 [ 67.306179][ T22] ? kthread+0x3e5/0x4d0 [ 67.306203][ T22] ? ret_from_fork+0x1f/0x30 [ 67.306276][ T22] ? mark_lock+0xef/0x17b0 [ 67.306312][ T22] kfence_handle_page_fault+0x203/0x630 [ 67.306348][ T22] page_fault_oops+0x1c5/0x6b0 [ 67.306372][ T22] ? __sanitizer_cov_trace_const_cmp2+0x22/0x80 [ 67.306400][ T22] ? is_prefetch.constprop.0+0xb7/0x530 [ 67.306426][ T22] ? dump_pagetable+0xc0/0xc0 [ 67.306450][ T22] ? pgtable_bad+0x90/0x90 [ 67.306476][ T22] ? search_bpf_extables+0x1d1/0x2f0 [ 67.306500][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 67.306533][ T22] kernelmode_fixup_or_oops+0x219/0x280 [ 67.306562][ T22] __bad_area_nosemaphore+0x36d/0x400 [ 67.306588][ T22] ? spurious_kernel_fault+0x38d/0x5b0 [ 67.306618][ T22] do_kern_addr_fault+0x5b/0x70 [ 67.306645][ T22] exc_page_fault+0x155/0x180 [ 67.306672][ T22] asm_exc_page_fault+0x1e/0x30 [ 67.306699][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 67.306725][ T22] Code: d3 ed e9 ff 66 6d f8 49 8d 0e 48 83 e1 f8 4c 8b 21 41 8d 0e 83 e1 07 c1 e1 03 49 d3 ec e9 55 74 6d 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 45 7e 6d f8 bd [ 67.306746][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 67.306767][ T22] RAX: 0000000036736376 RBX: ffff88806ce37938 RCX: ffff88823bd66020 [ 67.306783][ T22] RDX: ffffed100d9c6f2e RSI: 0000000000000004 RDI: 0000000000000007 [ 67.306798][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806ce37968 [ 67.306813][ T22] R10: ffffed100d9c6f2d R11: 0000000000000000 R12: ffff88823bd66020 [ 67.306829][ T22] R13: ffff88823bd66020 R14: ffff88806ce37968 R15: dffffc0000000000 [ 67.306864][ T22] ? __d_lookup+0x372/0x720 [ 67.306909][ T22] d_lookup+0xd8/0x170 [ 67.306937][ T22] lookup_dcache+0x1e/0x130 [ 67.306965][ T22] __lookup_hash+0x29/0x180 [ 67.306999][ T22] kern_path_locked+0x17e/0x320 [ 67.307029][ T22] ? filename_lookup+0x80/0x80 [ 67.307072][ T22] handle_remove+0xa2/0x5fe [ 67.307100][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 67.307131][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 67.307158][ T22] ? finish_task_switch.isra.0+0x217/0xa20 [ 67.307195][ T22] ? find_held_lock+0x2d/0x110 [ 67.307223][ T22] ? devtmpfsd+0xaa/0x2a3 [ 67.307249][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 67.307274][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 67.307301][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 67.307337][ T22] devtmpfsd+0x1b9/0x2a3 [ 67.307365][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 67.307396][ T22] kthread+0x3e5/0x4d0 [ 67.307421][ T22] ? set_kthread_struct+0x130/0x130 [ 67.307452][ T22] ret_from_fork+0x1f/0x30 [ 67.308936][ T22] Kernel Offset: disabled