[ 64.304945][ T22] ================================================================== [ 64.304957][ T22] BUG: KFENCE: use-after-free read in kvm_fastop_exception+0xf6a/0x1058 [ 64.304957][ T22] [ 64.305005][ T22] Use-after-free read at 0xffff88823bd04020 (in kfence-#129): [ 64.305020][ T22] kvm_fastop_exception+0xf6a/0x1058 [ 64.305040][ T22] d_lookup+0xd8/0x170 [ 64.305062][ T22] lookup_dcache+0x1e/0x130 [ 64.305084][ T22] __lookup_hash+0x29/0x180 [ 64.305107][ T22] kern_path_locked+0x17e/0x320 [ 64.305131][ T22] handle_remove+0xa2/0x5fe [ 64.305155][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.305176][ T22] kthread+0x3e5/0x4d0 [ 64.305197][ T22] ret_from_fork+0x1f/0x30 [ 64.305220][ T22] [ 64.305224][ T22] kfence-#129 [0xffff88823bd04000-0xffff88823bd04fff, size=4096, cache=names_cache] allocated by task 22: [ 64.305262][ T22] getname_kernel+0x4e/0x370 [ 64.305283][ T22] kern_path_locked+0x71/0x320 [ 64.305303][ T22] handle_remove+0xa2/0x5fe [ 64.305324][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.305342][ T22] kthread+0x3e5/0x4d0 [ 64.305362][ T22] ret_from_fork+0x1f/0x30 [ 64.305381][ T22] [ 64.305381][ T22] freed by task 22: [ 64.305407][ T22] putname.part.0+0xe1/0x120 [ 64.305426][ T22] kern_path_locked+0xc2/0x320 [ 64.305449][ T22] handle_remove+0xa2/0x5fe [ 64.305472][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.305498][ T22] kthread+0x3e5/0x4d0 [ 64.305519][ T22] ret_from_fork+0x1f/0x30 [ 64.305540][ T22] [ 64.305545][ T22] CPU: 1 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 64.305567][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.305579][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 64.305602][ T22] Code: d3 ed e9 bf 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 15 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 05 ea 6e f8 bd [ 64.305623][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 64.305642][ T22] RAX: 0000000032736376 RBX: ffff88806eae1938 RCX: ffff88823bd04020 [ 64.305658][ T22] RDX: ffffed100dd5c32e RSI: 0000000000000004 RDI: 0000000000000007 [ 64.305672][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806eae1968 [ 64.305686][ T22] R10: ffffed100dd5c32d R11: 0000000000000000 R12: ffff88823bd04020 [ 64.305700][ T22] R13: ffff88823bd04020 R14: ffff88806eae1968 R15: dffffc0000000000 [ 64.305716][ T22] FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 [ 64.305737][ T22] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 64.305753][ T22] CR2: ffff88823bd04020 CR3: 0000000072dc9000 CR4: 00000000001506e0 [ 64.305767][ T22] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 64.305780][ T22] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 64.305793][ T22] Call Trace: [ 64.305804][ T22] d_lookup+0xd8/0x170 [ 64.305829][ T22] lookup_dcache+0x1e/0x130 [ 64.305854][ T22] __lookup_hash+0x29/0x180 [ 64.305880][ T22] kern_path_locked+0x17e/0x320 [ 64.305906][ T22] ? filename_lookup+0x80/0x80 [ 64.305937][ T22] handle_remove+0xa2/0x5fe [ 64.305963][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 64.305992][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 64.306017][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 64.306045][ T22] ? find_held_lock+0x2d/0x110 [ 64.306065][ T22] ? devtmpfsd+0xaa/0x2a3 [ 64.306087][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 64.306109][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 64.306133][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 64.306159][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.306181][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 64.306206][ T22] kthread+0x3e5/0x4d0 [ 64.306229][ T22] ? set_kthread_struct+0x130/0x130 [ 64.306255][ T22] ret_from_fork+0x1f/0x30 [ 64.306282][ T22] ================================================================== [ 64.306290][ T22] Kernel panic - not syncing: panic_on_warn set ... [ 64.306550][ T22] CPU: 1 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 64.306575][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.306588][ T22] Call Trace: [ 64.306597][ T22] dump_stack_lvl+0xcd/0x134 [ 64.306623][ T22] panic+0x2b0/0x6dd [ 64.306647][ T22] ? __warn_printk+0xf3/0xf3 [ 64.306682][ T22] ? kfence_report_error.cold+0x2f3/0xa56 [ 64.306717][ T22] kfence_report_error.cold+0x304/0xa56 [ 64.306742][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 64.306770][ T22] ? kfence_print_object+0x350/0x350 [ 64.306799][ T22] ? add_lock_to_list.constprop.0+0x185/0x370 [ 64.306820][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 64.306839][ T22] ? d_lookup+0xd8/0x170 [ 64.306859][ T22] ? lookup_dcache+0x1e/0x130 [ 64.306880][ T22] ? __lookup_hash+0x29/0x180 [ 64.306902][ T22] ? kern_path_locked+0x17e/0x320 [ 64.306930][ T22] ? handle_remove+0xa2/0x5fe [ 64.306957][ T22] ? devtmpfsd+0x1b9/0x2a3 [ 64.306979][ T22] ? kthread+0x3e5/0x4d0 [ 64.307004][ T22] ? ret_from_fork+0x1f/0x30 [ 64.307080][ T22] ? mark_lock+0xef/0x17b0 [ 64.307118][ T22] kfence_handle_page_fault+0x203/0x630 [ 64.307153][ T22] page_fault_oops+0x1c5/0x6b0 [ 64.307177][ T22] ? __sanitizer_cov_trace_const_cmp2+0x22/0x80 [ 64.307205][ T22] ? is_prefetch.constprop.0+0xb7/0x530 [ 64.307230][ T22] ? dump_pagetable+0xc0/0xc0 [ 64.307255][ T22] ? pgtable_bad+0x90/0x90 [ 64.307283][ T22] ? search_bpf_extables+0x1d1/0x2f0 [ 64.307307][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 64.307338][ T22] kernelmode_fixup_or_oops+0x219/0x280 [ 64.307368][ T22] __bad_area_nosemaphore+0x36d/0x400 [ 64.307394][ T22] ? spurious_kernel_fault+0x38d/0x5b0 [ 64.307423][ T22] do_kern_addr_fault+0x5b/0x70 [ 64.307450][ T22] exc_page_fault+0x155/0x180 [ 64.307483][ T22] asm_exc_page_fault+0x1e/0x30 [ 64.307509][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 64.307534][ T22] Code: d3 ed e9 bf 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 15 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 05 ea 6e f8 bd [ 64.307555][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 64.307577][ T22] RAX: 0000000032736376 RBX: ffff88806eae1938 RCX: ffff88823bd04020 [ 64.307592][ T22] RDX: ffffed100dd5c32e RSI: 0000000000000004 RDI: 0000000000000007 [ 64.307606][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806eae1968 [ 64.307622][ T22] R10: ffffed100dd5c32d R11: 0000000000000000 R12: ffff88823bd04020 [ 64.307638][ T22] R13: ffff88823bd04020 R14: ffff88806eae1968 R15: dffffc0000000000 [ 64.307674][ T22] ? __d_lookup+0x372/0x720 [ 64.307713][ T22] d_lookup+0xd8/0x170 [ 64.307742][ T22] lookup_dcache+0x1e/0x130 [ 64.307768][ T22] __lookup_hash+0x29/0x180 [ 64.307799][ T22] kern_path_locked+0x17e/0x320 [ 64.307828][ T22] ? filename_lookup+0x80/0x80 [ 64.307871][ T22] handle_remove+0xa2/0x5fe [ 64.307904][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 64.307939][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 64.307966][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 64.308003][ T22] ? find_held_lock+0x2d/0x110 [ 64.308032][ T22] ? devtmpfsd+0xaa/0x2a3 [ 64.308057][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 64.308082][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 64.308109][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 64.308147][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.308175][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 64.308206][ T22] kthread+0x3e5/0x4d0 [ 64.308232][ T22] ? set_kthread_struct+0x130/0x130 [ 64.308262][ T22] ret_from_fork+0x1f/0x30 [ 64.308671][ T22] Kernel Offset: disabled [ 65.048853][ T22] Rebooting in 86400 seconds..