[ 68.038538][ T22] ================================================================== [ 68.038551][ T22] BUG: KFENCE: use-after-free read in kvm_fastop_exception+0xf6a/0x1058 [ 68.038551][ T22] [ 68.038600][ T22] Use-after-free read at 0xffff88823bd70020 (in kfence-#183): [ 68.038616][ T22] kvm_fastop_exception+0xf6a/0x1058 [ 68.038636][ T22] d_lookup+0xd8/0x170 [ 68.038662][ T22] lookup_dcache+0x1e/0x130 [ 68.038685][ T22] __lookup_hash+0x29/0x180 [ 68.038708][ T22] kern_path_locked+0x17e/0x320 [ 68.038734][ T22] handle_remove+0xa2/0x5fe [ 68.038761][ T22] devtmpfsd+0x1b9/0x2a3 [ 68.038784][ T22] kthread+0x3e5/0x4d0 [ 68.038808][ T22] ret_from_fork+0x1f/0x30 [ 68.038833][ T22] [ 68.038837][ T22] kfence-#183 [0xffff88823bd70000-0xffff88823bd70fff, size=4096, cache=names_cache] allocated by task 22: [ 68.038881][ T22] getname_kernel+0x4e/0x370 [ 68.038914][ T22] kern_path_locked+0x71/0x320 [ 68.038940][ T22] handle_remove+0xa2/0x5fe [ 68.038964][ T22] devtmpfsd+0x1b9/0x2a3 [ 68.038986][ T22] kthread+0x3e5/0x4d0 [ 68.039008][ T22] ret_from_fork+0x1f/0x30 [ 68.039031][ T22] [ 68.039031][ T22] freed by task 22: [ 68.039060][ T22] putname.part.0+0xe1/0x120 [ 68.039083][ T22] kern_path_locked+0xc2/0x320 [ 68.039109][ T22] handle_remove+0xa2/0x5fe [ 68.039133][ T22] devtmpfsd+0x1b9/0x2a3 [ 68.039154][ T22] kthread+0x3e5/0x4d0 [ 68.039176][ T22] ret_from_fork+0x1f/0x30 [ 68.039198][ T22] [ 68.039204][ T22] CPU: 1 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 68.039228][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 68.039240][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 68.039262][ T22] Code: d3 ed e9 af d4 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 05 e2 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 f5 eb 6e f8 bd [ 68.039281][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 68.039298][ T22] RAX: 0000000035736376 RBX: ffff88806e024330 RCX: ffff88823bd70020 [ 68.039313][ T22] RDX: ffffed100dc0486d RSI: 0000000000000004 RDI: 0000000000000007 [ 68.039327][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806e024360 [ 68.039339][ T22] R10: ffffed100dc0486c R11: 0000000000000001 R12: ffff88823bd70020 [ 68.039354][ T22] R13: ffff88823bd70020 R14: ffff88806e024360 R15: dffffc0000000000 [ 68.039370][ T22] FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 [ 68.039392][ T22] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 68.039407][ T22] CR2: ffff88823bd70020 CR3: 000000000b68e000 CR4: 00000000003506e0 [ 68.039422][ T22] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 68.039436][ T22] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 68.039449][ T22] Call Trace: [ 68.039459][ T22] d_lookup+0xd8/0x170 [ 68.039486][ T22] lookup_dcache+0x1e/0x130 [ 68.039511][ T22] __lookup_hash+0x29/0x180 [ 68.039537][ T22] kern_path_locked+0x17e/0x320 [ 68.039564][ T22] ? filename_lookup+0x80/0x80 [ 68.039595][ T22] handle_remove+0xa2/0x5fe [ 68.039625][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 68.039657][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 68.039685][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 68.039715][ T22] ? find_held_lock+0x2d/0x110 [ 68.039739][ T22] ? devtmpfsd+0xaa/0x2a3 [ 68.039763][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 68.039785][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 68.039810][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 68.039839][ T22] devtmpfsd+0x1b9/0x2a3 [ 68.039864][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 68.039892][ T22] kthread+0x3e5/0x4d0 [ 68.039926][ T22] ? set_kthread_struct+0x130/0x130 [ 68.039956][ T22] ret_from_fork+0x1f/0x30 [ 68.039988][ T22] ================================================================== [ 68.039996][ T22] Kernel panic - not syncing: panic_on_warn set ... [ 68.040233][ T22] CPU: 1 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 68.040261][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 68.040275][ T22] Call Trace: [ 68.040284][ T22] dump_stack_lvl+0xcd/0x134 [ 68.040312][ T22] panic+0x2b0/0x6dd [ 68.040336][ T22] ? __warn_printk+0xf3/0xf3 [ 68.040373][ T22] ? kfence_report_error.cold+0x2f3/0xa56 [ 68.040407][ T22] kfence_report_error.cold+0x304/0xa56 [ 68.040437][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 68.040468][ T22] ? kfence_print_object+0x350/0x350 [ 68.040501][ T22] ? add_lock_to_list.constprop.0+0x185/0x370 [ 68.040528][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 68.040552][ T22] ? d_lookup+0xd8/0x170 [ 68.040579][ T22] ? lookup_dcache+0x1e/0x130 [ 68.040606][ T22] ? __lookup_hash+0x29/0x180 [ 68.040633][ T22] ? kern_path_locked+0x17e/0x320 [ 68.040661][ T22] ? handle_remove+0xa2/0x5fe [ 68.040689][ T22] ? devtmpfsd+0x1b9/0x2a3 [ 68.040712][ T22] ? kthread+0x3e5/0x4d0 [ 68.040738][ T22] ? ret_from_fork+0x1f/0x30 [ 68.040834][ T22] kfence_handle_page_fault+0x203/0x630 [ 68.040874][ T22] page_fault_oops+0x1c5/0x6b0 [ 68.040901][ T22] ? __sanitizer_cov_trace_const_cmp2+0x22/0x80 [ 68.040939][ T22] ? is_prefetch.constprop.0+0xb7/0x530 [ 68.040967][ T22] ? dump_pagetable+0xc0/0xc0 [ 68.040994][ T22] ? pgtable_bad+0x90/0x90 [ 68.041024][ T22] ? search_bpf_extables+0x1d1/0x2f0 [ 68.041050][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 68.041084][ T22] kernelmode_fixup_or_oops+0x219/0x280 [ 68.041116][ T22] __bad_area_nosemaphore+0x36d/0x400 [ 68.041145][ T22] ? spurious_kernel_fault+0x38d/0x5b0 [ 68.041179][ T22] do_kern_addr_fault+0x5b/0x70 [ 68.041208][ T22] exc_page_fault+0x155/0x180 [ 68.041237][ T22] asm_exc_page_fault+0x1e/0x30 [ 68.041265][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 68.041292][ T22] Code: d3 ed e9 af d4 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 05 e2 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 f5 eb 6e f8 bd [ 68.041315][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 68.041337][ T22] RAX: 0000000035736376 RBX: ffff88806e024330 RCX: ffff88823bd70020 [ 68.041354][ T22] RDX: ffffed100dc0486d RSI: 0000000000000004 RDI: 0000000000000007 [ 68.041371][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806e024360 [ 68.041387][ T22] R10: ffffed100dc0486c R11: 0000000000000001 R12: ffff88823bd70020 [ 68.041404][ T22] R13: ffff88823bd70020 R14: ffff88806e024360 R15: dffffc0000000000 [ 68.041443][ T22] ? __d_lookup+0x372/0x720 [ 68.041485][ T22] d_lookup+0xd8/0x170 [ 68.041517][ T22] lookup_dcache+0x1e/0x130 [ 68.041547][ T22] __lookup_hash+0x29/0x180 [ 68.041581][ T22] kern_path_locked+0x17e/0x320 [ 68.041613][ T22] ? filename_lookup+0x80/0x80 [ 68.041660][ T22] handle_remove+0xa2/0x5fe [ 68.041696][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 68.041740][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 68.041770][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 68.041811][ T22] ? find_held_lock+0x2d/0x110 [ 68.041842][ T22] ? devtmpfsd+0xaa/0x2a3 [ 68.041886][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 68.041917][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 68.041945][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 68.041984][ T22] devtmpfsd+0x1b9/0x2a3 [ 68.042015][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 68.042048][ T22] kthread+0x3e5/0x4d0 [ 68.042075][ T22] ? set_kthread_struct+0x130/0x130 [ 68.042108][ T22] ret_from_fork+0x1f/0x30 [ 68.042533][ T22] Kernel Offset: disabled