[ 62.332029][ T22] ================================================================== [ 62.332041][ T22] BUG: KFENCE: use-after-free read in kvm_fastop_exception+0xf6a/0x1058 [ 62.332041][ T22] [ 62.332077][ T22] Use-after-free read at 0xffff88823bce2020 (in kfence-#112): [ 62.332091][ T22] kvm_fastop_exception+0xf6a/0x1058 [ 62.332112][ T22] d_lookup+0xd8/0x170 [ 62.332135][ T22] lookup_dcache+0x1e/0x130 [ 62.332158][ T22] __lookup_hash+0x29/0x180 [ 62.332180][ T22] kern_path_locked+0x17e/0x320 [ 62.332205][ T22] handle_remove+0xa2/0x5fe [ 62.332230][ T22] devtmpfsd+0x1b9/0x2a3 [ 62.332251][ T22] kthread+0x3e5/0x4d0 [ 62.332274][ T22] ret_from_fork+0x1f/0x30 [ 62.332296][ T22] [ 62.332301][ T22] kfence-#112 [0xffff88823bce2000-0xffff88823bce2fff, size=4096, cache=names_cache] allocated by task 22: [ 62.332340][ T22] getname_kernel+0x4e/0x370 [ 62.332363][ T22] kern_path_locked+0x71/0x320 [ 62.332391][ T22] handle_remove+0xa2/0x5fe [ 62.332413][ T22] devtmpfsd+0x1b9/0x2a3 [ 62.332432][ T22] kthread+0x3e5/0x4d0 [ 62.332453][ T22] ret_from_fork+0x1f/0x30 [ 62.332474][ T22] [ 62.332474][ T22] freed by task 22: [ 62.332502][ T22] putname.part.0+0xe1/0x120 [ 62.332523][ T22] kern_path_locked+0xc2/0x320 [ 62.332547][ T22] handle_remove+0xa2/0x5fe [ 62.332570][ T22] devtmpfsd+0x1b9/0x2a3 [ 62.332590][ T22] kthread+0x3e5/0x4d0 [ 62.332611][ T22] ret_from_fork+0x1f/0x30 [ 62.332632][ T22] [ 62.332637][ T22] CPU: 1 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 62.332659][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.332671][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 62.332695][ 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 [ 62.332716][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 62.332734][ T22] RAX: 0000000036736376 RBX: ffff88806f1d0ef0 RCX: ffff88823bce2020 [ 62.332747][ T22] RDX: ffffed100de3a1e5 RSI: 0000000000000004 RDI: 0000000000000007 [ 62.332762][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806f1d0f20 [ 62.332775][ T22] R10: ffffed100de3a1e4 R11: 0000000000000000 R12: ffff88823bce2020 [ 62.332788][ T22] R13: ffff88823bce2020 R14: ffff88806f1d0f20 R15: dffffc0000000000 [ 62.332803][ T22] FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 [ 62.332824][ T22] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 62.332839][ T22] CR2: ffff88823bce2020 CR3: 000000000b68e000 CR4: 00000000001506e0 [ 62.332853][ T22] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 62.332866][ T22] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 62.332879][ T22] Call Trace: [ 62.332890][ T22] d_lookup+0xd8/0x170 [ 62.332917][ T22] lookup_dcache+0x1e/0x130 [ 62.332941][ T22] __lookup_hash+0x29/0x180 [ 62.332966][ T22] kern_path_locked+0x17e/0x320 [ 62.332993][ T22] ? filename_lookup+0x80/0x80 [ 62.333023][ T22] handle_remove+0xa2/0x5fe [ 62.333050][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 62.333078][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 62.333103][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 62.333133][ T22] ? find_held_lock+0x2d/0x110 [ 62.333156][ T22] ? devtmpfsd+0xaa/0x2a3 [ 62.333178][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 62.333201][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 62.333226][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 62.333254][ T22] devtmpfsd+0x1b9/0x2a3 [ 62.333278][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 62.333302][ T22] kthread+0x3e5/0x4d0 [ 62.333326][ T22] ? set_kthread_struct+0x130/0x130 [ 62.333352][ T22] ret_from_fork+0x1f/0x30 [ 62.333391][ T22] ================================================================== [ 62.333400][ T22] Kernel panic - not syncing: panic_on_warn set ... [ 62.333610][ T22] CPU: 1 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 62.333634][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.333647][ T22] Call Trace: [ 62.333654][ T22] dump_stack_lvl+0xcd/0x134 [ 62.333681][ T22] panic+0x2b0/0x6dd [ 62.333703][ T22] ? __warn_printk+0xf3/0xf3 [ 62.333739][ T22] ? kfence_report_error.cold+0x2f3/0xa56 [ 62.333772][ T22] kfence_report_error.cold+0x304/0xa56 [ 62.333800][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 62.333830][ T22] ? kfence_print_object+0x350/0x350 [ 62.333860][ T22] ? add_lock_to_list.constprop.0+0x185/0x370 [ 62.333921][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 62.333943][ T22] ? d_lookup+0xd8/0x170 [ 62.333964][ T22] ? lookup_dcache+0x1e/0x130 [ 62.333986][ T22] ? __lookup_hash+0x29/0x180 [ 62.334017][ T22] ? kern_path_locked+0x17e/0x320 [ 62.334041][ T22] ? handle_remove+0xa2/0x5fe [ 62.334084][ T22] ? devtmpfsd+0x1b9/0x2a3 [ 62.334106][ T22] ? kthread+0x3e5/0x4d0 [ 62.334128][ T22] ? ret_from_fork+0x1f/0x30 [ 62.334201][ T22] ? mark_lock+0xef/0x17b0 [ 62.334241][ T22] kfence_handle_page_fault+0x203/0x630 [ 62.334275][ T22] page_fault_oops+0x1c5/0x6b0 [ 62.334300][ T22] ? __sanitizer_cov_trace_const_cmp2+0x22/0x80 [ 62.334328][ T22] ? is_prefetch.constprop.0+0xb7/0x530 [ 62.334354][ T22] ? dump_pagetable+0xc0/0xc0 [ 62.334379][ T22] ? pgtable_bad+0x90/0x90 [ 62.334406][ T22] ? search_bpf_extables+0x1d1/0x2f0 [ 62.334431][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 62.334463][ T22] kernelmode_fixup_or_oops+0x219/0x280 [ 62.334494][ T22] __bad_area_nosemaphore+0x36d/0x400 [ 62.334521][ T22] ? spurious_kernel_fault+0x38d/0x5b0 [ 62.334551][ T22] do_kern_addr_fault+0x5b/0x70 [ 62.334579][ T22] exc_page_fault+0x155/0x180 [ 62.334607][ T22] asm_exc_page_fault+0x1e/0x30 [ 62.334631][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 62.334656][ 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 [ 62.334677][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 62.334697][ T22] RAX: 0000000036736376 RBX: ffff88806f1d0ef0 RCX: ffff88823bce2020 [ 62.334712][ T22] RDX: ffffed100de3a1e5 RSI: 0000000000000004 RDI: 0000000000000007 [ 62.334726][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806f1d0f20 [ 62.334741][ T22] R10: ffffed100de3a1e4 R11: 0000000000000000 R12: ffff88823bce2020 [ 62.334756][ T22] R13: ffff88823bce2020 R14: ffff88806f1d0f20 R15: dffffc0000000000 [ 62.334790][ T22] ? __d_lookup+0x372/0x720 [ 62.334829][ T22] d_lookup+0xd8/0x170 [ 62.334855][ T22] lookup_dcache+0x1e/0x130 [ 62.334933][ T22] __lookup_hash+0x29/0x180 [ 62.334959][ T22] kern_path_locked+0x17e/0x320 [ 62.334987][ T22] ? filename_lookup+0x80/0x80 [ 62.335031][ T22] handle_remove+0xa2/0x5fe [ 62.335063][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 62.335106][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 62.335134][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 62.335172][ T22] ? find_held_lock+0x2d/0x110 [ 62.335201][ T22] ? devtmpfsd+0xaa/0x2a3 [ 62.335226][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 62.335256][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 62.335284][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 62.335321][ T22] devtmpfsd+0x1b9/0x2a3 [ 62.335356][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 62.335385][ T22] kthread+0x3e5/0x4d0 [ 62.335411][ T22] ? set_kthread_struct+0x130/0x130 [ 62.335443][ T22] ret_from_fork+0x1f/0x30 [ 62.335841][ T22] Kernel Offset: disabled