[ 68.218333][ T22] ================================================================== [ 68.218345][ T22] BUG: KFENCE: use-after-free read in kvm_fastop_exception+0xf6a/0x1058 [ 68.218345][ T22] [ 68.218391][ T22] Use-after-free read at 0xffff88823bdc6020 (in kfence-#226): [ 68.218404][ T22] kvm_fastop_exception+0xf6a/0x1058 [ 68.218422][ T22] d_lookup+0xd8/0x170 [ 68.218443][ T22] lookup_dcache+0x1e/0x130 [ 68.218462][ T22] __lookup_hash+0x29/0x180 [ 68.218481][ T22] kern_path_locked+0x17e/0x320 [ 68.218502][ T22] handle_remove+0xa2/0x5fe [ 68.218525][ T22] devtmpfsd+0x1b9/0x2a3 [ 68.218544][ T22] kthread+0x3e5/0x4d0 [ 68.218564][ T22] ret_from_fork+0x1f/0x30 [ 68.218583][ T22] [ 68.218587][ T22] kfence-#226 [0xffff88823bdc6000-0xffff88823bdc6fff, size=4096, cache=names_cache] allocated by task 22: [ 68.218622][ T22] getname_kernel+0x4e/0x370 [ 68.218642][ T22] kern_path_locked+0x71/0x320 [ 68.218670][ T22] handle_remove+0xa2/0x5fe [ 68.218690][ T22] devtmpfsd+0x1b9/0x2a3 [ 68.218706][ T22] kthread+0x3e5/0x4d0 [ 68.218724][ T22] ret_from_fork+0x1f/0x30 [ 68.218742][ T22] [ 68.218742][ T22] freed by task 22: [ 68.218765][ T22] putname.part.0+0xe1/0x120 [ 68.218784][ T22] kern_path_locked+0xc2/0x320 [ 68.218804][ T22] handle_remove+0xa2/0x5fe [ 68.218823][ T22] devtmpfsd+0x1b9/0x2a3 [ 68.218840][ T22] kthread+0x3e5/0x4d0 [ 68.218858][ T22] ret_from_fork+0x1f/0x30 [ 68.218876][ T22] [ 68.218880][ T22] CPU: 1 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 68.218899][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 68.218910][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 68.218931][ 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 [ 68.218948][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 68.218965][ T22] RAX: 0000003475736376 RBX: ffff88806ffbc620 RCX: ffff88823bdc6020 [ 68.218979][ T22] RDX: ffffed100dff78cb RSI: 0000000000000005 RDI: 0000000000000007 [ 68.218990][ T22] RBP: 0000000000000005 R08: 0000000000000000 R09: ffff88806ffbc650 [ 68.219002][ T22] R10: ffffed100dff78ca R11: 0000000000000000 R12: ffff88823bdc6020 [ 68.219015][ T22] R13: ffff88823bdc6020 R14: ffff88806ffbc650 R15: dffffc0000000000 [ 68.219028][ T22] FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 [ 68.219048][ T22] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 68.219062][ T22] CR2: ffff88823bdc6020 CR3: 0000000016433000 CR4: 00000000001506e0 [ 68.219074][ T22] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 68.219085][ T22] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 68.219097][ T22] Call Trace: [ 68.219107][ T22] d_lookup+0xd8/0x170 [ 68.219128][ T22] lookup_dcache+0x1e/0x130 [ 68.219150][ T22] __lookup_hash+0x29/0x180 [ 68.219172][ T22] kern_path_locked+0x17e/0x320 [ 68.219195][ T22] ? filename_lookup+0x80/0x80 [ 68.219222][ T22] handle_remove+0xa2/0x5fe [ 68.219245][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 68.219269][ T22] ? trace_hardirqs_on+0x38/0x1c0 [ 68.219292][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 68.219318][ T22] ? find_held_lock+0x2d/0x110 [ 68.219337][ T22] ? devtmpfsd+0xaa/0x2a3 [ 68.219356][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 68.219376][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 68.219397][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 68.219420][ T22] devtmpfsd+0x1b9/0x2a3 [ 68.219441][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 68.219463][ T22] kthread+0x3e5/0x4d0 [ 68.219483][ T22] ? set_kthread_struct+0x130/0x130 [ 68.219506][ T22] ret_from_fork+0x1f/0x30 [ 68.219532][ T22] ================================================================== [ 68.219539][ T22] Kernel panic - not syncing: panic_on_warn set ... [ 68.219762][ T22] CPU: 1 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 68.219782][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 68.219793][ T22] Call Trace: [ 68.219800][ T22] dump_stack_lvl+0xcd/0x134 [ 68.219822][ T22] panic+0x2b0/0x6dd [ 68.219842][ T22] ? __warn_printk+0xf3/0xf3 [ 68.219870][ T22] ? kfence_report_error.cold+0x2f3/0xa56 [ 68.219897][ T22] kfence_report_error.cold+0x304/0xa56 [ 68.219920][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 68.219944][ T22] ? kfence_print_object+0x350/0x350 [ 68.219969][ T22] ? add_lock_to_list.constprop.0+0x185/0x370 [ 68.219990][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 68.220009][ T22] ? d_lookup+0xd8/0x170 [ 68.220030][ T22] ? lookup_dcache+0x1e/0x130 [ 68.220051][ T22] ? __lookup_hash+0x29/0x180 [ 68.220073][ T22] ? kern_path_locked+0x17e/0x320 [ 68.220096][ T22] ? handle_remove+0xa2/0x5fe [ 68.220119][ T22] ? devtmpfsd+0x1b9/0x2a3 [ 68.220138][ T22] ? kthread+0x3e5/0x4d0 [ 68.220160][ T22] ? ret_from_fork+0x1f/0x30 [ 68.220222][ T22] ? mark_lock+0xef/0x17b0 [ 68.220254][ T22] kfence_handle_page_fault+0x203/0x630 [ 68.220284][ T22] page_fault_oops+0x1c5/0x6b0 [ 68.220305][ T22] ? __sanitizer_cov_trace_const_cmp2+0x22/0x80 [ 68.220329][ T22] ? is_prefetch.constprop.0+0xb7/0x530 [ 68.220351][ T22] ? dump_pagetable+0xc0/0xc0 [ 68.220372][ T22] ? pgtable_bad+0x90/0x90 [ 68.220395][ T22] ? search_bpf_extables+0x1d1/0x2f0 [ 68.220416][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 68.220442][ T22] kernelmode_fixup_or_oops+0x219/0x280 [ 68.220468][ T22] __bad_area_nosemaphore+0x36d/0x400 [ 68.220490][ T22] ? spurious_kernel_fault+0x38d/0x5b0 [ 68.220516][ T22] do_kern_addr_fault+0x5b/0x70 [ 68.220539][ T22] exc_page_fault+0x155/0x180 [ 68.220561][ T22] asm_exc_page_fault+0x1e/0x30 [ 68.220583][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 68.220605][ 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 [ 68.220623][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 68.220640][ T22] RAX: 0000003475736376 RBX: ffff88806ffbc620 RCX: ffff88823bdc6020 [ 68.220659][ T22] RDX: ffffed100dff78cb RSI: 0000000000000005 RDI: 0000000000000007 [ 68.220672][ T22] RBP: 0000000000000005 R08: 0000000000000000 R09: ffff88806ffbc650 [ 68.220685][ T22] R10: ffffed100dff78ca R11: 0000000000000000 R12: ffff88823bdc6020 [ 68.220698][ T22] R13: ffff88823bdc6020 R14: ffff88806ffbc650 R15: dffffc0000000000 [ 68.220728][ T22] ? __d_lookup+0x372/0x720 [ 68.220760][ T22] d_lookup+0xd8/0x170 [ 68.220785][ T22] lookup_dcache+0x1e/0x130 [ 68.220809][ T22] __lookup_hash+0x29/0x180 [ 68.220834][ T22] kern_path_locked+0x17e/0x320 [ 68.220859][ T22] ? filename_lookup+0x80/0x80 [ 68.220896][ T22] handle_remove+0xa2/0x5fe [ 68.220923][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 68.220950][ T22] ? trace_hardirqs_on+0x38/0x1c0 [ 68.220975][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 68.221009][ T22] ? find_held_lock+0x2d/0x110 [ 68.221033][ T22] ? devtmpfsd+0xaa/0x2a3 [ 68.221055][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 68.221076][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 68.221099][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 68.221131][ T22] devtmpfsd+0x1b9/0x2a3 [ 68.221156][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 68.221182][ T22] kthread+0x3e5/0x4d0 [ 68.221204][ T22] ? set_kthread_struct+0x130/0x130 [ 68.221231][ T22] ret_from_fork+0x1f/0x30 [ 68.221653][ T22] Kernel Offset: disabled