[ 64.372490][ T22] ================================================================== [ 64.372504][ T22] BUG: KFENCE: use-after-free read in kvm_fastop_exception+0xf6a/0x1058 [ 64.372504][ T22] [ 64.372554][ T22] Use-after-free read at 0xffff88823bcde020 (in kfence-#110): [ 64.372571][ T22] kvm_fastop_exception+0xf6a/0x1058 [ 64.372594][ T22] d_lookup+0xd8/0x170 [ 64.372619][ T22] lookup_dcache+0x1e/0x130 [ 64.372643][ T22] __lookup_hash+0x29/0x180 [ 64.372666][ T22] kern_path_locked+0x17e/0x320 [ 64.372693][ T22] handle_remove+0xa2/0x5fe [ 64.372720][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.372744][ T22] kthread+0x3e5/0x4d0 [ 64.372767][ T22] ret_from_fork+0x1f/0x30 [ 64.372791][ T22] [ 64.372795][ T22] kfence-#110: 0xffff88823bcde000-0xffff88823bcdefff, size=4096, cache=names_cache [ 64.372795][ T22] [ 64.372823][ T22] allocated by task 22 on cpu 0 at 64.372258s: [ 64.372857][ T22] getname_kernel+0x4e/0x370 [ 64.372882][ T22] kern_path_locked+0x71/0x320 [ 64.372906][ T22] handle_remove+0xa2/0x5fe [ 64.372931][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.372952][ T22] kthread+0x3e5/0x4d0 [ 64.372972][ T22] ret_from_fork+0x1f/0x30 [ 64.372994][ T22] [ 64.372997][ T22] freed by task 22 on cpu 0 at 64.372287s: [ 64.373036][ T22] putname.part.0+0xe1/0x120 [ 64.373059][ T22] kern_path_locked+0xc2/0x320 [ 64.373084][ T22] handle_remove+0xa2/0x5fe [ 64.373109][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.373130][ T22] kthread+0x3e5/0x4d0 [ 64.373152][ T22] ret_from_fork+0x1f/0x30 [ 64.373174][ T22] [ 64.373179][ T22] CPU: 0 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 64.373203][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.373217][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 64.373244][ T22] Code: d3 ed e9 cf f6 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 25 04 6f 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 15 0e 6f f8 bd [ 64.373267][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 64.373288][ T22] RAX: 0000000033736376 RBX: ffff88806ca09c28 RCX: ffff88823bcde020 [ 64.373304][ T22] RDX: ffffed100d94138c RSI: 0000000000000004 RDI: 0000000000000007 [ 64.373320][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806ca09c58 [ 64.373336][ T22] R10: ffffed100d94138b R11: 0000000000000000 R12: ffff88823bcde020 [ 64.373352][ T22] R13: ffff88823bcde020 R14: ffff88806ca09c58 R15: dffffc0000000000 [ 64.373369][ T22] FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 [ 64.373393][ T22] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 64.373410][ T22] CR2: ffff88823bcde020 CR3: 000000000b68e000 CR4: 00000000001506f0 [ 64.373426][ T22] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 64.373441][ T22] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 64.373455][ T22] Call Trace: [ 64.373466][ T22] d_lookup+0xd8/0x170 [ 64.373492][ T22] lookup_dcache+0x1e/0x130 [ 64.373516][ T22] __lookup_hash+0x29/0x180 [ 64.373544][ T22] kern_path_locked+0x17e/0x320 [ 64.373572][ T22] ? filename_lookup+0x80/0x80 [ 64.373605][ T22] handle_remove+0xa2/0x5fe [ 64.373632][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 64.373663][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 64.373691][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 64.373722][ T22] ? find_held_lock+0x2d/0x110 [ 64.373746][ T22] ? devtmpfsd+0xaa/0x2a3 [ 64.373770][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 64.373793][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 64.373825][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 64.373853][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.373879][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 64.373907][ T22] kthread+0x3e5/0x4d0 [ 64.373931][ T22] ? set_kthread_struct+0x130/0x130 [ 64.373960][ T22] ret_from_fork+0x1f/0x30 [ 64.373993][ T22] ================================================================== [ 64.374002][ T22] Kernel panic - not syncing: panic_on_warn set ... [ 64.374308][ T22] CPU: 0 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 64.374335][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.374350][ T22] Call Trace: [ 64.374359][ T22] dump_stack_lvl+0xcd/0x134 [ 64.374389][ T22] panic+0x2b0/0x6dd [ 64.374414][ T22] ? __warn_printk+0xf3/0xf3 [ 64.374452][ T22] ? kfence_report_error.cold+0x2f3/0xa56 [ 64.374488][ T22] kfence_report_error.cold+0x304/0xa56 [ 64.374518][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 64.374551][ T22] ? kfence_print_object+0x2e0/0x2e0 [ 64.374582][ T22] ? add_lock_to_list.constprop.0+0x185/0x370 [ 64.374609][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 64.374651][ T22] ? d_lookup+0xd8/0x170 [ 64.374677][ T22] ? lookup_dcache+0x1e/0x130 [ 64.374703][ T22] ? __lookup_hash+0x29/0x180 [ 64.374730][ T22] ? kern_path_locked+0x17e/0x320 [ 64.374758][ T22] ? handle_remove+0xa2/0x5fe [ 64.374787][ T22] ? devtmpfsd+0x1b9/0x2a3 [ 64.374818][ T22] ? kthread+0x3e5/0x4d0 [ 64.374844][ T22] ? ret_from_fork+0x1f/0x30 [ 64.374924][ T22] ? mark_lock+0xef/0x17b0 [ 64.374965][ T22] kfence_handle_page_fault+0x203/0x630 [ 64.375002][ T22] page_fault_oops+0x1c5/0x6b0 [ 64.375029][ T22] ? __sanitizer_cov_trace_const_cmp2+0x22/0x80 [ 64.375060][ T22] ? is_prefetch.constprop.0+0xb7/0x530 [ 64.375088][ T22] ? dump_pagetable+0xc0/0xc0 [ 64.375114][ T22] ? pgtable_bad+0x90/0x90 [ 64.375144][ T22] ? search_bpf_extables+0x1d1/0x2f0 [ 64.375170][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 64.375204][ T22] kernelmode_fixup_or_oops+0x219/0x280 [ 64.375235][ T22] __bad_area_nosemaphore+0x36d/0x400 [ 64.375264][ T22] ? spurious_kernel_fault+0x38d/0x5b0 [ 64.375297][ T22] do_kern_addr_fault+0x5b/0x70 [ 64.375325][ T22] exc_page_fault+0x155/0x180 [ 64.375353][ T22] asm_exc_page_fault+0x1e/0x30 [ 64.375381][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 64.375410][ T22] Code: d3 ed e9 cf f6 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 25 04 6f 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 15 0e 6f f8 bd [ 64.375434][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 64.375457][ T22] RAX: 0000000033736376 RBX: ffff88806ca09c28 RCX: ffff88823bcde020 [ 64.375475][ T22] RDX: ffffed100d94138c RSI: 0000000000000004 RDI: 0000000000000007 [ 64.375491][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806ca09c58 [ 64.375508][ T22] R10: ffffed100d94138b R11: 0000000000000000 R12: ffff88823bcde020 [ 64.375525][ T22] R13: ffff88823bcde020 R14: ffff88806ca09c58 R15: dffffc0000000000 [ 64.375561][ T22] ? __d_lookup+0x372/0x720 [ 64.375601][ T22] d_lookup+0xd8/0x170 [ 64.375632][ T22] lookup_dcache+0x1e/0x130 [ 64.375660][ T22] __lookup_hash+0x29/0x180 [ 64.375691][ T22] kern_path_locked+0x17e/0x320 [ 64.375722][ T22] ? filename_lookup+0x80/0x80 [ 64.375765][ T22] handle_remove+0xa2/0x5fe [ 64.375798][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 64.375838][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 64.375865][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 64.375902][ T22] ? find_held_lock+0x2d/0x110 [ 64.375930][ T22] ? devtmpfsd+0xaa/0x2a3 [ 64.375956][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 64.375982][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 64.376010][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 64.376045][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.376074][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 64.376107][ T22] kthread+0x3e5/0x4d0 [ 64.376132][ T22] ? set_kthread_struct+0x130/0x130 [ 64.376165][ T22] ret_from_fork+0x1f/0x30 [ 64.376586][ T22] Kernel Offset: disabled