[ 64.284898][ T22] ================================================================== [ 64.284909][ T22] BUG: KFENCE: use-after-free read in kvm_fastop_exception+0xf6a/0x1058 [ 64.284909][ T22] [ 64.284955][ T22] Use-after-free read at 0xffff88823bcfa020 (in kfence-#124): [ 64.284968][ T22] kvm_fastop_exception+0xf6a/0x1058 [ 64.284985][ T22] d_lookup+0xd8/0x170 [ 64.285006][ T22] lookup_dcache+0x1e/0x130 [ 64.285025][ T22] __lookup_hash+0x29/0x180 [ 64.285044][ T22] kern_path_locked+0x17e/0x320 [ 64.285066][ T22] handle_remove+0xa2/0x5fe [ 64.285088][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.285107][ T22] kthread+0x3e5/0x4d0 [ 64.285127][ T22] ret_from_fork+0x1f/0x30 [ 64.285147][ T22] [ 64.285150][ T22] kfence-#124 [0xffff88823bcfa000-0xffff88823bcfafff, size=4096, cache=names_cache] allocated by task 22: [ 64.285185][ T22] getname_kernel+0x4e/0x370 [ 64.285206][ T22] kern_path_locked+0x71/0x320 [ 64.285226][ T22] handle_remove+0xa2/0x5fe [ 64.285246][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.285262][ T22] kthread+0x3e5/0x4d0 [ 64.285281][ T22] ret_from_fork+0x1f/0x30 [ 64.285298][ T22] [ 64.285298][ T22] freed by task 22: [ 64.285322][ T22] putname.part.0+0xe1/0x120 [ 64.285340][ T22] kern_path_locked+0xc2/0x320 [ 64.285361][ T22] handle_remove+0xa2/0x5fe [ 64.285380][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.285397][ T22] kthread+0x3e5/0x4d0 [ 64.285415][ T22] ret_from_fork+0x1f/0x30 [ 64.285433][ T22] [ 64.285437][ T22] CPU: 0 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 64.285457][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.285468][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 64.285488][ 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 [ 64.285507][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 64.285523][ T22] RAX: 0000000032736376 RBX: ffff88806e780910 RCX: ffff88823bcfa020 [ 64.285537][ T22] RDX: ffffed100dcf0129 RSI: 0000000000000004 RDI: 0000000000000007 [ 64.285549][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806e780940 [ 64.285560][ T22] R10: ffffed100dcf0128 R11: 0000000000000000 R12: ffff88823bcfa020 [ 64.285573][ T22] R13: ffff88823bcfa020 R14: ffff88806e780940 R15: dffffc0000000000 [ 64.285586][ T22] FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 [ 64.285605][ T22] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 64.285619][ T22] CR2: ffff88823bcfa020 CR3: 0000000072b4e000 CR4: 00000000001506f0 [ 64.285632][ T22] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 64.285643][ T22] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 64.285655][ T22] Call Trace: [ 64.285665][ T22] d_lookup+0xd8/0x170 [ 64.285687][ T22] lookup_dcache+0x1e/0x130 [ 64.285708][ T22] __lookup_hash+0x29/0x180 [ 64.285730][ T22] kern_path_locked+0x17e/0x320 [ 64.285753][ T22] ? filename_lookup+0x80/0x80 [ 64.285780][ T22] handle_remove+0xa2/0x5fe [ 64.285803][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 64.285834][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 64.285856][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 64.285881][ T22] ? find_held_lock+0x2d/0x110 [ 64.285900][ T22] ? devtmpfsd+0xaa/0x2a3 [ 64.285919][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 64.285938][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 64.285960][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 64.285983][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.286003][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 64.286026][ T22] kthread+0x3e5/0x4d0 [ 64.286046][ T22] ? set_kthread_struct+0x130/0x130 [ 64.286070][ T22] ret_from_fork+0x1f/0x30 [ 64.286096][ T22] ================================================================== [ 64.286103][ T22] Kernel panic - not syncing: panic_on_warn set ... [ 64.286292][ T22] CPU: 0 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 64.286311][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.286322][ T22] Call Trace: [ 64.286329][ T22] dump_stack_lvl+0xcd/0x134 [ 64.286352][ T22] panic+0x2b0/0x6dd [ 64.286372][ T22] ? __warn_printk+0xf3/0xf3 [ 64.286400][ T22] ? kfence_report_error.cold+0x2f3/0xa56 [ 64.286428][ T22] kfence_report_error.cold+0x304/0xa56 [ 64.286451][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 64.286476][ T22] ? kfence_print_object+0x350/0x350 [ 64.286501][ T22] ? add_lock_to_list.constprop.0+0x185/0x370 [ 64.286522][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 64.286541][ T22] ? d_lookup+0xd8/0x170 [ 64.286562][ T22] ? lookup_dcache+0x1e/0x130 [ 64.286583][ T22] ? __lookup_hash+0x29/0x180 [ 64.286604][ T22] ? kern_path_locked+0x17e/0x320 [ 64.286628][ T22] ? handle_remove+0xa2/0x5fe [ 64.286650][ T22] ? devtmpfsd+0x1b9/0x2a3 [ 64.286670][ T22] ? kthread+0x3e5/0x4d0 [ 64.286691][ T22] ? ret_from_fork+0x1f/0x30 [ 64.286753][ T22] ? mark_lock+0xef/0x17b0 [ 64.286784][ T22] kfence_handle_page_fault+0x203/0x630 [ 64.286814][ T22] page_fault_oops+0x1c5/0x6b0 [ 64.286840][ T22] ? __sanitizer_cov_trace_const_cmp2+0x22/0x80 [ 64.286865][ T22] ? is_prefetch.constprop.0+0xb7/0x530 [ 64.286887][ T22] ? dump_pagetable+0xc0/0xc0 [ 64.286907][ T22] ? pgtable_bad+0x90/0x90 [ 64.286930][ T22] ? search_bpf_extables+0x1d1/0x2f0 [ 64.286951][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 64.286977][ T22] kernelmode_fixup_or_oops+0x219/0x280 [ 64.287003][ T22] __bad_area_nosemaphore+0x36d/0x400 [ 64.287025][ T22] ? spurious_kernel_fault+0x38d/0x5b0 [ 64.287051][ T22] do_kern_addr_fault+0x5b/0x70 [ 64.287074][ T22] exc_page_fault+0x155/0x180 [ 64.287097][ T22] asm_exc_page_fault+0x1e/0x30 [ 64.287119][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 64.287140][ 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 [ 64.287157][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 64.287174][ T22] RAX: 0000000032736376 RBX: ffff88806e780910 RCX: ffff88823bcfa020 [ 64.287188][ T22] RDX: ffffed100dcf0129 RSI: 0000000000000004 RDI: 0000000000000007 [ 64.287201][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806e780940 [ 64.287214][ T22] R10: ffffed100dcf0128 R11: 0000000000000000 R12: ffff88823bcfa020 [ 64.287227][ T22] R13: ffff88823bcfa020 R14: ffff88806e780940 R15: dffffc0000000000 [ 64.287257][ T22] ? __d_lookup+0x372/0x720 [ 64.287290][ T22] d_lookup+0xd8/0x170 [ 64.287315][ T22] lookup_dcache+0x1e/0x130 [ 64.287340][ T22] __lookup_hash+0x29/0x180 [ 64.287366][ T22] kern_path_locked+0x17e/0x320 [ 64.287391][ T22] ? filename_lookup+0x80/0x80 [ 64.287427][ T22] handle_remove+0xa2/0x5fe [ 64.287454][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 64.287485][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 64.287508][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 64.287540][ T22] ? find_held_lock+0x2d/0x110 [ 64.287564][ T22] ? devtmpfsd+0xaa/0x2a3 [ 64.287586][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 64.287607][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 64.287631][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 64.287662][ T22] devtmpfsd+0x1b9/0x2a3 [ 64.287686][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 64.287712][ T22] kthread+0x3e5/0x4d0 [ 64.287734][ T22] ? set_kthread_struct+0x130/0x130 [ 64.287760][ T22] ret_from_fork+0x1f/0x30 [ 64.288158][ T22] Kernel Offset: disabled