[ 67.857778][ T22] ================================================================== [ 67.857792][ T22] BUG: KFENCE: use-after-free read in kvm_fastop_exception+0xf6a/0x1058 [ 67.857792][ T22] [ 67.857842][ T22] Use-after-free read at 0xffff88823bd7a020 (in kfence-#188): [ 67.857857][ T22] kvm_fastop_exception+0xf6a/0x1058 [ 67.857879][ T22] d_lookup+0xd8/0x170 [ 67.857905][ T22] lookup_dcache+0x1e/0x130 [ 67.857930][ T22] __lookup_hash+0x29/0x180 [ 67.857954][ T22] kern_path_locked+0x17e/0x320 [ 67.857981][ T22] handle_remove+0xa2/0x5fe [ 67.858009][ T22] devtmpfsd+0x1b9/0x2a3 [ 67.858032][ T22] kthread+0x3e5/0x4d0 [ 67.858057][ T22] ret_from_fork+0x1f/0x30 [ 67.858082][ T22] [ 67.858087][ T22] kfence-#188 [0xffff88823bd7a000-0xffff88823bd7afff, size=4096, cache=names_cache] allocated by task 22: [ 67.858132][ T22] getname_kernel+0x4e/0x370 [ 67.858158][ T22] kern_path_locked+0x71/0x320 [ 67.858184][ T22] handle_remove+0xa2/0x5fe [ 67.858209][ T22] devtmpfsd+0x1b9/0x2a3 [ 67.858229][ T22] kthread+0x3e5/0x4d0 [ 67.858252][ T22] ret_from_fork+0x1f/0x30 [ 67.858272][ T22] [ 67.858272][ T22] freed by task 22: [ 67.858302][ T22] putname.part.0+0xe1/0x120 [ 67.858325][ T22] kern_path_locked+0xc2/0x320 [ 67.858351][ T22] handle_remove+0xa2/0x5fe [ 67.858377][ T22] devtmpfsd+0x1b9/0x2a3 [ 67.858398][ T22] kthread+0x3e5/0x4d0 [ 67.858421][ T22] ret_from_fork+0x1f/0x30 [ 67.858444][ T22] [ 67.858449][ T22] CPU: 1 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 67.858474][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 67.858488][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 67.858514][ 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 [ 67.858537][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 67.858557][ T22] RAX: 0000000032736376 RBX: ffff88806e05d1e0 RCX: ffff88823bd7a020 [ 67.858575][ T22] RDX: ffffed100dc0ba43 RSI: 0000000000000004 RDI: 0000000000000007 [ 67.858590][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806e05d210 [ 67.858606][ T22] R10: ffffed100dc0ba42 R11: 0000000000000000 R12: ffff88823bd7a020 [ 67.858622][ T22] R13: ffff88823bd7a020 R14: ffff88806e05d210 R15: dffffc0000000000 [ 67.858639][ T22] FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 [ 67.858664][ T22] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 67.858681][ T22] CR2: ffff88823bd7a020 CR3: 000000000b68e000 CR4: 00000000003506e0 [ 67.858697][ T22] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 67.858712][ T22] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 67.858726][ T22] Call Trace: [ 67.858737][ T22] d_lookup+0xd8/0x170 [ 67.858769][ T22] lookup_dcache+0x1e/0x130 [ 67.858795][ T22] __lookup_hash+0x29/0x180 [ 67.858823][ T22] kern_path_locked+0x17e/0x320 [ 67.858851][ T22] ? filename_lookup+0x80/0x80 [ 67.858884][ T22] handle_remove+0xa2/0x5fe [ 67.858912][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 67.858945][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 67.858973][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 67.859005][ T22] ? find_held_lock+0x2d/0x110 [ 67.859029][ T22] ? devtmpfsd+0xaa/0x2a3 [ 67.859052][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 67.859076][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 67.859102][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 67.859128][ T22] devtmpfsd+0x1b9/0x2a3 [ 67.859152][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 67.859178][ T22] kthread+0x3e5/0x4d0 [ 67.859200][ T22] ? set_kthread_struct+0x130/0x130 [ 67.859228][ T22] ret_from_fork+0x1f/0x30 [ 67.859258][ T22] ================================================================== [ 67.859267][ T22] Kernel panic - not syncing: panic_on_warn set ... [ 67.859578][ T22] CPU: 1 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 67.859605][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 67.859619][ T22] Call Trace: [ 67.859628][ T22] dump_stack_lvl+0xcd/0x134 [ 67.859656][ T22] panic+0x2b0/0x6dd [ 67.859681][ T22] ? __warn_printk+0xf3/0xf3 [ 67.859717][ T22] ? kfence_report_error.cold+0x2f3/0xa56 [ 67.859751][ T22] kfence_report_error.cold+0x304/0xa56 [ 67.859788][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 67.859818][ T22] ? kfence_print_object+0x350/0x350 [ 67.859850][ T22] ? add_lock_to_list.constprop.0+0x185/0x370 [ 67.859876][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 67.859900][ T22] ? d_lookup+0xd8/0x170 [ 67.859936][ T22] ? lookup_dcache+0x1e/0x130 [ 67.859963][ T22] ? __lookup_hash+0x29/0x180 [ 67.859990][ T22] ? kern_path_locked+0x17e/0x320 [ 67.860020][ T22] ? handle_remove+0xa2/0x5fe [ 67.860049][ T22] ? devtmpfsd+0x1b9/0x2a3 [ 67.860074][ T22] ? kthread+0x3e5/0x4d0 [ 67.860101][ T22] ? ret_from_fork+0x1f/0x30 [ 67.860180][ T22] ? mark_lock+0xef/0x17b0 [ 67.860222][ T22] kfence_handle_page_fault+0x203/0x630 [ 67.860276][ T22] page_fault_oops+0x1c5/0x6b0 [ 67.860303][ T22] ? __sanitizer_cov_trace_const_cmp2+0x22/0x80 [ 67.860335][ T22] ? is_prefetch.constprop.0+0xb7/0x530 [ 67.860363][ T22] ? dump_pagetable+0xc0/0xc0 [ 67.860389][ T22] ? pgtable_bad+0x90/0x90 [ 67.860419][ T22] ? search_bpf_extables+0x1d1/0x2f0 [ 67.860445][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 67.860479][ T22] kernelmode_fixup_or_oops+0x219/0x280 [ 67.860511][ T22] __bad_area_nosemaphore+0x36d/0x400 [ 67.860540][ T22] ? spurious_kernel_fault+0x38d/0x5b0 [ 67.860573][ T22] do_kern_addr_fault+0x5b/0x70 [ 67.860601][ T22] exc_page_fault+0x155/0x180 [ 67.860630][ T22] asm_exc_page_fault+0x1e/0x30 [ 67.860658][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 67.860684][ 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 [ 67.860707][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 67.860730][ T22] RAX: 0000000032736376 RBX: ffff88806e05d1e0 RCX: ffff88823bd7a020 [ 67.860748][ T22] RDX: ffffed100dc0ba43 RSI: 0000000000000004 RDI: 0000000000000007 [ 67.860771][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806e05d210 [ 67.860787][ T22] R10: ffffed100dc0ba42 R11: 0000000000000000 R12: ffff88823bd7a020 [ 67.860804][ T22] R13: ffff88823bd7a020 R14: ffff88806e05d210 R15: dffffc0000000000 [ 67.860842][ T22] ? __d_lookup+0x372/0x720 [ 67.860885][ T22] d_lookup+0xd8/0x170 [ 67.860917][ T22] lookup_dcache+0x1e/0x130 [ 67.860947][ T22] __lookup_hash+0x29/0x180 [ 67.860978][ T22] kern_path_locked+0x17e/0x320 [ 67.861009][ T22] ? filename_lookup+0x80/0x80 [ 67.861055][ T22] handle_remove+0xa2/0x5fe [ 67.861090][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 67.861128][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 67.861158][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 67.861199][ T22] ? find_held_lock+0x2d/0x110 [ 67.861230][ T22] ? devtmpfsd+0xaa/0x2a3 [ 67.861257][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 67.861284][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 67.861313][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 67.861353][ T22] devtmpfsd+0x1b9/0x2a3 [ 67.861383][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 67.861416][ T22] kthread+0x3e5/0x4d0 [ 67.861444][ T22] ? set_kthread_struct+0x130/0x130 [ 67.861475][ T22] ret_from_fork+0x1f/0x30 [ 67.861895][ T22] Kernel Offset: disabled