[ 62.463882][ T22] ================================================================== [ 62.463893][ T22] BUG: KFENCE: use-after-free read in kvm_fastop_exception+0xf6a/0x1058 [ 62.463893][ T22] [ 62.463936][ T22] Use-after-free read at 0xffff88823bcdc020 (in kfence-#109): [ 62.463951][ T22] kvm_fastop_exception+0xf6a/0x1058 [ 62.463971][ T22] d_lookup+0xd8/0x170 [ 62.463994][ T22] lookup_dcache+0x1e/0x130 [ 62.464013][ T22] __lookup_hash+0x29/0x180 [ 62.464032][ T22] kern_path_locked+0x17e/0x320 [ 62.464053][ T22] handle_remove+0xa2/0x5fe [ 62.464076][ T22] devtmpfsd+0x1b9/0x2a3 [ 62.464094][ T22] kthread+0x3e5/0x4d0 [ 62.464114][ T22] ret_from_fork+0x1f/0x30 [ 62.464134][ T22] [ 62.464137][ T22] kfence-#109 [0xffff88823bcdc000-0xffff88823bcdcfff, size=4096, cache=names_cache] allocated by task 22: [ 62.464172][ T22] getname_kernel+0x4e/0x370 [ 62.464193][ T22] kern_path_locked+0x71/0x320 [ 62.464213][ T22] handle_remove+0xa2/0x5fe [ 62.464233][ T22] devtmpfsd+0x1b9/0x2a3 [ 62.464250][ T22] kthread+0x3e5/0x4d0 [ 62.464268][ T22] ret_from_fork+0x1f/0x30 [ 62.464286][ T22] [ 62.464286][ T22] freed by task 22: [ 62.464310][ T22] putname.part.0+0xe1/0x120 [ 62.464328][ T22] kern_path_locked+0xc2/0x320 [ 62.464349][ T22] handle_remove+0xa2/0x5fe [ 62.464368][ T22] devtmpfsd+0x1b9/0x2a3 [ 62.464385][ T22] kthread+0x3e5/0x4d0 [ 62.464403][ T22] ret_from_fork+0x1f/0x30 [ 62.464421][ T22] [ 62.464426][ T22] CPU: 0 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 62.464445][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.464455][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 62.464476][ 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 [ 62.464494][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 62.464510][ T22] RAX: 0000000032736376 RBX: ffff88806ff8b938 RCX: ffff88823bcdc020 [ 62.464524][ T22] RDX: ffffed100dff172e RSI: 0000000000000004 RDI: 0000000000000007 [ 62.464536][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806ff8b968 [ 62.464548][ T22] R10: ffffed100dff172d R11: 0000000000000001 R12: ffff88823bcdc020 [ 62.464561][ T22] R13: ffff88823bcdc020 R14: ffff88806ff8b968 R15: dffffc0000000000 [ 62.464574][ T22] FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 [ 62.464593][ T22] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 62.464606][ T22] CR2: ffff88823bcdc020 CR3: 0000000071d72000 CR4: 00000000001506f0 [ 62.464618][ T22] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 62.464629][ T22] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 62.464641][ T22] Call Trace: [ 62.464651][ T22] d_lookup+0xd8/0x170 [ 62.464673][ T22] lookup_dcache+0x1e/0x130 [ 62.464694][ T22] __lookup_hash+0x29/0x180 [ 62.464716][ T22] kern_path_locked+0x17e/0x320 [ 62.464739][ T22] ? filename_lookup+0x80/0x80 [ 62.464770][ T22] handle_remove+0xa2/0x5fe [ 62.464793][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 62.464819][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 62.464841][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 62.464866][ T22] ? find_held_lock+0x2d/0x110 [ 62.464885][ T22] ? devtmpfsd+0xaa/0x2a3 [ 62.464904][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 62.464924][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 62.464945][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 62.464968][ T22] devtmpfsd+0x1b9/0x2a3 [ 62.464989][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 62.465011][ T22] kthread+0x3e5/0x4d0 [ 62.465031][ T22] ? set_kthread_struct+0x130/0x130 [ 62.465054][ T22] ret_from_fork+0x1f/0x30 [ 62.465080][ T22] ================================================================== [ 62.465087][ T22] Kernel panic - not syncing: panic_on_warn set ... [ 62.465237][ T22] CPU: 0 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 [ 62.465258][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.465268][ T22] Call Trace: [ 62.465276][ T22] dump_stack_lvl+0xcd/0x134 [ 62.465298][ T22] panic+0x2b0/0x6dd [ 62.465317][ T22] ? __warn_printk+0xf3/0xf3 [ 62.465346][ T22] ? kfence_report_error.cold+0x2f3/0xa56 [ 62.465374][ T22] kfence_report_error.cold+0x304/0xa56 [ 62.465397][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 62.465421][ T22] ? kfence_print_object+0x350/0x350 [ 62.465446][ T22] ? add_lock_to_list.constprop.0+0x185/0x370 [ 62.465467][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 62.465486][ T22] ? d_lookup+0xd8/0x170 [ 62.465507][ T22] ? lookup_dcache+0x1e/0x130 [ 62.465528][ T22] ? __lookup_hash+0x29/0x180 [ 62.465549][ T22] ? kern_path_locked+0x17e/0x320 [ 62.465572][ T22] ? handle_remove+0xa2/0x5fe [ 62.465595][ T22] ? devtmpfsd+0x1b9/0x2a3 [ 62.465615][ T22] ? kthread+0x3e5/0x4d0 [ 62.465636][ T22] ? ret_from_fork+0x1f/0x30 [ 62.465724][ T22] kfence_handle_page_fault+0x203/0x630 [ 62.465761][ T22] page_fault_oops+0x1c5/0x6b0 [ 62.465783][ T22] ? __sanitizer_cov_trace_const_cmp2+0x22/0x80 [ 62.465808][ T22] ? is_prefetch.constprop.0+0xb7/0x530 [ 62.465830][ T22] ? dump_pagetable+0xc0/0xc0 [ 62.465851][ T22] ? pgtable_bad+0x90/0x90 [ 62.465874][ T22] ? search_bpf_extables+0x1d1/0x2f0 [ 62.465895][ T22] ? kvm_fastop_exception+0xf6a/0x1058 [ 62.465922][ T22] kernelmode_fixup_or_oops+0x219/0x280 [ 62.465947][ T22] __bad_area_nosemaphore+0x36d/0x400 [ 62.465969][ T22] ? spurious_kernel_fault+0x38d/0x5b0 [ 62.465995][ T22] do_kern_addr_fault+0x5b/0x70 [ 62.466018][ T22] exc_page_fault+0x155/0x180 [ 62.466041][ T22] asm_exc_page_fault+0x1e/0x30 [ 62.466063][ T22] RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 [ 62.466084][ 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 [ 62.466102][ T22] RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 [ 62.466119][ T22] RAX: 0000000032736376 RBX: ffff88806ff8b938 RCX: ffff88823bcdc020 [ 62.466134][ T22] RDX: ffffed100dff172e RSI: 0000000000000004 RDI: 0000000000000007 [ 62.466147][ T22] RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806ff8b968 [ 62.466159][ T22] R10: ffffed100dff172d R11: 0000000000000001 R12: ffff88823bcdc020 [ 62.466173][ T22] R13: ffff88823bcdc020 R14: ffff88806ff8b968 R15: dffffc0000000000 [ 62.466202][ T22] ? __d_lookup+0x372/0x720 [ 62.466235][ T22] d_lookup+0xd8/0x170 [ 62.466261][ T22] lookup_dcache+0x1e/0x130 [ 62.466284][ T22] __lookup_hash+0x29/0x180 [ 62.466310][ T22] kern_path_locked+0x17e/0x320 [ 62.466335][ T22] ? filename_lookup+0x80/0x80 [ 62.466371][ T22] handle_remove+0xa2/0x5fe [ 62.466399][ T22] ? cacheinfo_cpu_online.cold+0x3e/0x3e [ 62.466429][ T22] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 62.466452][ T22] ? finish_task_switch.isra.0+0x232/0xa50 [ 62.466484][ T22] ? find_held_lock+0x2d/0x110 [ 62.466508][ T22] ? devtmpfsd+0xaa/0x2a3 [ 62.466529][ T22] ? lock_downgrade+0x6e0/0x6e0 [ 62.466551][ T22] ? do_raw_spin_lock+0x120/0x2b0 [ 62.466574][ T22] ? rwlock_bug.part.0+0x90/0x90 [ 62.466606][ T22] devtmpfsd+0x1b9/0x2a3 [ 62.466629][ T22] ? dmar_validate_one_drhd+0x24d/0x24d [ 62.466655][ T22] kthread+0x3e5/0x4d0 [ 62.466677][ T22] ? set_kthread_struct+0x130/0x130 [ 62.466704][ T22] ret_from_fork+0x1f/0x30 [ 62.467076][ T22] Kernel Offset: disabled