* linux-next: not-present page at swap_vma_readahead() @ 2020-04-14 14:32 Qian Cai 2020-04-14 21:22 ` Qian Cai 0 siblings, 1 reply; 9+ messages in thread From: Qian Cai @ 2020-04-14 14:32 UTC (permalink / raw) To: Linux-MM; +Cc: LKML, Minchan Kim, Huang Ying, Hugh Dickins, Andrew Morton Fuzzers are unhappy. Thoughts? [34944.838318][T48906] BUG: unable to handle page fault for address: ffff888cb196bfe8 [34944.845970][T48906] #PF: supervisor read access in kernel mode [34944.847199][T50168] futex_wake_op: trinity-c58 tries to shift op by -1; fix this program [34944.851855][T48906] #PF: error_code(0x0000) - not-present page [34944.851866][T48906] PGD f63401067 P4D f63401067 PUD 1079630067 PMD 10794a3067 PTE 800ffff34e694060 [34944.874964][T48906] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI [34944.881289][T48906] CPU: 72 PID: 48906 Comm: trinity-c85 Tainted: G L 5.7.0-rc1-next-20200414+ #8 [34944.891559][T48906] Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 [34944.900860][T48906] RIP: 0010:swapin_readahead+0x40a/0x85f swap_vma_readahead at mm/swap_state.c:741 (inlined by) swapin_readahead at mm/swap_state.c:785 [34944.906394][T48906] Code: 6c 24 70 44 8b 64 24 0c 4c 89 6c 24 18 eb 13 41 83 c4 01 49 83 c6 08 44 3b 64 24 20 0f 84 38 03 00 00 4c 89 f7 e8 66 74 04 00 <4d> 8b 3e 49 f7 c7 9f ff ff ff 74 d9 48 c7 c7 a0 83 23 91 e8 4e 74 [34944.925989][T48906] RSP: 0018:ffffc9002622f620 EFLAGS: 00010246 [34944.931960][T48906] RAX: 0000000000000000 RBX: ffffc9002622f8d8 RCX: ffffffff902370aa [34944.939849][T48906] RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff888cb196bfe8 [34944.947737][T48906] RBP: ffffc9002622f758 R08: 0000000000000000 R09: ffffed112d8078e7 [34944.955625][T48906] R10: ffff88896c03c737 R11: ffffed112d8078e6 R12: 0000000000000000 [34944.963580][T48906] R13: ffffc9002622f690 R14: ffff888cb196bfe8 R15: ffff888cb196c000 [34944.971479][T48906] FS: 00007f17c465a740(0000) GS:ffff889032c00000(0000) knlGS:0000000000000000 [34944.980329][T48906] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [34944.986820][T48906] CR2: ffff888cb196bfe8 CR3: 0000000c17964000 CR4: 00000000003406e0 [34944.994709][T48906] Call Trace: [34944.997895][T48906] ? exit_swap_address_space+0x160/0x160 [34945.003429][T48906] ? lookup_swap_cache+0x144/0x410 [34945.008516][T48906] ? swapcache_prepare+0x20/0x20 [34945.013352][T48906] do_swap_page+0x4ef/0xe70 do_swap_page at mm/memory.c:3141 [34945.017751][T48906] ? unmap_mapping_range+0x30/0x30 [34945.022763][T48906] __handle_mm_fault+0xb80/0xbe0 [34945.027601][T48906] ? copy_page_range+0x420/0x420 [34945.032438][T48906] handle_mm_fault+0xdc/0x2e0 [34945.037013][T48906] do_page_fault+0x2cb/0x9d7 [34945.041607][T48906] page_fault+0x34/0x40 [34945.045655][T48906] RIP: 0010:strncpy_from_user+0xc9/0x2a0 [34945.051184][T48906] Code: 14 00 00 4c 01 e8 0f 92 c1 0f 82 45 01 00 00 48 39 c2 0f 82 3c 01 00 00 0f 01 cb 0f ae e8 49 83 fd 07 0f 86 b7 01 00 00 31 f6 <49> 8b 14 24 85 f6 0f 85 9b 01 00 00 49 8d 45 f8 4c 89 6d c0 49 89 [34945.070775][T48906] RSP: 0018:ffffc9002622fb28 EFLAGS: 00050246 [34945.076742][T48906] RAX: 0000000000000fe0 RBX: ffff888c17830040 RCX: 0000000000000000 [34945.084626][T48906] RDX: 00007ffffffff000 RSI: 0000000000000000 RDI: ffff888c178314d0 [34945.092516][T48906] RBP: ffffc9002622fb70 R08: 0000000000000fe0 R09: fffff940065ea9e1 [34945.100402][T48906] R10: ffffea0032f54f07 R11: fffff940065ea9e0 R12: 0000000000000000 [34945.108288][T48906] R13: 0000000000000fe0 R14: ffff888cbd53c060 R15: 0000000000000fe0 [34945.116184][T48906] ? strncpy_from_user+0x96/0x2a0 [34945.121106][T48906] getname_flags+0x6a/0x220 [34945.125502][T48906] do_renameat2+0x17c/0x7e0 [34945.129895][T48906] ? user_path_create+0x40/0x40 [34945.134642][T48906] ? register_lock_class+0xb40/0xb40 [34945.139824][T48906] ? match_held_lock+0x20/0x250 [34945.144569][T48906] ? find_held_lock+0xca/0xf0 [34945.149140][T48906] ? __kasan_check_read+0x11/0x20 [34945.154062][T48906] ? perf_syscall_enter+0xf9/0x370 [34945.159065][T48906] ? lock_downgrade+0x3e0/0x3e0 [34945.163804][T48906] ? check_flags.part.28+0x86/0x220 [34945.168896][T48906] ? rcu_read_lock_sched_held+0xac/0xe0 [34945.174339][T48906] ? do_syscall_64+0x79/0xaf0 [34945.178907][T48906] ? rcu_read_lock_bh_held+0xc0/0xc0 [34945.184091][T48906] __x64_sys_rename+0x3b/0x50 [34945.188659][T48906] do_syscall_64+0xcc/0xaf0 [34945.193050][T48906] ? perf_call_bpf_enter+0x1a0/0x1a0 [34945.198230][T48906] ? syscall_return_slowpath+0x580/0x580 [34945.203760][T48906] ? entry_SYSCALL_64_after_hwframe+0x3e/0xb3 [34945.209725][T48906] ? trace_hardirqs_off_caller+0x3a/0x150 [34945.215340][T48906] ? trace_hardirqs_off_thunk+0x1a/0x1c [34945.220780][T48906] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [34945.226568][T48906] RIP: 0033:0x7f17c3f5c839 [34945.230872][T48906] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1f f6 2c 00 f7 d8 64 89 01 48 [34945.250461][T48906] RSP: 002b:00007fff822be2d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 [34945.258802][T48906] RAX: ffffffffffffffda RBX: 0000000000000052 RCX: 00007f17c3f5c839 [34945.266685][T48906] RDX: 00000000000000e8 RSI: 0000000000000000 RDI: 0000000000000000 ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: linux-next: not-present page at swap_vma_readahead() 2020-04-14 14:32 linux-next: not-present page at swap_vma_readahead() Qian Cai @ 2020-04-14 21:22 ` Qian Cai 2020-04-15 2:01 ` Huang, Ying 0 siblings, 1 reply; 9+ messages in thread From: Qian Cai @ 2020-04-14 21:22 UTC (permalink / raw) To: Linux-MM; +Cc: LKML, Minchan Kim, Huang Ying, Hugh Dickins, Andrew Morton > On Apr 14, 2020, at 10:32 AM, Qian Cai <cai@lca.pw> wrote: > > Fuzzers are unhappy. Thoughts? This is rather to reproduce. All the traces so far are from copy_from_user() to trigger a page fault, and then it dereferences a bad pte in swap_vma_readahead(), for (i = 0, pte = ra_info.ptes; i < ra_info.nr_pte; i++, pte++) { pentry = *pte; <— crashed here. if (pte_none(pentry)) [12561.167450][ T8470] Unable to handle kernel paging request at virtual address ffff000eec8dffe8 [12561.176391][ T8470] Mem abort info: [12561.179916][ T8470] ESR = 0x96000007 [12561.183702][ T8470] EC = 0x25: DABT (current EL), IL = 32 bits [12561.189897][ T8470] SET = 0, FnV = 0 [12561.193681][ T8470] EA = 0, S1PTW = 0 [12561.197622][ T8470] Data abort info: [12561.201232][ T8470] ISV = 0, ISS = 0x00000007 [12561.205905][ T8470] CM = 0, WnR = 0 [12561.209605][ T8470] swapper pgtable: 64k pages, 48-bit VAs, pgdp=00000000813d0000 [12561.217231][ T8470] [ffff000eec8dffe8] pgd=00000097fcfd0003, pud=00000097fcfd0003, pmd=00000097fcc10003, pte=0068000f6c8d0712 [12561.229049][ T8470] Internal error: Oops: 96000007 [#1] SMP [12561.234628][ T8470] Modules linked in: nfnetlink thunderx2_pmu processor ip_tables xfs libcrc32c sd_mod ahci libahci mlx5_core libata dm_mirror dm_region_hash dm_log dm_mod efivarfs [12561.250854][ T8470] CPU: 147 PID: 8470 Comm: trinity-c147 Tainted: G L 5.7.0-rc1-next-20200414 #5 [12561.261031][ T8470] Hardware name: HPE Apollo 70 /C01_APACHE_MB , BIOS L50_5.13_1.11 06/18/2019 [12561.271472][ T8470] pstate: 60400009 (nZCv daif +PAN -UAO) [12561.276978][ T8470] pc : swap_vma_readahead+0x360/0x568 [12561.282207][ T8470] lr : swap_vma_readahead+0x360/0x568 [12561.287442][ T8470] sp : e4ff000eec8af7f0 [12561.291461][ T8470] x29: e4ff000eec8af8b0 x28: 0dff000eec868ce0 [12561.297476][ T8470] x27: 0000000000000000 x26: 0400000000000001 [12561.303490][ T8470] x25: e4ff000eec8afa48 x24: ffff000eec8dffe8 [12561.309503][ T8470] x23: e4ff000eec8af80c x22: 0dff000eec868c30 [12561.315517][ T8470] x21: e4ff000eec8afa30 x20: 0000000000000000 [12561.321529][ T8470] x19: 0000000000100cca x18: 0000000000000000 [12561.327541][ T8470] x17: 0000000000000000 x16: 0000000000000000 [12561.333553][ T8470] x15: 0000000000000000 x14: 0000000000000000 [12561.339567][ T8470] x13: 0000000000000000 x12: 0000000000000000 [12561.345580][ T8470] x11: 00000000000000e4 x10: ffff8000eec8af82 [12561.351593][ T8470] x9 : ffff8000eec8af81 x8 : 0000000000000001 [12561.357605][ T8470] x7 : 0000000000000000 x6 : 0000000000000000 [12561.363617][ T8470] x5 : e4ff000eec8af848 x4 : e4ff000eec8af850 [12561.369630][ T8470] x3 : ffff90001042ec64 x2 : 0000000000000000 [12561.375648][ T8470] x1 : 0000000000000008 x0 : 0000000000000001 [12561.381679][ T8470] Call trace: [12561.384849][ T8470] swap_vma_readahead+0x360/0x568 [12561.389747][ T8470] swapin_readahead+0x9c/0xc0 [12561.394308][ T8470] do_swap_page+0x314/0xccc [12561.398684][ T8470] handle_pte_fault+0x7a0/0x14d0 [12561.403494][ T8470] handle_mm_fault+0x4ac/0x5d0 [12561.408143][ T8470] do_page_fault+0x45c/0x708 [12561.412626][ T8470] do_translation_fault+0x60/0x98 [12561.417535][ T8470] do_mem_abort+0x58/0xf4 [12561.421754][ T8470] el1_sync_handler+0x9c/0x100 [12561.426403][ T8470] el1_sync+0xb4/0x180 [12561.430360][ T8470] __arch_copy_from_user+0x24/0x240 [12561.435446][ T8470] __arm64_sys_recvmmsg+0xa0/0x1a8 [12561.440433][ T8470] do_el0_svc+0x128/0x1dc [12561.444641][ T8470] el0_sync_handler+0x150/0x250 [12561.449365][ T8470] el0_sync+0x164/0x180 [12561.453408][ T8470] Code: 6b08029f 54000842 aa1803e0 940101ef (f9400308) [12561.460883][ T8470] ---[ end trace d7b340909510bdcf ]--- [12561.466220][ T8470] Kernel panic - not syncing: Fatal exception [12561.472743][ T8470] SMP: stopping secondary CPUs [12561.477581][ T8470] Kernel Offset: disabled [12561.481770][ T8470] CPU features: 0x006002,61000c38 [12561.486648][ T8470] Memory Limit: none [12561.490729][ T8470] ---[ end Kernel panic - not syncing: Fatal exception ]--- > > [34944.838318][T48906] BUG: unable to handle page fault for address: ffff888cb196bfe8 > [34944.845970][T48906] #PF: supervisor read access in kernel mode > [34944.847199][T50168] futex_wake_op: trinity-c58 tries to shift op by -1; fix this program > [34944.851855][T48906] #PF: error_code(0x0000) - not-present page > [34944.851866][T48906] PGD f63401067 P4D f63401067 PUD 1079630067 PMD 10794a3067 PTE 800ffff34e694060 > [34944.874964][T48906] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI > [34944.881289][T48906] CPU: 72 PID: 48906 Comm: trinity-c85 Tainted: G L 5.7.0-rc1-next-20200414+ #8 > [34944.891559][T48906] Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 > [34944.900860][T48906] RIP: 0010:swapin_readahead+0x40a/0x85f > swap_vma_readahead at mm/swap_state.c:741 > (inlined by) swapin_readahead at mm/swap_state.c:785 > [34944.906394][T48906] Code: 6c 24 70 44 8b 64 24 0c 4c 89 6c 24 18 eb 13 41 83 c4 01 49 83 c6 08 44 3b 64 24 20 0f 84 38 03 00 00 4c 89 f7 e8 66 74 04 00 <4d> 8b 3e 49 f7 c7 9f ff ff ff 74 d9 48 c7 c7 a0 83 23 91 e8 4e 74 > [34944.925989][T48906] RSP: 0018:ffffc9002622f620 EFLAGS: 00010246 > [34944.931960][T48906] RAX: 0000000000000000 RBX: ffffc9002622f8d8 RCX: ffffffff902370aa > [34944.939849][T48906] RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff888cb196bfe8 > [34944.947737][T48906] RBP: ffffc9002622f758 R08: 0000000000000000 R09: ffffed112d8078e7 > [34944.955625][T48906] R10: ffff88896c03c737 R11: ffffed112d8078e6 R12: 0000000000000000 > [34944.963580][T48906] R13: ffffc9002622f690 R14: ffff888cb196bfe8 R15: ffff888cb196c000 > [34944.971479][T48906] FS: 00007f17c465a740(0000) GS:ffff889032c00000(0000) knlGS:0000000000000000 > [34944.980329][T48906] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [34944.986820][T48906] CR2: ffff888cb196bfe8 CR3: 0000000c17964000 CR4: 00000000003406e0 > [34944.994709][T48906] Call Trace: > [34944.997895][T48906] ? exit_swap_address_space+0x160/0x160 > [34945.003429][T48906] ? lookup_swap_cache+0x144/0x410 > [34945.008516][T48906] ? swapcache_prepare+0x20/0x20 > [34945.013352][T48906] do_swap_page+0x4ef/0xe70 > do_swap_page at mm/memory.c:3141 > [34945.017751][T48906] ? unmap_mapping_range+0x30/0x30 > [34945.022763][T48906] __handle_mm_fault+0xb80/0xbe0 > [34945.027601][T48906] ? copy_page_range+0x420/0x420 > [34945.032438][T48906] handle_mm_fault+0xdc/0x2e0 > [34945.037013][T48906] do_page_fault+0x2cb/0x9d7 > [34945.041607][T48906] page_fault+0x34/0x40 > [34945.045655][T48906] RIP: 0010:strncpy_from_user+0xc9/0x2a0 > [34945.051184][T48906] Code: 14 00 00 4c 01 e8 0f 92 c1 0f 82 45 01 00 00 48 39 c2 0f 82 3c 01 00 00 0f 01 cb 0f ae e8 49 83 fd 07 0f 86 b7 01 00 00 31 f6 <49> 8b 14 24 85 f6 0f 85 9b 01 00 00 49 8d 45 f8 4c 89 6d c0 49 89 > [34945.070775][T48906] RSP: 0018:ffffc9002622fb28 EFLAGS: 00050246 > [34945.076742][T48906] RAX: 0000000000000fe0 RBX: ffff888c17830040 RCX: 0000000000000000 > [34945.084626][T48906] RDX: 00007ffffffff000 RSI: 0000000000000000 RDI: ffff888c178314d0 > [34945.092516][T48906] RBP: ffffc9002622fb70 R08: 0000000000000fe0 R09: fffff940065ea9e1 > [34945.100402][T48906] R10: ffffea0032f54f07 R11: fffff940065ea9e0 R12: 0000000000000000 > [34945.108288][T48906] R13: 0000000000000fe0 R14: ffff888cbd53c060 R15: 0000000000000fe0 > [34945.116184][T48906] ? strncpy_from_user+0x96/0x2a0 > [34945.121106][T48906] getname_flags+0x6a/0x220 > [34945.125502][T48906] do_renameat2+0x17c/0x7e0 > [34945.129895][T48906] ? user_path_create+0x40/0x40 > [34945.134642][T48906] ? register_lock_class+0xb40/0xb40 > [34945.139824][T48906] ? match_held_lock+0x20/0x250 > [34945.144569][T48906] ? find_held_lock+0xca/0xf0 > [34945.149140][T48906] ? __kasan_check_read+0x11/0x20 > [34945.154062][T48906] ? perf_syscall_enter+0xf9/0x370 > [34945.159065][T48906] ? lock_downgrade+0x3e0/0x3e0 > [34945.163804][T48906] ? check_flags.part.28+0x86/0x220 > [34945.168896][T48906] ? rcu_read_lock_sched_held+0xac/0xe0 > [34945.174339][T48906] ? do_syscall_64+0x79/0xaf0 > [34945.178907][T48906] ? rcu_read_lock_bh_held+0xc0/0xc0 > [34945.184091][T48906] __x64_sys_rename+0x3b/0x50 > [34945.188659][T48906] do_syscall_64+0xcc/0xaf0 > [34945.193050][T48906] ? perf_call_bpf_enter+0x1a0/0x1a0 > [34945.198230][T48906] ? syscall_return_slowpath+0x580/0x580 > [34945.203760][T48906] ? entry_SYSCALL_64_after_hwframe+0x3e/0xb3 > [34945.209725][T48906] ? trace_hardirqs_off_caller+0x3a/0x150 > [34945.215340][T48906] ? trace_hardirqs_off_thunk+0x1a/0x1c > [34945.220780][T48906] entry_SYSCALL_64_after_hwframe+0x49/0xb3 > [34945.226568][T48906] RIP: 0033:0x7f17c3f5c839 > [34945.230872][T48906] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1f f6 2c 00 f7 d8 64 89 01 48 > [34945.250461][T48906] RSP: 002b:00007fff822be2d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 > [34945.258802][T48906] RAX: ffffffffffffffda RBX: 0000000000000052 RCX: 00007f17c3f5c839 > [34945.266685][T48906] RDX: 00000000000000e8 RSI: 0000000000000000 RDI: 0000000000000000 ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: linux-next: not-present page at swap_vma_readahead() 2020-04-14 21:22 ` Qian Cai @ 2020-04-15 2:01 ` Huang, Ying 2020-04-15 2:12 ` Qian Cai [not found] ` <20200616011334.GA815@lca.pw> 0 siblings, 2 replies; 9+ messages in thread From: Huang, Ying @ 2020-04-15 2:01 UTC (permalink / raw) To: Qian Cai; +Cc: Linux-MM, LKML, Minchan Kim, Hugh Dickins, Andrew Morton Qian Cai <cai@lca.pw> writes: >> On Apr 14, 2020, at 10:32 AM, Qian Cai <cai@lca.pw> wrote: >> >> Fuzzers are unhappy. Thoughts? > > This is rather to reproduce. All the traces so far are from copy_from_user() to trigger a page fault, > and then it dereferences a bad pte in swap_vma_readahead(), > > for (i = 0, pte = ra_info.ptes; i < ra_info.nr_pte; > i++, pte++) { > pentry = *pte; <— crashed here. > if (pte_none(pentry)) Is it possible to bisect this? Because the crash point is identified, it may be helpful to collect and analyze the status of the faulting page table and readahead ptes. But I am not familiar with the ARM64 architecture. So I cannot help much here. Best Regards, Huang, Ying ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: linux-next: not-present page at swap_vma_readahead() 2020-04-15 2:01 ` Huang, Ying @ 2020-04-15 2:12 ` Qian Cai 2020-04-15 8:54 ` Huang, Ying [not found] ` <20200616011334.GA815@lca.pw> 1 sibling, 1 reply; 9+ messages in thread From: Qian Cai @ 2020-04-15 2:12 UTC (permalink / raw) To: Huang, Ying; +Cc: Linux-MM, LKML, Minchan Kim, Hugh Dickins, Andrew Morton > On Apr 14, 2020, at 10:01 PM, Huang, Ying <ying.huang@intel.com> wrote: > > Is it possible to bisect this? Yes, I’ll need to find a quick reproducer first by analyzing the fuzzer’s last logs. > > Because the crash point is identified, it may be helpful to collect and > analyze the status of the faulting page table and readahead ptes. But I > am not familiar with the ARM64 architecture. So I cannot help much > here. It happens for x86 as well where the trace is in the first email of this thread. ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: linux-next: not-present page at swap_vma_readahead() 2020-04-15 2:12 ` Qian Cai @ 2020-04-15 8:54 ` Huang, Ying 2020-04-15 13:11 ` Qian Cai 0 siblings, 1 reply; 9+ messages in thread From: Huang, Ying @ 2020-04-15 8:54 UTC (permalink / raw) To: Qian Cai; +Cc: Linux-MM, LKML, Minchan Kim, Hugh Dickins, Andrew Morton Qian Cai <cai@lca.pw> writes: >> On Apr 14, 2020, at 10:01 PM, Huang, Ying <ying.huang@intel.com> wrote: >> >> Is it possible to bisect this? > > Yes, I’ll need to find a quick reproducer first by analyzing the fuzzer’s last logs. Can you share the reproducer to me when it's available? Or the command line you used to reproduce it now? >> >> Because the crash point is identified, it may be helpful to collect and >> analyze the status of the faulting page table and readahead ptes. But I >> am not familiar with the ARM64 architecture. So I cannot help much >> here. > > It happens for x86 as well where the trace is in the first email of this thread. Got it! Thanks! Best Regards, Huang, Ying ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: linux-next: not-present page at swap_vma_readahead() 2020-04-15 8:54 ` Huang, Ying @ 2020-04-15 13:11 ` Qian Cai 0 siblings, 0 replies; 9+ messages in thread From: Qian Cai @ 2020-04-15 13:11 UTC (permalink / raw) To: Huang, Ying; +Cc: Linux-MM, LKML, Minchan Kim, Hugh Dickins, Andrew Morton > On Apr 15, 2020, at 4:54 AM, Huang, Ying <ying.huang@intel.com> wrote: > > Qian Cai <cai@lca.pw> writes: > >>> On Apr 14, 2020, at 10:01 PM, Huang, Ying <ying.huang@intel.com> wrote: >>> >>> Is it possible to bisect this? >> >> Yes, I’ll need to find a quick reproducer first by analyzing the fuzzer’s last logs. > > Can you share the reproducer to me when it's available? Or the command > line you used to reproduce it now? Sure, the current reproducer is running a fuzzer inside a container, (It requires runc to be installed first.) https://raw.githubusercontent.com/cailca/linux-mm/master/runc.sh ^ permalink raw reply [flat|nested] 9+ messages in thread
[parent not found: <20200616011334.GA815@lca.pw>]
* RE: linux-next: not-present page at swap_vma_readahead() [not found] ` <20200616011334.GA815@lca.pw> @ 2020-07-20 0:37 ` Huang, Ying 2020-07-20 2:12 ` Qian Cai 0 siblings, 1 reply; 9+ messages in thread From: Huang, Ying @ 2020-07-20 0:37 UTC (permalink / raw) To: Qian Cai; +Cc: Linux-MM, LKML, Minchan Kim, Hugh Dickins, Andrew Morton [-- Attachment #1: Type: text/plain, Size: 5847 bytes --] Hi, Sorry for late reply. I found a problem in the swap readahead code. Can you help to check whether it can fix this? Best Regards, Huang, Ying ________________________________________ From: Qian Cai [cai@lca.pw] Sent: Tuesday, June 16, 2020 9:13 AM To: Huang, Ying Cc: Linux-MM; LKML; Minchan Kim; Hugh Dickins; Andrew Morton Subject: Re: linux-next: not-present page at swap_vma_readahead() On Wed, Apr 15, 2020 at 10:01:53AM +0800, Huang, Ying wrote: > Qian Cai <cai@lca.pw> writes: > > >> On Apr 14, 2020, at 10:32 AM, Qian Cai <cai@lca.pw> wrote: > >> > >> Fuzzers are unhappy. Thoughts? > > > > This is rather to reproduce. All the traces so far are from copy_from_user() to trigger a page fault, > > and then it dereferences a bad pte in swap_vma_readahead(), > > > > for (i = 0, pte = ra_info.ptes; i < ra_info.nr_pte; > > i++, pte++) { > > pentry = *pte; <— crashed here. > > if (pte_none(pentry)) > > Is it possible to bisect this? > > Because the crash point is identified, it may be helpful to collect and > analyze the status of the faulting page table and readahead ptes. But I > am not familiar with the ARM64 architecture. So I cannot help much > here. Ying, looks like the bug is still there today which manifests itself into a different form. Looking at the logs, I believe it was involved with swapoff(). Any other thought? I still have not found time to bisect this yet. [ 785.477183][ T8727] BUG: KASAN: slab-out-of-bounds in swapin_readahead+0x7b8/0xbc0 swap_vma_readahead at mm/swap_state.c:759 (inlined by) swapin_readahead at mm/swap_state.c:803 [ 785.484752][ T8727] Read of size 8 at addr ffff00886ecaffe8 by task trinity-c35/8727 [ 785.492488][ T8727] [ 785.494675][ T8727] CPU: 35 PID: 8727 Comm: trinity-c35 Not tainted 5.7.0-next-20200610 #3 [ 785.502942][ T8727] Hardware name: HPE Apollo 70 /C01_APACHE_MB , BIOS L50_5.13_1.11 06/18/2019 [ 785.513387][ T8727] Call trace: [ 785.516538][ T8727] dump_backtrace+0x0/0x398 [ 785.520891][ T8727] show_stack+0x14/0x20 [ 785.524900][ T8727] dump_stack+0x140/0x1b8 [ 785.529087][ T8727] print_address_description.isra.12+0x54/0x4a8 [ 785.535185][ T8727] kasan_report+0x134/0x1b8 [ 785.539545][ T8727] __asan_report_load8_noabort+0x2c/0x50 [ 785.545036][ T8727] swapin_readahead+0x7b8/0xbc0 [ 785.549745][ T8727] do_swap_page+0xb1c/0x19a0 [ 785.554195][ T8727] handle_mm_fault+0xf10/0x2b30 [ 785.558905][ T8727] do_page_fault+0x230/0x908 [ 785.563354][ T8727] do_translation_fault+0xe0/0x108 [ 785.568323][ T8727] do_mem_abort+0x64/0x180 [ 785.572597][ T8727] el1_sync_handler+0x188/0x1b8 [ 785.577305][ T8727] el1_sync+0x7c/0x100 [ 785.581232][ T8727] __arch_copy_to_user+0xc4/0x158 [ 785.586115][ T8727] __arm64_sys_sysinfo+0x2c/0xd0 [ 785.590912][ T8727] do_el0_svc+0x124/0x220 [ 785.595100][ T8727] el0_sync_handler+0x260/0x408 [ 785.599807][ T8727] el0_sync+0x140/0x180 [ 785.603818][ T8727] [ 785.606007][ T8727] Allocated by task 8673: [ 785.610193][ T8727] save_stack+0x24/0x50 [ 785.614208][ T8727] __kasan_kmalloc.isra.13+0xc4/0xe0 [ 785.619350][ T8727] kasan_slab_alloc+0x14/0x20 [ 785.623885][ T8727] slab_post_alloc_hook+0x50/0xa8 [ 785.628769][ T8727] kmem_cache_alloc+0x18c/0x438 [ 785.633479][ T8727] create_object+0x58/0x960 [ 785.637844][ T8727] kmemleak_alloc+0x2c/0x38 [ 785.642205][ T8727] slab_post_alloc_hook+0x70/0xa8 [ 785.647089][ T8727] kmem_cache_alloc_trace+0x178/0x308 [ 785.652322][ T8727] refill_pi_state_cache.part.10+0x3c/0x1a8 [ 785.658073][ T8727] futex_lock_pi+0x404/0x5e0 [ 785.662519][ T8727] do_futex+0x790/0x1448 [ 785.666618][ T8727] __arm64_sys_futex+0x204/0x588 [ 785.671411][ T8727] do_el0_svc+0x124/0x220 [ 785.675603][ T8727] el0_sync_handler+0x260/0x408 [ 785.680312][ T8727] el0_sync+0x140/0x180 [ 785.684322][ T8727] [ 785.686510][ T8727] Freed by task 0: [ 785.690088][ T8727] save_stack+0x24/0x50 [ 785.694104][ T8727] __kasan_slab_free+0x124/0x198 [ 785.698899][ T8727] kasan_slab_free+0x10/0x18 [ 785.703340][ T8727] slab_free_freelist_hook+0x110/0x298 [ 785.708648][ T8727] kmem_cache_free+0xc8/0x3e0 [ 785.713175][ T8727] free_object_rcu+0x1e0/0x3b8 [ 785.717796][ T8727] rcu_core+0x8bc/0xf40 [ 785.721810][ T8727] rcu_core_si+0xc/0x18 [ 785.725825][ T8727] efi_header_end+0x2d8/0x1204 [ 785.730442][ T8727] [ 785.732625][ T8727] The buggy address belongs to the object at ffff00886ecafd28 [ 785.732625][ T8727] which belongs to the cache kmemleak_object of size 368 [ 785.746875][ T8727] The buggy address is located 336 bytes to the right of [ 785.746875][ T8727] 368-byte region [ffff00886ecafd28, ffff00886ecafe98) [ 785.760519][ T8727] The buggy address belongs to the page: [ 785.766009][ T8727] page:ffffffe021fbb280 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff00886ecaa8c8 [ 785.776268][ T8727] flags: 0x7ffff800000200(slab) [ 785.780971][ T8727] raw: 007ffff800000200 ffffffe0222c12c8 ffffffe0223a1488 ffff000000323080 [ 785.789410][ T8727] raw: ffff00886ecaa8c8 00000000005b001d 00000001ffffffff 0000000000000000 [ 785.797849][ T8727] page dumped because: kasan: bad access85.811794][ T87270886ecaff00: fc fc fc fc fc fc ^ [ 785.842727] ffff00886ecb0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 785.858703][ T8727] ================================================================== [ 785.866621][ T8727] Disabling lock debugging due to kernel taint [ 785.872714][ T8727] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 785.879523][ T8727] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 785.886322][ T8727] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [-- Warning: decoded text below may be mangled, UTF-8 assumed --] [-- Attachment #2: 0001-dbg-Fix-a-logic-hole-in-swap_ra_info.patch --] [-- Type: text/x-patch; name="0001-dbg-Fix-a-logic-hole-in-swap_ra_info.patch", Size: 796 bytes --] From b6cad43ad3cf63d73e539e3eaadd4ec9d2744dc6 Mon Sep 17 00:00:00 2001 From: Huang Ying <ying.huang@intel.com> Date: Fri, 10 Jul 2020 17:27:45 +0800 Subject: [PATCH] dbg: Fix a logic hole in swap_ra_info() --- mm/swap_state.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/mm/swap_state.c b/mm/swap_state.c index 05889e8e3c97..8481c15829b2 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -669,12 +669,11 @@ static void swap_ra_info(struct vm_fault *vmf, pte_t *tpte; #endif + ra_info->win = 1; max_win = 1 << min_t(unsigned int, READ_ONCE(page_cluster), SWAP_RA_ORDER_CEILING); - if (max_win == 1) { - ra_info->win = 1; + if (max_win == 1) return; - } faddr = vmf->address; orig_pte = pte = pte_offset_map(vmf->pmd, faddr); -- 2.27.0 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: linux-next: not-present page at swap_vma_readahead() 2020-07-20 0:37 ` Huang, Ying @ 2020-07-20 2:12 ` Qian Cai 2020-07-20 3:32 ` Huang, Ying 0 siblings, 1 reply; 9+ messages in thread From: Qian Cai @ 2020-07-20 2:12 UTC (permalink / raw) To: Huang, Ying; +Cc: Linux-MM, LKML, Minchan Kim, Hugh Dickins, Andrew Morton On Mon, Jul 20, 2020 at 12:37:30AM +0000, Huang, Ying wrote: > Hi, > > Sorry for late reply. I found a problem in the swap readahead code. Can you help to check whether it can fix this? Unfortunately, I can still reproduce it easily after applied the patch. # git clone https://gitlab.com/cailca/linux-mm # git checkout v5.8-rc1 -- *.sh # dnf -y install tar wget golang libseccomp-devel jq # ./runc.sh [ 575.517290][T28667] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.522901][T28650] BUG: KASAN: slab-out-of-bounds in swapin_readahead+0x780/0xbd8 swap_vma_readahead at mm/swap_state.c:758 (inlined by) swapin_readahead at mm/swap_state.c:802 [ 575.522928][T28650] Read of size 8 at addr ffff0089a603ffe8 by task trinity-c92/28650 [ 575.522947][T28650] CPU: 126 PID: 28650 Comm: trinity-c92 Not tainted 5.8.0-rc5-next-20200717+ #1 [ 575.522958][T28650] Hardware name: HPE Apollo 70 /C01_APACHE_MB , BIOS L50_5.13_1.11 06/18/2019 [ 575.522966][T28650] Call trace: [ 575.529895][T28667] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.535819][T28590] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.535829][T28590] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.535836][T28590] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.537424][T28650] dump_backtrace+0x0/0x398 [ 575.537438][T28650] show_stack+0x14/0x20 [ 575.545308][T28667] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.554134][T28650] dump_stack+0x140/0x1c8 [ 575.554148][T28650] print_address_description.constprop.10+0x54/0x550 [ 575.554159][T28650] kasan_report+0x134/0x1b8 [ 575.554173][T28650] __asan_report_load8_noabort+0x2c/0x50 [ 575.559496][T28588] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.559506][T28588] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.559513][T28588] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.562203][T28586] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.562215][T28586] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.562223][T28586] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.665163][T28560] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.671260][T28650] swapin_readahead+0x780/0xbd8 [ 575.671280][T28650] do_swap_page+0xb1c/0x1a78 do_swap_page at mm/memory.c:3166 [ 575.678067][T28560] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.682774][T28650] handle_mm_fault+0xfd0/0x2c50 handle_pte_fault at mm/memory.c:4234 (inlined by) __handle_mm_fault at mm/memory.c:4368 (inlined by) handle_mm_fault at mm/memory.c:4466 [ 575.682789][T28650] do_page_fault+0x230/0x818 [ 575.682804][T28650] do_translation_fault+0x90/0xb0 [ 575.682819][T28650] do_mem_abort+0x64/0x180 [ 575.687259][T28560] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.694051][T28650] el1_sync_handler+0x188/0x1b8 [ 575.694064][T28650] el1_sync+0x7c/0x100 [ 575.694079][T28650] strncpy_from_user+0x270/0x3e8 [ 575.694100][T28650] getname_flags+0x80/0x330 [ 575.698001][T28827] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.698048][T28827] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.698056][T28827] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.755679][T28620] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.757304][T28650] user_path_at_empty+0x2c/0x60 [ 575.764131][T28620] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.768782][T28650] do_linkat+0x10c/0x528 [ 575.768792][T28650] __arm64_sys_linkat+0xa0/0xf8 [ 575.768802][T28650] do_el0_svc+0x124/0x228 [ 575.768812][T28650] el0_sync_handler+0x260/0x410 [ 575.768820][T28650] el0_sytack+0x24/0x50+0x14/0x20 [ 5ap file entry 58_object+0x58/0x968c/0x1880 [ 575.779790][T28650] __alloc_percpu_gfp+0x14/0x20 [ 575.779799][T28650] qdisc_alloc+0x2bc/0xb98 [ 575.779809][T28650] qdisc_create_dflt+0x60/0x748 [ 575.803406][T28643] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.806107][T28650] mq_init+0x1a0/0x3b8 [ 575.806120][T28650] qdisc_create_dflt+0xc8/0x748 [ 575.811321][T28643] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.815788][T28650] dev_activate+0x488/0x8b8 [ 575.815806][T28650] __dev_open+0x240/0x360 [ 575.820848][T28643] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.827542][T28650] __dev_change_flags+0x344/0x480 [ 575.827553][T28650] dev_change_flags+0x74/0x140 [ 575.906574][T28650] do_setlink+0x7c8/0x2760 [ 575.910856][T28650] __rtnl_newlink+0x80c/0x1000 [ 575.915481][T28650] rtnl_newlink+0x68/0xa0 [ 575.919671][T28650] rtnetlink_rcv_msg+0x394/0xa48 [ 575.924477][T28650] netlink_rcv_skb+0x19c/0x340 [ 575.929103][T28650] rtnetlink_rcv+0x14/0x20 [ 575.933380][T28650] netlink_unicast+0x3ec/0x5e0 [ 575.938005][T28650] netlink_sendmsg+0x63c/0xa60 [ 575.942632][T28650] ____sys_sendmsg+0x5b0/0x740 [ 575.947261][T28650] ___sys_sendmsg+0xec/0x160 [ 575.949053][T28716] futex_wake_op: trinity-c158 tries to shift op by -1; fix this program [ 575.951712][T28650] __sys_sendmsg+0xb8/0x130 [ 575.951727][T28650] __arm64_sys_sendmsg+0x6c/0x98 [ 575.969052][T28650] do_el0_svc+0x124/0x228 [ 575.973248][T28650] el0_sync_handler+0x260/0x410 [ 575.977959][T28650] el0_sync+0x140/0x180 [ 575.981974][T28650] Last call_rcu(): [ 575.985557][T28650] kasan_save_stack+0x24/0x50 [ 575.990099][T28650] kasan_record_aux_stack+0xe0/0x110 [ 575.995249][T28650] call_rcu+0x114/0x680 [ 575.999273][T28650] put_object+0x84/0xc0 [ 576.003303][T28650] __delete_object+0xc4/0x110 [ 576.007848][T28650] delete_object_full+0x18/0x20 [ 576.012565][T28650] kmemleak_free+0x2c/0x38 [ 576.016844][T28650] slab_free_freelist_hook+0x190/0x298 [ 576.022158][T28650] kmem_cache_free+0x128/0x518 [ 576.026775][T28650] file_free_rcu+0x68/0xb0 [ 576.031045][T28650] rcu_core+0x8b8/0xf90 [ 576.035059][T28650] rcu_core_si+0xc/0x18 [ 576.039079][T28650] efi_header_end+0x358/0x14d4 [ 576.043712][T28650] Second to last call_rcu(): [ 576.048176][T28650] kasan_save_stack+0x24/0x50 [ 576.052723][T28650] kasan_record_aux_stack+0xe0/0x110 [ 576.057871][T28650] call_rcu+0x114/0x680 [ 576.057998][T28976] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.061888][T28650] put_object+0x84/0xc0 [ 576.061898][T28650] __delete_object+0xc4/0x110 [ 576.061906][T28650] delete_object_full+0x18/0x20 [ 576.061917][T28650] kmemleak_free+0x2c/0x38 [ 576.061925][T28650] slab_free_freelist_hook+0x190/0x298 [ 576.061933][T28650] kmem_cache_free+0x128/0x518 [ 576.061950][T28650] putname+0xb8/0x108 [ 576.065453][T28678] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.065462][T28678] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.065470][T28678] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.068777][T28976] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.072740][T28650] do_sys_openat2+0x26c/0x4c0 [ 576.072753][T28650] do_sys_open+0xa4/0xf8 [ 576.077404][T28976] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.082097][T28650] __arm64_sys_openat+0x88/0xc8 [ 576.082107][T+0x260/0x410 [ 6.082138][T28650s to the cache kted 336 bytes to 576.082157][T28ntry 58025a5a5a5a5a5a [ 576.120513][T28650] page:00000000e119790b refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8a2603 [ 576.127826][T28675] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.131821][T28650] flags: 0x7ffff800000200(slab) [ 576.131835][T28650] raw: 007ffff800000200 ffffffe0223a3908 ffffffe02234c948 ffff000000322480 [ 576.131845][T28650] raw: 0000000000000000 00000000005b005b 00000001ffffffff 0000000000000000 [ 576.131853][T28650] page dumped because: kasan: bad access detected [ 576.131865][T28650] Memory state around the buggy address: [ 576.131875][T28650] ffff0089a603fe80: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc [ 576.131884][T28650] ffff0089a603ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 576.131894][T28650] >ffff0089a603ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 576.131900][T28650] ^ [ 576.131908][T28650] ffff0089a6040000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 576.131917][T28650] ffff0089a6040080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 576.131923][T28650] ================================================================== [ 576.131928][T28650] Disabling lock debugging due to kernel taint [ 576.132028][T28650] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.132038][T28650] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.132046][T28650] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.281114][T28912] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.286297][T28675] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.293442][T28912] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.293451][T28912] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a > From b6cad43ad3cf63d73e539e3eaadd4ec9d2744dc6 Mon Sep 17 00:00:00 2001 > From: Huang Ying <ying.huang@intel.com> > Date: Fri, 10 Jul 2020 17:27:45 +0800 > Subject: [PATCH] dbg: Fix a logic hole in swap_ra_info() > > --- > mm/swap_state.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/mm/swap_state.c b/mm/swap_state.c > index 05889e8e3c97..8481c15829b2 100644 > --- a/mm/swap_state.c > +++ b/mm/swap_state.c > @@ -669,12 +669,11 @@ static void swap_ra_info(struct vm_fault *vmf, > pte_t *tpte; > #endif > > + ra_info->win = 1; > max_win = 1 << min_t(unsigned int, READ_ONCE(page_cluster), > SWAP_RA_ORDER_CEILING); > - if (max_win == 1) { > - ra_info->win = 1; > + if (max_win == 1) > return; > - } > > faddr = vmf->address; > orig_pte = pte = pte_offset_map(vmf->pmd, faddr); > -- > 2.27.0 > ^ permalink raw reply [flat|nested] 9+ messages in thread
* RE: linux-next: not-present page at swap_vma_readahead() 2020-07-20 2:12 ` Qian Cai @ 2020-07-20 3:32 ` Huang, Ying 0 siblings, 0 replies; 9+ messages in thread From: Huang, Ying @ 2020-07-20 3:32 UTC (permalink / raw) To: Qian Cai; +Cc: Linux-MM, LKML, Minchan Kim, Hugh Dickins, Andrew Morton [-- Attachment #1: Type: text/plain, Size: 10667 bytes --] Thanks! Can you try the dbg patch attached? That will print more debugging information when abnormal PTE pointer is detected. Best Regards, Huang, Ying ________________________________________ From: Qian Cai [cai@lca.pw] Sent: Monday, July 20, 2020 10:12 AM To: Huang, Ying Cc: Linux-MM; LKML; Minchan Kim; Hugh Dickins; Andrew Morton Subject: Re: linux-next: not-present page at swap_vma_readahead() On Mon, Jul 20, 2020 at 12:37:30AM +0000, Huang, Ying wrote: > Hi, > > Sorry for late reply. I found a problem in the swap readahead code. Can you help to check whether it can fix this? Unfortunately, I can still reproduce it easily after applied the patch. # git clone https://gitlab.com/cailca/linux-mm # git checkout v5.8-rc1 -- *.sh # dnf -y install tar wget golang libseccomp-devel jq # ./runc.sh [ 575.517290][T28667] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.522901][T28650] BUG: KASAN: slab-out-of-bounds in swapin_readahead+0x780/0xbd8 swap_vma_readahead at mm/swap_state.c:758 (inlined by) swapin_readahead at mm/swap_state.c:802 [ 575.522928][T28650] Read of size 8 at addr ffff0089a603ffe8 by task trinity-c92/28650 [ 575.522947][T28650] CPU: 126 PID: 28650 Comm: trinity-c92 Not tainted 5.8.0-rc5-next-20200717+ #1 [ 575.522958][T28650] Hardware name: HPE Apollo 70 /C01_APACHE_MB , BIOS L50_5.13_1.11 06/18/2019 [ 575.522966][T28650] Call trace: [ 575.529895][T28667] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.535819][T28590] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.535829][T28590] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.535836][T28590] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.537424][T28650] dump_backtrace+0x0/0x398 [ 575.537438][T28650] show_stack+0x14/0x20 [ 575.545308][T28667] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.554134][T28650] dump_stack+0x140/0x1c8 [ 575.554148][T28650] print_address_description.constprop.10+0x54/0x550 [ 575.554159][T28650] kasan_report+0x134/0x1b8 [ 575.554173][T28650] __asan_report_load8_noabort+0x2c/0x50 [ 575.559496][T28588] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.559506][T28588] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.559513][T28588] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.562203][T28586] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.562215][T28586] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.562223][T28586] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.665163][T28560] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.671260][T28650] swapin_readahead+0x780/0xbd8 [ 575.671280][T28650] do_swap_page+0xb1c/0x1a78 do_swap_page at mm/memory.c:3166 [ 575.678067][T28560] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.682774][T28650] handle_mm_fault+0xfd0/0x2c50 handle_pte_fault at mm/memory.c:4234 (inlined by) __handle_mm_fault at mm/memory.c:4368 (inlined by) handle_mm_fault at mm/memory.c:4466 [ 575.682789][T28650] do_page_fault+0x230/0x818 [ 575.682804][T28650] do_translation_fault+0x90/0xb0 [ 575.682819][T28650] do_mem_abort+0x64/0x180 [ 575.687259][T28560] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.694051][T28650] el1_sync_handler+0x188/0x1b8 [ 575.694064][T28650] el1_sync+0x7c/0x100 [ 575.694079][T28650] strncpy_from_user+0x270/0x3e8 [ 575.694100][T28650] getname_flags+0x80/0x330 [ 575.698001][T28827] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.698048][T28827] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.698056][T28827] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.755679][T28620] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.757304][T28650] user_path_at_empty+0x2c/0x60 [ 575.764131][T28620] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.768782][T28650] do_linkat+0x10c/0x528 [ 575.768792][T28650] __arm64_sys_linkat+0xa0/0xf8 [ 575.768802][T28650] do_el0_svc+0x124/0x228 [ 575.768812][T28650] el0_sync_handler+0x260/0x410 [ 575.768820][T28650] el0_sytack+0x24/0x50+0x14/0x20 [ 5ap file entry 58_object+0x58/0x968c/0x1880 [ 575.779790][T28650] __alloc_percpu_gfp+0x14/0x20 [ 575.779799][T28650] qdisc_alloc+0x2bc/0xb98 [ 575.779809][T28650] qdisc_create_dflt+0x60/0x748 [ 575.803406][T28643] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.806107][T28650] mq_init+0x1a0/0x3b8 [ 575.806120][T28650] qdisc_create_dflt+0xc8/0x748 [ 575.811321][T28643] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.815788][T28650] dev_activate+0x488/0x8b8 [ 575.815806][T28650] __dev_open+0x240/0x360 [ 575.820848][T28643] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 575.827542][T28650] __dev_change_flags+0x344/0x480 [ 575.827553][T28650] dev_change_flags+0x74/0x140 [ 575.906574][T28650] do_setlink+0x7c8/0x2760 [ 575.910856][T28650] __rtnl_newlink+0x80c/0x1000 [ 575.915481][T28650] rtnl_newlink+0x68/0xa0 [ 575.919671][T28650] rtnetlink_rcv_msg+0x394/0xa48 [ 575.924477][T28650] netlink_rcv_skb+0x19c/0x340 [ 575.929103][T28650] rtnetlink_rcv+0x14/0x20 [ 575.933380][T28650] netlink_unicast+0x3ec/0x5e0 [ 575.938005][T28650] netlink_sendmsg+0x63c/0xa60 [ 575.942632][T28650] ____sys_sendmsg+0x5b0/0x740 [ 575.947261][T28650] ___sys_sendmsg+0xec/0x160 [ 575.949053][T28716] futex_wake_op: trinity-c158 tries to shift op by -1; fix this program [ 575.951712][T28650] __sys_sendmsg+0xb8/0x130 [ 575.951727][T28650] __arm64_sys_sendmsg+0x6c/0x98 [ 575.969052][T28650] do_el0_svc+0x124/0x228 [ 575.973248][T28650] el0_sync_handler+0x260/0x410 [ 575.977959][T28650] el0_sync+0x140/0x180 [ 575.981974][T28650] Last call_rcu(): [ 575.985557][T28650] kasan_save_stack+0x24/0x50 [ 575.990099][T28650] kasan_record_aux_stack+0xe0/0x110 [ 575.995249][T28650] call_rcu+0x114/0x680 [ 575.999273][T28650] put_object+0x84/0xc0 [ 576.003303][T28650] __delete_object+0xc4/0x110 [ 576.007848][T28650] delete_object_full+0x18/0x20 [ 576.012565][T28650] kmemleak_free+0x2c/0x38 [ 576.016844][T28650] slab_free_freelist_hook+0x190/0x298 [ 576.022158][T28650] kmem_cache_free+0x128/0x518 [ 576.026775][T28650] file_free_rcu+0x68/0xb0 [ 576.031045][T28650] rcu_core+0x8b8/0xf90 [ 576.035059][T28650] rcu_core_si+0xc/0x18 [ 576.039079][T28650] efi_header_end+0x358/0x14d4 [ 576.043712][T28650] Second to last call_rcu(): [ 576.048176][T28650] kasan_save_stack+0x24/0x50 [ 576.052723][T28650] kasan_record_aux_stack+0xe0/0x110 [ 576.057871][T28650] call_rcu+0x114/0x680 [ 576.057998][T28976] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.061888][T28650] put_object+0x84/0xc0 [ 576.061898][T28650] __delete_object+0xc4/0x110 [ 576.061906][T28650] delete_object_full+0x18/0x20 [ 576.061917][T28650] kmemleak_free+0x2c/0x38 [ 576.061925][T28650] slab_free_freelist_hook+0x190/0x298 [ 576.061933][T28650] kmem_cache_free+0x128/0x518 [ 576.061950][T28650] putname+0xb8/0x108 [ 576.065453][T28678] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.065462][T28678] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.065470][T28678] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.068777][T28976] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.072740][T28650] do_sys_openat2+0x26c/0x4c0 [ 576.072753][T28650] do_sys_open+0xa4/0xf8 [ 576.077404][T28976] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.082097][T28650] __arm64_sys_openat+0x88/0xc8 [ 576.082107][T+0x260/0x410 [ 6.082138][T28650s to the cache kted 336 bytes to 576.082157][T28ntry 58025a5a5a5a5a5a [ 576.120513][T28650] page:00000000e119790b refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8a2603 [ 576.127826][T28675] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.131821][T28650] flags: 0x7ffff800000200(slab) [ 576.131835][T28650] raw: 007ffff800000200 ffffffe0223a3908 ffffffe02234c948 ffff000000322480 [ 576.131845][T28650] raw: 0000000000000000 00000000005b005b 00000001ffffffff 0000000000000000 [ 576.131853][T28650] page dumped because: kasan: bad access detected [ 576.131865][T28650] Memory state around the buggy address: [ 576.131875][T28650] ffff0089a603fe80: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc [ 576.131884][T28650] ffff0089a603ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 576.131894][T28650] >ffff0089a603ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 576.131900][T28650] ^ [ 576.131908][T28650] ffff0089a6040000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 576.131917][T28650] ffff0089a6040080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 576.131923][T28650] ================================================================== [ 576.131928][T28650] Disabling lock debugging due to kernel taint [ 576.132028][T28650] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.132038][T28650] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.132046][T28650] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.281114][T28912] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.286297][T28675] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.293442][T28912] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a [ 576.293451][T28912] get_swap_device: Bad swap file entry 58025a5a5a5a5a5a > From b6cad43ad3cf63d73e539e3eaadd4ec9d2744dc6 Mon Sep 17 00:00:00 2001 > From: Huang Ying <ying.huang@intel.com> > Date: Fri, 10 Jul 2020 17:27:45 +0800 > Subject: [PATCH] dbg: Fix a logic hole in swap_ra_info() > > --- > mm/swap_state.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/mm/swap_state.c b/mm/swap_state.c > index 05889e8e3c97..8481c15829b2 100644 > --- a/mm/swap_state.c > +++ b/mm/swap_state.c > @@ -669,12 +669,11 @@ static void swap_ra_info(struct vm_fault *vmf, > pte_t *tpte; > #endif > > + ra_info->win = 1; > max_win = 1 << min_t(unsigned int, READ_ONCE(page_cluster), > SWAP_RA_ORDER_CEILING); > - if (max_win == 1) { > - ra_info->win = 1; > + if (max_win == 1) > return; > - } > > faddr = vmf->address; > orig_pte = pte = pte_offset_map(vmf->pmd, faddr); > -- > 2.27.0 > [-- Warning: decoded text below may be mangled, UTF-8 assumed --] [-- Attachment #2: 0001-dbg-dump-upon-abnormal-pte-values.patch --] [-- Type: text/x-patch; name="0001-dbg-dump-upon-abnormal-pte-values.patch", Size: 1029 bytes --] From 3ca7a9ba58541d8692d3f83cbded2ad17be23359 Mon Sep 17 00:00:00 2001 From: Huang Ying <ying.huang@intel.com> Date: Mon, 20 Jul 2020 11:29:38 +0800 Subject: [PATCH] dbg: dump upon abnormal pte values --- mm/swap_state.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/mm/swap_state.c b/mm/swap_state.c index 05889e8e3c97..c1973136d035 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -756,6 +756,17 @@ static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask, blk_start_plug(&plug); for (i = 0, pte = ra_info.ptes; i < ra_info.nr_pte; i++, pte++) { + pte_t *tpte = pte_offset_map(vmf->pmd, vmf->address); + + if (((unsigned long)pte >> PAGE_SHIFT) != + ((unsigned long)tpte >> PAGE_SHIFT)) { + pr_info("ra_info: %d, %d, %d, %p\n", + ra_info.win, ra_info.offset, ra_info.nr_pte, + ra_info.ptes); + pr_info("i: %d, pte: %p, faddr: %lx\n", i, pte, + vmf->address); + } + pte_unmap(tpte); pentry = *pte; if (pte_none(pentry)) continue; -- 2.27.0 ^ permalink raw reply related [flat|nested] 9+ messages in thread
end of thread, other threads:[~2020-07-20 3:33 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
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2020-04-14 14:32 linux-next: not-present page at swap_vma_readahead() Qian Cai
2020-04-14 21:22 ` Qian Cai
2020-04-15 2:01 ` Huang, Ying
2020-04-15 2:12 ` Qian Cai
2020-04-15 8:54 ` Huang, Ying
2020-04-15 13:11 ` Qian Cai
[not found] ` <20200616011334.GA815@lca.pw>
2020-07-20 0:37 ` Huang, Ying
2020-07-20 2:12 ` Qian Cai
2020-07-20 3:32 ` Huang, Ying
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