Messages in this thread | | | Subject | Re: list corruption in deferred_split_scan() | From | Yang Shi <> | Date | Mon, 15 Jul 2019 17:22:00 -0700 |
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On 7/15/19 2:23 PM, Qian Cai wrote: > On Fri, 2019-07-12 at 12:12 -0700, Yang Shi wrote: >>> Another possible lead is that without reverting the those commits below, >>> kdump >>> kernel would always also crash in shrink_slab_memcg() at this line, >>> >>> map = rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_map, true); >> This looks a little bit weird. It seems nodeinfo[nid] is NULL? I didn't >> think of where nodeinfo was freed but memcg was still online. Maybe a >> check is needed: > Actually, "memcg" is NULL.
It sounds weird. shrink_slab() is called in mem_cgroup_iter which does pin the memcg. So, the memcg should not go away.
> >> diff --git a/mm/vmscan.c b/mm/vmscan.c >> index a0301ed..bacda49 100644 >> --- a/mm/vmscan.c >> +++ b/mm/vmscan.c >> @@ -602,6 +602,9 @@ static unsigned long shrink_slab_memcg(gfp_t >> gfp_mask, int nid, >> if (!mem_cgroup_online(memcg)) >> return 0; >> >> + if (!memcg->nodeinfo[nid]) >> + return 0; >> + >> if (!down_read_trylock(&shrinker_rwsem)) >> return 0; >> >>> [ 9.072036][ T1] BUG: KASAN: null-ptr-deref in shrink_slab+0x111/0x440 >>> [ 9.072036][ T1] Read of size 8 at addr 0000000000000dc8 by task >>> swapper/0/1 >>> [ 9.072036][ T1] >>> [ 9.072036][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.0-next- >>> 20190711+ #10 >>> [ 9.072036][ T1] Hardware name: HPE ProLiant DL385 Gen10/ProLiant >>> DL385 >>> Gen10, BIOS A40 01/25/2019 >>> [ 9.072036][ T1] Call Trace: >>> [ 9.072036][ T1] dump_stack+0x62/0x9a >>> [ 9.072036][ T1] __kasan_report.cold.4+0xb0/0xb4 >>> [ 9.072036][ T1] ? unwind_get_return_address+0x40/0x50 >>> [ 9.072036][ T1] ? shrink_slab+0x111/0x440 >>> [ 9.072036][ T1] kasan_report+0xc/0xe >>> [ 9.072036][ T1] __asan_load8+0x71/0xa0 >>> [ 9.072036][ T1] shrink_slab+0x111/0x440 >>> [ 9.072036][ T1] ? mem_cgroup_iter+0x98/0x840 >>> [ 9.072036][ T1] ? unregister_shrinker+0x110/0x110 >>> [ 9.072036][ T1] ? kasan_check_read+0x11/0x20 >>> [ 9.072036][ T1] ? mem_cgroup_protected+0x39/0x260 >>> [ 9.072036][ T1] shrink_node+0x31e/0xa30 >>> [ 9.072036][ T1] ? shrink_node_memcg+0x1560/0x1560 >>> [ 9.072036][ T1] ? ktime_get+0x93/0x110 >>> [ 9.072036][ T1] do_try_to_free_pages+0x22f/0x820 >>> [ 9.072036][ T1] ? shrink_node+0xa30/0xa30 >>> [ 9.072036][ T1] ? kasan_check_read+0x11/0x20 >>> [ 9.072036][ T1] ? check_chain_key+0x1df/0x2e0 >>> [ 9.072036][ T1] try_to_free_pages+0x242/0x4d0 >>> [ 9.072036][ T1] ? do_try_to_free_pages+0x820/0x820 >>> [ 9.072036][ T1] __alloc_pages_nodemask+0x9ce/0x1bc0 >>> [ 9.072036][ T1] ? gfp_pfmemalloc_allowed+0xc0/0xc0 >>> [ 9.072036][ T1] ? unwind_dump+0x260/0x260 >>> [ 9.072036][ T1] ? kernel_text_address+0x33/0xc0 >>> [ 9.072036][ T1] ? arch_stack_walk+0x8f/0xf0 >>> [ 9.072036][ T1] ? ret_from_fork+0x22/0x40 >>> [ 9.072036][ T1] alloc_page_interleave+0x18/0x130 >>> [ 9.072036][ T1] alloc_pages_current+0xf6/0x110 >>> [ 9.072036][ T1] allocate_slab+0x600/0x11f0 >>> [ 9.072036][ T1] new_slab+0x46/0x70 >>> [ 9.072036][ T1] ___slab_alloc+0x5d4/0x9c0 >>> [ 9.072036][ T1] ? create_object+0x3a/0x3e0 >>> [ 9.072036][ T1] ? fs_reclaim_acquire.part.15+0x5/0x30 >>> [ 9.072036][ T1] ? ___might_sleep+0xab/0xc0 >>> [ 9.072036][ T1] ? create_object+0x3a/0x3e0 >>> [ 9.072036][ T1] __slab_alloc+0x12/0x20 >>> [ 9.072036][ T1] ? __slab_alloc+0x12/0x20 >>> [ 9.072036][ T1] kmem_cache_alloc+0x32a/0x400 >>> [ 9.072036][ T1] create_object+0x3a/0x3e0 >>> [ 9.072036][ T1] kmemleak_alloc+0x71/0xa0 >>> [ 9.072036][ T1] kmem_cache_alloc+0x272/0x400 >>> [ 9.072036][ T1] ? kasan_check_read+0x11/0x20 >>> [ 9.072036][ T1] ? do_raw_spin_unlock+0xa8/0x140 >>> [ 9.072036][ T1] acpi_ps_alloc_op+0x76/0x122 >>> [ 9.072036][ T1] acpi_ds_execute_arguments+0x2f/0x18d >>> [ 9.072036][ T1] acpi_ds_get_package_arguments+0x7d/0x84 >>> [ 9.072036][ T1] acpi_ns_init_one_package+0x33/0x61 >>> [ 9.072036][ T1] acpi_ns_init_one_object+0xfc/0x189 >>> [ 9.072036][ T1] acpi_ns_walk_namespace+0x114/0x1f2 >>> [ 9.072036][ T1] ? acpi_ns_init_one_package+0x61/0x61 >>> [ 9.072036][ T1] ? acpi_ns_init_one_package+0x61/0x61 >>> [ 9.072036][ T1] acpi_walk_namespace+0x9e/0xcb >>> [ 9.072036][ T1] ? acpi_sleep_proc_init+0x36/0x36 >>> [ 9.072036][ T1] acpi_ns_initialize_objects+0x99/0xed >>> [ 9.072036][ T1] ? acpi_ns_find_ini_methods+0xa2/0xa2 >>> [ 9.072036][ T1] ? acpi_tb_load_namespace+0x2dc/0x2eb >>> [ 9.072036][ T1] acpi_load_tables+0x61/0x80 >>> [ 9.072036][ T1] acpi_init+0x10d/0x44b >>> [ 9.072036][ T1] ? acpi_sleep_proc_init+0x36/0x36 >>> [ 9.072036][ T1] ? bus_uevent_filter+0x16/0x30 >>> [ 9.072036][ T1] ? kobject_uevent_env+0x109/0x980 >>> [ 9.072036][ T1] ? kernfs_get+0x13/0x20 >>> [ 9.072036][ T1] ? kobject_uevent+0xb/0x10 >>> [ 9.072036][ T1] ? kset_register+0x31/0x50 >>> [ 9.072036][ T1] ? kset_create_and_add+0x9f/0xd0 >>> [ 9.072036][ T1] ? acpi_sleep_proc_init+0x36/0x36 >>> [ 9.072036][ T1] do_one_initcall+0xfe/0x45a >>> [ 9.072036][ T1] ? initcall_blacklisted+0x150/0x150 >>> [ 9.072036][ T1] ? rwsem_down_read_slowpath+0x930/0x930 >>> [ 9.072036][ T1] ? kasan_check_write+0x14/0x20 >>> [ 9.072036][ T1] ? up_write+0x6b/0x190 >>> [ 9.072036][ T1] kernel_init_freeable+0x614/0x6a7 >>> [ 9.072036][ T1] ? rest_init+0x188/0x188 >>> [ 9.072036][ T1] kernel_init+0x11/0x138 >>> [ 9.072036][ T1] ? rest_init+0x188/0x188 >>> [ 9.072036][ T1] ret_from_fork+0x22/0x40 >>> [ 9.072036][ T1] >>> ================================================================== >>> [ 9.072036][ T1] Disabling lock debugging due to kernel taint >>> [ 9.145712][ T1] BUG: kernel NULL pointer dereference, address: >>> 0000000000000dc8 >>> [ 9.152036][ T1] #PF: supervisor read access in kernel mode >>> [ 9.152036][ T1] #PF: error_code(0x0000) - not-present page >>> [ 9.152036][ T1] PGD 0 P4D 0 >>> [ 9.152036][ T1] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI >>> [ 9.152036][ T1] CPU: 0 PID: 1 Comm: swapper/0 Tainted: >>> G B 5.2.0-next-20190711+ #10 >>> [ 9.152036][ T1] Hardware name: HPE ProLiant DL385 Gen10/ProLiant >>> DL385 >>> Gen10, BIOS A40 01/25/2019 >>> [ 9.152036][ T1] RIP: 0010:shrink_slab+0x111/0x440 >>> [ 9.152036][ T1] Code: c7 20 8d 44 82 e8 7f 8b e8 ff 85 c0 0f 84 e2 02 >>> 00 >>> 00 4c 63 a5 4c ff ff ff 49 81 c4 b8 01 00 00 4b 8d 7c e6 08 e8 3f 07 0e 00 >>> <4f> >>> 8b 64 e6 08 49 8d bc 24 20 03 00 00 e8 2d 07 0e 00 49 8b 84 24 >>> [ 9.152036][ T1] RSP: 0018:ffff88905757f100 EFLAGS: 00010282 >>> [ 9.152036][ T1] RAX: 0000000000000000 RBX: ffff88905757f1b0 RCX: >>> ffffffff8112f288 >>> [ 9.152036][ T1] RDX: 1ffffffff049c088 RSI: dffffc0000000000 RDI: >>> ffffffff824e0440 >>> [ 9.152036][ T1] RBP: ffff88905757f1d8 R08: fffffbfff049c089 R09: >>> fffffbfff049c088 >>> [ 9.152036][ T1] R10: fffffbfff049c088 R11: ffffffff824e0443 R12: >>> 00000000000001b8 >>> [ 9.152036][ T1] R13: 0000000000000000 R14: 0000000000000000 R15: >>> ffff88905757f440 >>> [ 9.152036][ T1] FS: 0000000000000000(0000) GS:ffff889062800000(0000) >>> knlGS:0000000000000000 >>> [ 9.152036][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>> [ 9.152036][ T1] CR2: 0000000000000dc8 CR3: 0000001070212000 CR4: >>> 00000000001406b0 >>> [ 9.152036][ T1] Call Trace: >>> [ 9.152036][ T1] ? mem_cgroup_iter+0x98/0x840 >>> [ 9.152036][ T1] ? unregister_shrinker+0x110/0x110 >>> [ 9.152036][ T1] ? kasan_check_read+0x11/0x20 >>> [ 9.152036][ T1] ? mem_cgroup_protected+0x39/0x260 >>> [ 9.152036][ T1] shrink_node+0x31e/0xa30 >>> [ 9.152036][ T1] ? shrink_node_memcg+0x1560/0x1560 >>> [ 9.152036][ T1] ? ktime_get+0x93/0x110 >>> [ 9.152036][ T1] do_try_to_free_pages+0x22f/0x820 >>> [ 9.152036][ T1] ? shrink_node+0xa30/0xa30 >>> [ 9.152036][ T1] ? kasan_check_read+0x11/0x20 >>> [ 9.152036][ T1] ? check_chain_key+0x1df/0x2e0 >>> [ 9.152036][ T1] try_to_free_pages+0x242/0x4d0 >>> [ 9.152036][ T1] ? do_try_to_free_pages+0x820/0x820 >>> [ 9.152036][ T1] __alloc_pages_nodemask+0x9ce/0x1bc0 >>> [ 9.152036][ T1] ? gfp_pfmemalloc_allowed+0xc0/0xc0 >>> [ 9.152036][ T1] ? unwind_dump+0x260/0x260 >>> [ 9.152036][ T1] ? kernel_text_address+0x33/0xc0 >>> [ 9.152036][ T1] ? arch_stack_walk+0x8f/0xf0 >>> [ 9.152036][ T1] ? ret_from_fork+0x22/0x40 >>> [ 9.152036][ T1] alloc_page_interleave+0x18/0x130 >>> [ 9.152036][ T1] alloc_pages_current+0xf6/0x110 >>> [ 9.152036][ T1] allocate_slab+0x600/0x11f0 >>> [ 9.152036][ T1] new_slab+0x46/0x70 >>> [ 9.152036][ T1] ___slab_alloc+0x5d4/0x9c0 >>> [ 9.152036][ T1] ? create_object+0x3a/0x3e0 >>> [ 9.152036][ T1] ? fs_reclaim_acquire.part.15+0x5/0x30 >>> [ 9.152036][ T1] ? ___might_sleep+0xab/0xc0 >>> [ 9.152036][ T1] ? create_object+0x3a/0x3e0 >>> [ 9.152036][ T1] __slab_alloc+0x12/0x20 >>> [ 9.152036][ T1] ? __slab_alloc+0x12/0x20 >>> [ 9.152036][ T1] kmem_cache_alloc+0x32a/0x400 >>> [ 9.152036][ T1] create_object+0x3a/0x3e0 >>> [ 9.152036][ T1] kmemleak_alloc+0x71/0xa0 >>> [ 9.152036][ T1] kmem_cache_alloc+0x272/0x400 >>> [ 9.152036][ T1] ? kasan_check_read+0x11/0x20 >>> [ 9.152036][ T1] ? do_raw_spin_unlock+0xa8/0x140 >>> [ 9.152036][ T1] acpi_ps_alloc_op+0x76/0x122 >>> [ 9.152036][ T1] acpi_ds_execute_arguments+0x2f/0x18d >>> [ 9.152036][ T1] acpi_ds_get_package_arguments+0x7d/0x84 >>> [ 9.152036][ T1] acpi_ns_init_one_package+0x33/0x61 >>> [ 9.152036][ T1] acpi_ns_init_one_object+0xfc/0x189 >>> [ 9.152036][ T1] acpi_ns_walk_namespace+0x114/0x1f2 >>> [ 9.152036][ T1] ? acpi_ns_init_one_package+0x61/0x61 >>> [ 9.152036][ T1] ? acpi_ns_init_one_package+0x61/0x61 >>> [ 9.152036][ T1] acpi_walk_namespace+0x9e/0xcb >>> [ 9.152036][ T1] ? acpi_sleep_proc_init+0x36/0x36 >>> [ 9.152036][ T1] acpi_ns_initialize_objects+0x99/0xed >>> [ 9.152036][ T1] ? acpi_ns_find_ini_methods+0xa2/0xa2 >>> [ 9.152036][ T1] ? acpi_tb_load_namespace+0x2dc/0x2eb >>> [ 9.152036][ T1] acpi_load_tables+0x61/0x80 >>> [ 9.152036][ T1] acpi_init+0x10d/0x44b >>> [ 9.152036][ T1] ? acpi_sleep_proc_init+0x36/0x36 >>> [ 9.152036][ T1] ? bus_uevent_filter+0x16/0x30 >>> [ 9.152036][ T1] ? kobject_uevent_env+0x109/0x980 >>> [ 9.152036][ T1] ? kernfs_get+0x13/0x20 >>> [ 9.152036][ T1] ? kobject_uevent+0xb/0x10 >>> [ 9.152036][ T1] ? kset_register+0x31/0x50 >>> [ 9.152036][ T1] ? kset_create_and_add+0x9f/0xd0 >>> [ 9.152036][ T1] ? acpi_sleep_proc_init+0x36/0x36 >>> [ 9.152036][ T1] do_one_initcall+0xfe/0x45a >>> [ 9.152036][ T1] ? initcall_blacklisted+0x150/0x150 >>> [ 9.152036][ T1] ? rwsem_down_read_slowpath+0x930/0x930 >>> [ 9.152036][ T1] ? kasan_check_write+0x14/0x20 >>> [ 9.152036][ T1] ? up_write+0x6b/0x190 >>> [ 9.152036][ T1] kernel_init_freeable+0x614/0x6a7 >>> [ 9.152036][ T1] ? rest_init+0x188/0x188 >>> [ 9.152036][ T1] kernel_init+0x11/0x138 >>> [ 9.152036][ T1] ? rest_init+0x188/0x188 >>> [ 9.152036][ T1] ret_from_fork+0x22/0x40 >>> [ 9.152036][ T1] Modules linked in: >>> [ 9.152036][ T1] CR2: 0000000000000dc8 >>> [ 9.152036][ T1] ---[ end trace 568acce4eca01945 ]--- >>> [ 9.152036][ T1] RIP: 0010:shrink_slab+0x111/0x440 >>> [ 9.152036][ T1] Code: c7 20 8d 44 82 e8 7f 8b e8 ff 85 c0 0f 84 e2 02 >>> 00 >>> 00 4c 63 a5 4c ff ff ff 49 81 c4 b8 01 00 00 4b 8d 7c e6 08 e8 3f 07 0e 00 >>> <4f> >>> 8b 64 e6 08 49 8d bc 24 20 03 00 00 e8 2d 07 0e 00 49 8b 84 24 >>> [ 9.152036][ T1] RSP: 0018:ffff88905757f100 EFLAGS: 00010282 >>> [ 9.152036][ T1] RAX: 0000000000000000 RBX: ffff88905757f1b0 RCX: >>> ffffffff8112f288 >>> [ 9.152036][ T1] RDX: 1ffffffff049c088 RSI: dffffc0000000000 RDI: >>> ffffffff824e0440 >>> [ 9.152036][ T1] RBP: ffff88905757f1d8 R08: fffffbfff049c089 R09: >>> fffffbfff049c088 >>> [ 9.152036][ T1] R10: fffffbfff049c088 R11: ffffffff824e0443 R12: >>> 00000000000001b8 >>> [ 9.152036][ T1] R13: 0000000000000000 R14: 0000000000000000 R15: >>> ffff88905757f440 >>> [ 9.152036][ T1] FS: 0000000000000000(0000) GS:ffff889062800000(0000) >>> knlGS:00000000 >>>
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