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(BJMBX02.spreadtrum.com [10.0.64.8]) by dlp.unisoc.com (SkyGuard) with ESMTPS id 4fPyF23QRxz2N7Y4c; Tue, 3 Mar 2026 09:01:58 +0800 (CST) Received: from BJMBX01.spreadtrum.com (10.0.64.7) by BJMBX02.spreadtrum.com (10.0.64.8) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Tue, 3 Mar 2026 09:02:55 +0800 Received: from BJMBX01.spreadtrum.com ([fe80::54e:9a:129d:fac7]) by BJMBX01.spreadtrum.com ([fe80::54e:9a:129d:fac7%16]) with mapi id 15.00.1497.048; Tue, 3 Mar 2026 09:02:55 +0800 From: =?utf-8?B?6buE5pyd6ZizIChaaGFveWFuZyBIdWFuZyk=?= To: syzbot ci , "akpm@linux-foundation.org" , "huangzhaoyang@gmail.com" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , =?utf-8?B?5bq357qq5ruoIChTdGV2ZSBLYW5nKQ==?= , "yuzhao@google.com" CC: "syzbot@lists.linux.dev" , "syzkaller-bugs@googlegroups.com" Subject: reply: [syzbot ci] Re: mm: bail out when the PMD has been set in bloom filter Thread-Topic: reply: [syzbot ci] Re: mm: bail out when the PMD has been set in bloom filter Thread-Index: AdyqpivCfGONClyQTxyiuGx6c5rhMQ== Date: Tue, 3 Mar 2026 01:02:54 +0000 Message-ID: <85f9e0cb6cc44a36b0ce624b6766ddc6@BJMBX01.spreadtrum.com> Accept-Language: zh-CN, en-US Content-Language: zh-CN X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MAIL: SHSQR01.spreadtrum.com 62312wlX042068 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=unisoc.com; s=default; t=1772499788; bh=1t/onS7jzftf/Zy0Y0jvNvAAfyka6oPianOa4p+o0n4=; h=From:To:CC:Subject:Date; b=Qze/a0x+OvkUMABdzRNR6KW+lSQBR4ygz5tBH58ydE61tVmtSQpCtFuyJYwEm3Hzg aRgN1RylaRSsETGoZlFDVQsTse87pbSBfuBR+y4aVrxMf6Btoi4zheyiv3xCObSfH3 c1yFyqKVxgjHeB34FSiNONZQmXqstxtW5NUEU1gv5wArgq1uJwsSmx7qqVsWpzNAsq 28zMiF8DhlI7J5Uy3QdO3EuHBjmpAcMMmY4TLlwFi8SK0b556DcYTS5lTjirlKQHc2 T1R/2PsfJVEIjOpEV4PmSb8AIK4SyPYk5Ag7snI+PX0aAZ5/5APXLEsBy4LcdWlPtj eYzl1BWJ6Xk1g== > > >syzbot ci has tested the following series > >[v1] mm: bail out when the PMD has been set in bloom filter >https://lore.kernel.org/all/20260227075250.1128175-1-zhaoyang.huang@uni >soc.com >* [PATCH] mm: bail out when the PMD has been set in bloom filter > >and found the following issue: >general protection fault in lru_gen_look_around > >Full report is available here: >https://ci.syzbot.org/series/78ce04ff-c36e-4bcc-a097-f457e3ed9e5e > >*** > >general protection fault in lru_gen_look_around > >tree: mm-new >URL: >https://kernel.googlesource.com/pub/scm/linux/kernel/git/akpm/mm.git >base: 8982358e1c87e3e1dc0aad37f4f93efe9c1cfe03 >arch: amd64 >compiler: Debian clang version 21.1.8 >(++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian >LLD 21.1.8 >config: >https://ci.syzbot.org/builds/e976d408-587c-416f-85ab-a60940674f35/config >C repro: >https://ci.syzbot.org/findings/ea92e1a7-69bd-4608-bc2c-2ff4ca118f9c/c_repr >o >syz repro: >https://ci.syzbot.org/findings/ea92e1a7-69bd-4608-bc2c-2ff4ca118f9c/syz_re >pro > >Oops: general protection fault, probably for non-canonical address >0xdffffc0000000003: 0000 [#1] SMP KASAN PTI >KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] >CPU: 1 UID: 0 PID: 5967 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(fu= ll) >Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS >1.16.2-debian-1.16.2-1 04/01/2014 >RIP: 0010:test_bloom_filter mm/vmscan.c:2785 [inline] >RIP: 0010:lru_gen_look_around+0x45c/0xd20 mm/vmscan.c:4206 >Code: 22 be ff 48 c7 44 24 48 00 00 00 00 48 83 c3 28 48 89 dd 48 c1 ed 03= 42 >80 7c 25 00 00 74 08 48 89 df e8 97 b5 28 00 4c 8b 3b <41> 80 7c 24 03 00 = 74 >0a bf 18 00 00 00 e8 82 b5 28 00 4c 8b 24 25 >RSP: 0018:ffffc900046e5c90 EFLAGS: 00010246 >RAX: 0000000000000000 RBX: ffffc900046e5e68 RCX: ffff8881100b1d00 >RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 >RBP: 1ffff920008dcbcd R08: ffff88811008fcc3 R09: 1ffff11022011f98 >R10: dffffc0000000000 R11: ffffed1022011f99 R12: dffffc0000000000 >R13: 0000555585af4000 R14: ffffea0006a69fc0 R15: ffff888114457168 >FS: 0000555585ad9500(0000) GS:ffff8882a9461000(0000) >knlGS:0000000000000000 >CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >CR2: 00007f4753817dac CR3: 00000001b9a5e000 CR4: 00000000000006f0 >Call Trace: > > folio_referenced_one+0x724/0x1360 mm/rmap.c:962 > rmap_walk_anon+0x5cb/0x7c0 mm/rmap.c:2973 rmap_walk >mm/rmap.c:3078 [inline] > folio_referenced+0x3c0/0x5f0 mm/rmap.c:1081 folio_check_references >mm/vmscan.c:870 [inline] > shrink_folio_list+0x1008/0x5240 mm/vmscan.c:1237 > evict_folios+0x3f82/0x5090 mm/vmscan.c:4853 > try_to_shrink_lruvec+0xb62/0xfa0 mm/vmscan.c:5008 >lru_gen_shrink_lruvec mm/vmscan.c:5157 [inline] > shrink_lruvec+0x54e/0x2b30 mm/vmscan.c:5911 shrink_node_memcgs >mm/vmscan.c:6147 [inline] > shrink_node+0xa41/0x3a90 mm/vmscan.c:6188 shrink_zones >mm/vmscan.c:6427 [inline] > do_try_to_free_pages+0x6a2/0x1980 mm/vmscan.c:6489 > try_to_free_mem_cgroup_pages+0x2ff/0x870 mm/vmscan.c:6811 > try_charge_memcg+0x827/0x1560 mm/memcontrol.c:2642 >obj_cgroup_charge_pages mm/memcontrol.c:3084 [inline] > __memcg_kmem_charge_page+0x32a/0x530 mm/memcontrol.c:3128 > __alloc_frozen_pages_noprof+0x1c1/0x380 mm/page_alloc.c:5271 >__alloc_pages_noprof mm/page_alloc.c:5288 [inline] > alloc_pages_bulk_noprof+0x569/0x710 mm/page_alloc.c:5208 > alloc_pages_bulk_mempolicy_noprof+0x34e/0x1680 mm/mempolicy.c:2792 >vm_area_alloc_pages mm/vmalloc.c:3700 [inline] __vmalloc_area_node >mm/vmalloc.c:3875 [inline] > __vmalloc_node_range_noprof+0xbd9/0x1a80 mm/vmalloc.c:4058 >__bpf_map_area_alloc kernel/bpf/syscall.c:404 [inline] > bpf_map_area_alloc+0x12d/0x170 kernel/bpf/syscall.c:411 > bloom_map_alloc+0x22f/0x470 kernel/bpf/bloom_filter.c:146 > map_create+0xafd/0x16a0 kernel/bpf/syscall.c:1507 > __sys_bpf+0x6e1/0x950 kernel/bpf/syscall.c:6210 __do_sys_bpf >kernel/bpf/syscall.c:6341 [inline] __se_sys_bpf kernel/bpf/syscall.c:6339 >[inline] > __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6339 > do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] > do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 >entry_SYSCALL_64_after_hwframe+0x77/0x7f >RIP: 0033:0x7f475359c799 >Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 >RSP: 002b:00007fff2e480d98 EFLAGS: 00000246 ORIG_RAX: >0000000000000141 >RAX: ffffffffffffffda RBX: 00007f4753815fa0 RCX: 00007f475359c799 >RDX: 0000000000000050 RSI: 0000200000000dc0 RDI: 0000000000000000 >RBP: 00007f4753632bd9 R08: 0000000000000000 R09: 0000000000000000 >R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 >R13: 00007f4753815fac R14: 00007f4753815fa0 R15: 00007f4753815fa0 > Modules linked in: >---[ end trace 0000000000000000 ]--- >RIP: 0010:test_bloom_filter mm/vmscan.c:2785 [inline] >RIP: 0010:lru_gen_look_around+0x45c/0xd20 mm/vmscan.c:4206 >Code: 22 be ff 48 c7 44 24 48 00 00 00 00 48 83 c3 28 48 89 dd 48 c1 ed 03= 42 >80 7c 25 00 00 74 08 48 89 df e8 97 b5 28 00 4c 8b 3b <41> 80 7c 24 03 00 = 74 >0a bf 18 00 00 00 e8 82 b5 28 00 4c 8b 24 25 >RSP: 0018:ffffc900046e5c90 EFLAGS: 00010246 >RAX: 0000000000000000 RBX: ffffc900046e5e68 RCX: ffff8881100b1d00 >RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 >RBP: 1ffff920008dcbcd R08: ffff88811008fcc3 R09: 1ffff11022011f98 >R10: dffffc0000000000 R11: ffffed1022011f99 R12: dffffc0000000000 >R13: 0000555585af4000 R14: ffffea0006a69fc0 R15: ffff888114457168 >FS: 0000555585ad9500(0000) GS:ffff8882a9461000(0000) >knlGS:0000000000000000 >CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >CR2: 00007f4753817dac CR3: 00000001b9a5e000 CR4: 00000000000006f0 >---------------- >Code disassembly (best guess): > 0: 22 be ff 48 c7 44 and 0x44c748ff(%rsi),%bh > 6: 24 48 and $0x48,%al > 8: 00 00 add %al,(%rax) > a: 00 00 add %al,(%rax) > c: 48 83 c3 28 add $0x28,%rbx > 10: 48 89 dd mov %rbx,%rbp > 13: 48 c1 ed 03 shr $0x3,%rbp > 17: 42 80 7c 25 00 00 cmpb $0x0,0x0(%rbp,%r12,1) > 1d: 74 08 je 0x27 > 1f: 48 89 df mov %rbx,%rdi > 22: e8 97 b5 28 00 call 0x28b5be > 27: 4c 8b 3b mov (%rbx),%r15 >* 2a: 41 80 7c 24 03 00 cmpb $0x0,0x3(%r12) <-- trapping >instruction > 30: 74 0a je 0x3c > 32: bf 18 00 00 00 mov $0x18,%edi > 37: e8 82 b5 28 00 call 0x28b5be > 3c: 4c rex.WR > 3d: 8b .byte 0x8b > 3e: 24 25 and $0x25,%al #syz test diff --git a/mm/vmscan.c b/mm/vmscan.c index fcf6b6f21eb9..5558a24d1564 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4235,7 +4235,7 @@ bool lru_gen_look_around(struct page_vma_mapped_walk = *pvmw) walk =3D current->reclaim_state ? current->reclaim_state->mm_walk := NULL; =20 /* may the pmd has been set in bloom filter */ - if (test_bloom_filter(mm_state, max_seq, pvmw->pmd)) + if (mm_state && test_bloom_filter(mm_state, max_seq, pvmw->pmd)) return true; =20 start =3D max(addr & PMD_MASK, vma->vm_start); > > >*** > >If these findings have caused you to resend the series or submit a separat= e fix, >please add the following tag to your commit message: > Tested-by: syzbot@syzkaller.appspotmail.com > >--- >This report is generated by a bot. It may contain errors. >syzbot ci engineers can be reached at syzkaller@googlegroups.com.