[PATCH 2/2] mm/hugetlb: fix unable to handle page fault for address dead000000000108

[Miaohe Lin]

Below panic occurs when I did memory failure test:

BUG: unable to handle page fault for address: dead000000000108
PGD 0 P4D 0
Oops: Oops: 0001 [#1] PREEMPT SMP NOPTI
CPU: 0 PID: 1073 Comm: bash Not tainted 6.9.0-rc4-next-20240417-dirty #52
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
RIP: 0010:enqueue_hugetlb_folio+0x46/0xe0
RSP: 0018:ffff9e0207f03d10 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: dead000000000122
RDX: ffffcbb244460008 RSI: dead000000000100 RDI: ffff976a09da6f90
RBP: ffffcbb244460000 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: 7a088d6100000000 R12: ffffffffbcc93160
R13: 0000000000000246 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fdb749b1740(0000) GS:ffff97711fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: dead000000000108 CR3: 00000001078ac000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 free_huge_folio+0x28d/0x420
 dissolve_free_hugetlb_folio+0x135/0x1d0
 __page_handle_poison+0x18/0xb0
 memory_failure+0x712/0xd30
 hard_offline_page_store+0x55/0xa0
 kernfs_fop_write_iter+0x12c/0x1d0
 vfs_write+0x380/0x540
 ksys_write+0x64/0xe0
 do_syscall_64+0xbc/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdb74714887
RSP: 002b:00007ffdfc7074e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007fdb74714887
RDX: 000000000000000c RSI: 00005653ec7c0e10 RDI: 0000000000000001
RBP: 00005653ec7c0e10 R08: 00007fdb747d1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
R13: 00007fdb7481b780 R14: 00007fdb74817600 R15: 00007fdb74816a00
 </TASK>
Modules linked in: mce_inject hwpoison_inject
CR2: dead000000000108
---[ end trace 0000000000000000 ]---
RIP: 0010:enqueue_hugetlb_folio+0x46/0xe0
RSP: 0018:ffff9e0207f03d10 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: dead000000000122
RDX: ffffcbb244460008 RSI: dead000000000100 RDI: ffff976a09da6f90
RBP: ffffcbb244460000 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: 7a088d6100000000 R12: ffffffffbcc93160
R13: 0000000000000246 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fdb749b1740(0000) GS:ffff97711fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: dead000000000108 CR3: 00000001078ac000 CR4: 00000000000006f0
Kernel panic - not syncing: Fatal exception
Kernel Offset: 0x38a00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
---[ end Kernel panic - not syncing: Fatal exception ]---

The root cause is that list_del() is used to remove folio from list when
dissolve_free_hugetlb_folio(). But list_move() might be used to reenqueue
hugetlb folio when free_huge_folio() leading to above panic. Fix this
issue by using list_del_init() to remove folio.

Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
 mm/hugetlb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 1da9a14a5513..08634732dca4 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1642,7 +1642,7 @@ static void __remove_hugetlb_folio(struct hstate *h, struct folio *folio,
 	if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
 		return;
 
-	list_del(&folio->lru);
+	list_del_init(&folio->lru);
 
 	if (folio_test_hugetlb_freed(folio)) {
 		h->free_huge_pages--;
-- 
2.33.0