Re: [syzbot] [fs?] [mm?] WARNING in page_copy_sane
From: Sidhartha Kumar
Date: Mon Sep 18 2023 - 14:11:22 EST
On 9/17/23 11:41 PM, syzbot wrote:
Hello,
syzbot found the following issue on:
HEAD commit: 98897dc735cf Add linux-next specific files for 20230914
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1548728c680000
kernel config: https://syzkaller.appspot.com/x/.config?x=1502c503717ada5c
dashboard link: https://syzkaller.appspot.com/bug?extid=c225dea486da4d5592bd
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=171fffd8680000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17bbbf1c680000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/00e4c0af5a8a/disk-98897dc7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7b54a00eee56/vmlinux-98897dc7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/100094353b8e/bzImage-98897dc7.xz
The issue was bisected to:
commit 591a2520fbfd6565d9a5c732afa53f62228798e6
Author: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Date: Mon Sep 11 21:53:19 2023 +0000
mm/filemap: remove hugetlb special casing in filemap.c
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15e15464680000
final oops: https://syzkaller.appspot.com/x/report.txt?x=17e15464680000
console output: https://syzkaller.appspot.com/x/log.txt?x=13e15464680000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c225dea486da4d5592bd@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 591a2520fbfd ("mm/filemap: remove hugetlb special casing in filemap.c")
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5040 at lib/iov_iter.c:463 page_copy_sane+0xc2/0x2c0 lib/iov_iter.c:463
Modules linked in:
CPU: 1 PID: 5040 Comm: syz-executor204 Not tainted 6.6.0-rc1-next-20230914-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
RIP: 0010:page_copy_sane+0xc2/0x2c0 lib/iov_iter.c:463
Code: e8 73 db 63 fd 66 90 e8 6c db 63 fd e8 67 db 63 fd 4c 89 ee 48 89 ef e8 6c d6 63 fd 49 39 ed 0f 83 eb 00 00 00 e8 4e db 63 fd <0f> 0b 31 db e8 45 db 63 fd 89 d8 5b 5d 41 5c 41 5d 41 5e 41 5f c3
RSP: 0018:ffffc90003eefa58 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88807a01d940 RSI: ffffffff84241482 RDI: 0000000000000006
RBP: 0000000000200000 R08: 0000000000000006 R09: 0000000000201000
R10: 0000000000200000 R11: 0000000000000000 R12: 0000000000000009
R13: 0000000000201000 R14: 0000000000000001 R15: ffffea0001fe0000
FS: 0000555556937380(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200001c0 CR3: 000000002911d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
copy_page_to_iter+0x35/0x180 lib/iov_iter.c:472
hugetlbfs_read_iter+0x3d7/0xa60 fs/hugetlbfs/inode.c:385
call_read_iter include/linux/fs.h:1980 [inline]
do_iter_readv_writev+0x2f2/0x3c0 fs/read_write.c:733
do_iter_read+0x315/0x870 fs/read_write.c:795
vfs_readv+0x12d/0x1a0 fs/read_write.c:915
do_preadv fs/read_write.c:1007 [inline]
__do_sys_preadv fs/read_write.c:1057 [inline]
__se_sys_preadv fs/read_write.c:1052 [inline]
__x64_sys_preadv+0x228/0x300 fs/read_write.c:1052
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f85cc7932e9
Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffda50bbbd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00007ffda50bbdb8 RCX: 00007f85cc7932e9
RDX: 0000000000000002 RSI: 0000000020000180 RDI: 0000000000000003
RBP: 00007f85cc806610 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffda50bbda8 R14: 0000000000000001 R15: 0000000000000001
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
If the bug is already fixed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite bug's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the bug is a duplicate of another bug, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
#syz testFrom 37a6528d0dda934ce1d023cb7d8c9a3d2063b57e Mon Sep 17 00:00:00 2001
From: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Date: Mon, 18 Sep 2023 11:40:07 -0500
Subject: [PATCH] mm/hugetlb: fix warning in page_copy_sane
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
---
fs/hugetlbfs/inode.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 14d3d28e41b0..629dcd4856bf 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -334,7 +334,7 @@ static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
ssize_t retval = 0;
while (iov_iter_count(to)) {
- struct page *page;
+ struct folio *folio;
size_t nr, copied, want;
/* nr is the maximum number of bytes to copy from this page */
@@ -352,18 +352,18 @@ static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
}
nr = nr - offset;
- /* Find the page */
- page = find_lock_page(mapping, index);
- if (unlikely(page == NULL)) {
+ /* Find the folio */
+ folio = filemap_lock_hugetlb_folio(h, mapping, index);
+ if (unlikely(folio == NULL)) {
/*
* We have a HOLE, zero out the user-buffer for the
* length of the hole or request.
*/
copied = iov_iter_zero(nr, to);
} else {
- unlock_page(page);
+ folio_unlock(folio);
- if (!PageHWPoison(page))
+ if (!folio_test_has_hwpoisoned(folio))
want = nr;
else {
/*
@@ -371,9 +371,9 @@ static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
* touching the 1st raw HWPOISON subpage after
* offset.
*/
- want = adjust_range_hwpoison(page, offset, nr);
+ want = adjust_range_hwpoison(&folio->page, offset, nr);
if (want == 0) {
- put_page(page);
+ folio_put(folio);
retval = -EIO;
break;
}
@@ -382,8 +382,8 @@ static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
/*
* We have the page, copy it to user space buffer.
*/
- copied = copy_page_to_iter(page, offset, want, to);
- put_page(page);
+ copied = copy_page_to_iter(&folio->page, offset, want, to);
+ folio_put(folio);
}
offset += copied;
retval += copied;
--
2.41.0