Re: [moderation/CI] Re: Use generic_file_read_iter() in hugetlbfs

#syz upstream

On Wed, Jul 15, 2026 at 10:24 AM syzbot ci
<[email protected]> wrote:
>
> syzbot ci has tested the following series
>
> [v3] Use generic_file_read_iter() in hugetlbfs
> https://lore.kernel.org/all/[email protected]
> * [PATCH v3 1/9] mm: Rename folio_contain_hwpoison_page() to folio_has_hwpoison_page()
> * [PATCH v3 2/9] hugetlb: Mark some function arguments as const
> * [PATCH v3 3/9] memory-failure: Track hugetlb poison in a hash table
> * [PATCH v3 4/9] mm: Handle hugetlb correctly in is_page_hwpoison()
> * [PATCH v3 5/9] filemap: Add hwpoison handling to filemap_read()
> * [PATCH v3 6/9] filemap: Remove checks in mapping_set_folio_order_range()
> * [PATCH v3 7/9] hugetlb: Set mapping folio order
> * [PATCH v3 8/9] filemap: Add support for authoritative mappings
> * [PATCH v3 9/9] hugetlb: replace hugetlbfs_read_iter() with generic_file_read_iter()
>
> and found the following issues:
> * BUG: unable to handle kernel NULL pointer dereference in filemap_read_folio
> * WARNING in bio_add_page
>
> Full report is available here:
> https://ci.syzbot.org/series/1ea7e79d-5597-441f-9992-9436608be7df
>
> ***
>
> BUG: unable to handle kernel NULL pointer dereference in filemap_read_folio
>
> tree:      mm-new
> URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/akpm/mm.git
> base:      0e35b9b6ec0ffcc5e23cbdec09f5c622ad532b53
> arch:      amd64
> compiler:  Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6
> config:    https://ci.syzbot.org/builds/75e70bfb-8622-4cc5-b17f-aece199fcf0c/config
> syz repro: https://ci.syzbot.org/findings/739ca35a-a1c0-4131-8e74-405498f14c31/syz_repro
>
> BUG: kernel NULL pointer dereference, address: 0000000000000000
> #PF: supervisor instruction fetch in kernel mode
> #PF: error_code(0x0010) - not-present page
> PGD 800000016c1bc067 P4D 800000016c1bc067 PUD 0
> Oops: Oops: 0010 [#1] SMP KASAN PTI
> CPU: 0 UID: 0 PID: 5815 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> RIP: 0010:0x0
> Code: Unable to access opcode bytes at 0xffffffffffffffd6.
> RSP: 0018:ffffc9000297ebf8 EFLAGS: 00010293
> RAX: ffffffff82063c39 RBX: 1ffff9200052fd84 RCX: ffff88816cc35940
> RDX: 0000000000000000 RSI: ffffea00047cf100 RDI: ffff888112445200
> RBP: ffffc9000297ecb0 R08: ffffea00047cf107 R09: 1ffffd40008f9e20
> R10: dffffc0000000000 R11: 0000000000000000 R12: 0000000000000000
> R13: 1ffffd40008f9e20 R14: ffffea00047cf100 R15: 1ffffd40008f9e21
> FS:  00007f7d325fe6c0(0000) GS:ffff88818dc0e000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: ffffffffffffffd6 CR3: 000000011311c000 CR4: 00000000000006f0
> Call Trace:
>  <TASK>
>  filemap_read_folio+0x12c/0x3a0 mm/filemap.c:2512
>  filemap_create_folio mm/filemap.c:2650 [inline]
>  filemap_get_pages+0xe9a/0x21e0 mm/filemap.c:2714
>  filemap_read+0x428/0x1730 mm/filemap.c:2841
>  __kernel_read+0x4ca/0x960 fs/read_write.c:532
>  integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28
>  ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:222 [inline]
>  ima_calc_file_hash+0x451/0x890 security/integrity/ima/ima_crypto.c:280
>  ima_collect_measurement+0x51b/0xa00 security/integrity/ima/ima_api.c:300
>  process_measurement+0x1272/0x1c10 security/integrity/ima/ima_main.c:425
>  ima_file_mmap+0x1b0/0x200 security/integrity/ima/ima_main.c:523
>  security_mmap_file+0x773/0xa20 security/security.c:2581
>  vm_mmap_pgoff+0x134/0x4e0 mm/util.c:575
>  ksys_mmap_pgoff+0x57d/0x760 mm/mmap.c:606
>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>  do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7f7d32f9ce59
> 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:00007f7d325fe028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
> RAX: ffffffffffffffda RBX: 00007f7d33215fa0 RCX: 00007f7d32f9ce59
> RDX: 0000000000000007 RSI: 0000000000003000 RDI: 0000200000000000
> RBP: 00007f7d33032e6f R08: ffffffffffffffff R09: 0000000000000000
> R10: 0000000000040033 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007f7d33216038 R14: 00007f7d33215fa0 R15: 00007ffc38aa2f18
>  </TASK>
> Modules linked in:
> CR2: 0000000000000000
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:0x0
> Code: Unable to access opcode bytes at 0xffffffffffffffd6.
> RSP: 0018:ffffc9000297ebf8 EFLAGS: 00010293
> RAX: ffffffff82063c39 RBX: 1ffff9200052fd84 RCX: ffff88816cc35940
> RDX: 0000000000000000 RSI: ffffea00047cf100 RDI: ffff888112445200
> RBP: ffffc9000297ecb0 R08: ffffea00047cf107 R09: 1ffffd40008f9e20
> R10: dffffc0000000000 R11: 0000000000000000 R12: 0000000000000000
> R13: 1ffffd40008f9e20 R14: ffffea00047cf100 R15: 1ffffd40008f9e21
> FS:  00007f7d325fe6c0(0000) GS:ffff88818dc0e000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: ffffffffffffffd6 CR3: 000000011311c000 CR4: 00000000000006f0
>
>
> ***
>
> WARNING in bio_add_page
>
> tree:      mm-new
> URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/akpm/mm.git
> base:      0e35b9b6ec0ffcc5e23cbdec09f5c622ad532b53
> arch:      amd64
> compiler:  Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6
> config:    https://ci.syzbot.org/builds/75e70bfb-8622-4cc5-b17f-aece199fcf0c/config
> syz repro: https://ci.syzbot.org/findings/a77d3cb3-6a99-45a3-bd83-722c3f7fcd2c/syz_repro
>
> ------------[ cut here ]------------
> len == 0
> WARNING: block/bio.c:1044 at bio_add_page+0x516/0x700 block/bio.c:1044, CPU#0: udevd/5627
> Modules linked in:
> CPU: 0 UID: 0 PID: 5627 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> RIP: 0010:bio_add_page+0x516/0x700 block/bio.c:1044
> Code: 31 ed 44 89 e8 48 83 c4 50 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 86 b2 30 fd 90 0f 0b 90 eb db e8 7b b2 30 fd 90 <0f> 0b 90 eb d0 e8 70 b2 30 fd 90 0f 0b 90 e9 76 fe ff ff e8 62 b2
> RSP: 0018:ffffc90004a0f0d8 EFLAGS: 00010293
> RAX: ffffffff8495b105 RBX: 0000000000000000 RCX: ffff88816d2c1dc0
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: 1ffff11020ef5792 R08: ffff8881077abcff R09: 1ffff11020ef579f
> R10: dffffc0000000000 R11: ffffed1020ef57a0 R12: ffff8881077abc94
> R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000
> FS:  00007f1740f39c80(0000) GS:ffff88818dc0e000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00005641bf6c0b88 CR3: 00000001bbfcc000 CR4: 00000000000006f0
> Call Trace:
>  <TASK>
>  bio_add_folio+0x64/0x90 block/bio.c:1099
>  do_mpage_readpage+0xd8c/0x1b40 fs/mpage.c:294
>  mpage_readahead+0x3e7/0x800 fs/mpage.c:370
>  read_pages+0x193/0x5a0 mm/readahead.c:174
>  page_cache_ra_unbounded+0x754/0x9d0 mm/readahead.c:315
>  do_page_cache_ra mm/readahead.c:348 [inline]
>  force_page_cache_ra+0x26c/0x2e0 mm/readahead.c:378
>  filemap_get_pages+0x560/0x21e0 mm/filemap.c:2708
>  filemap_read+0x428/0x1730 mm/filemap.c:2841
>  blkdev_read_iter+0x2f1/0x420 block/fops.c:830
>  new_sync_read fs/read_write.c:493 [inline]
>  vfs_read+0x595/0xa80 fs/read_write.c:574
>  ksys_read+0x150/0x270 fs/read_write.c:716
>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>  do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7f1740b16b6a
> Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83
> RSP: 002b:00007ffe51f09b58 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1740b16b6a
> RDX: 0000000000000400 RSI: 00005641bf68db38 RDI: 0000000000000009
> RBP: 0000000000000400 R08: 00005641bf68db10 R09: 0000000000000008
> R10: 0000000000000051 R11: 0000000000000246 R12: 00005641bf68db10
> R13: 00005641bf68db28 R14: 00005641bf690128 R15: 00005641bf6900d0
>  </TASK>
>
>
> ***
>
> If these findings have caused you to resend the series or submit a
> separate fix, please add the following tag to your commit message:
>   Tested-by: [email protected]
>
> ---
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