Re: [syzbot] [iomap?] kernel BUG in folio_end_read (2)

syzbot
2025-11-01T02:11:29Z

syzbot has found a reproducer for the following issue on:

HEAD commit: 98bd8b16ae57 Add linux-next specific files for 20251031
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=163b2bcd980000
kernel config: https://syzkaller.appspot.com/x/.config?x=63d09725c93bcc1c
dashboard link: https://syzkaller.appspot.com/bug?extid=3686758660f980b402dc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=176fc342580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10403f34580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/975261746f29/disk-98bd8b16.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ad565c6cf272/vmlinux-98bd8b16.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1816a55a8d5f/bzImage-98bd8b16.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/d6d9eee31fdb/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=17803f34580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3686758660f980b402dc@syzkaller.appspotmail.com

vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1279
do_vmi_align_munmap+0x364/0x440 mm/vma.c:1538
do_vmi_munmap+0x253/0x2e0 mm/vma.c:1586
__vm_munmap+0x207/0x380 mm/vma.c:3196
__do_sys_munmap mm/mmap.c:1077 [inline]
__se_sys_munmap mm/mmap.c:1074 [inline]
__x64_sys_munmap+0x60/0x70 mm/mmap.c:1074
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
------------[ cut here ]------------
kernel BUG at mm/filemap.c:1530!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 5989 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:folio_end_read+0x1e9/0x230 mm/filemap.c:1530
Code: 79 c7 ff 48 89 df 48 c7 c6 20 6d 74 8b e8 9f df 2e ff 90 0f 0b e8 d7 79 c7 ff 48 89 df 48 c7 c6 40 63 74 8b e8 88 df 2e ff 90 <0f> 0b e8 c0 79 c7 ff 48 89 df 48 c7 c6 20 6d 74 8b e8 71 df 2e ff
RSP: 0018:ffffc90003f8e268 EFLAGS: 00010246
RAX: c6904ff3387db700 RBX: ffffea0001b5ef00 RCX: 0000000000000000
RDX: 0000000000000007 RSI: ffffffff8d780a1b RDI: 00000000ffffffff
RBP: 0000000000000000 R08: ffffffff8f7d7477 R09: 1ffffffff1efae8e
R10: dffffc0000000000 R11: fffffbfff1efae8f R12: 1ffffd400036bde1
R13: 1ffffd400036bde0 R14: ffffea0001b5ef08 R15: 00fff20000004060
FS: 0000555572333500(0000) GS:ffff888125fe2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f57d6844000 CR3: 0000000075586000 CR4: 00000000003526f0
Call Trace:
<TASK>
iomap_readahead+0x96a/0xbc0 fs/iomap/buffered-io.c:547
iomap_bio_readahead include/linux/iomap.h:608 [inline]
erofs_readahead+0x1c3/0x3c0 fs/erofs/data.c:383
read_pages+0x17a/0x580 mm/readahead.c:163
page_cache_ra_order+0x924/0xe70 mm/readahead.c:518
filemap_readahead mm/filemap.c:2658 [inline]
filemap_get_pages+0x7ff/0x1df0 mm/filemap.c:2704
filemap_read+0x3f6/0x11a0 mm/filemap.c:2800
__kernel_read+0x4cf/0x960 fs/read_write.c:530
integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28
ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:480 [inline]
ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
ima_calc_file_hash+0x85e/0x16f0 security/integrity/ima/ima_crypto.c:568
ima_collect_measurement+0x428/0x8f0 security/integrity/ima/ima_api.c:293
process_measurement+0x1121/0x1a40 security/integrity/ima/ima_main.c:405
ima_file_check+0xd7/0x120 security/integrity/ima/ima_main.c:656
security_file_post_open+0xbb/0x290 security/security.c:2652
do_open fs/namei.c:3977 [inline]
path_openat+0x2f26/0x3830 fs/namei.c:4134
do_filp_open+0x1fa/0x410 fs/namei.c:4161
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0b08d8efc9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffec6a5d268 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f0b08fe5fa0 RCX: 00007f0b08d8efc9
RDX: 0000000000121140 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f0b08e11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000013d R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0b08fe5fa0 R14: 00007f0b08fe5fa0 R15: 0000000000000004
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:folio_end_read+0x1e9/0x230 mm/filemap.c:1530
Code: 79 c7 ff 48 89 df 48 c7 c6 20 6d 74 8b e8 9f df 2e ff 90 0f 0b e8 d7 79 c7 ff 48 89 df 48 c7 c6 40 63 74 8b e8 88 df 2e ff 90 <0f> 0b e8 c0 79 c7 ff 48 89 df 48 c7 c6 20 6d 74 8b e8 71 df 2e ff
RSP: 0018:ffffc90003f8e268 EFLAGS: 00010246
RAX: c6904ff3387db700 RBX: ffffea0001b5ef00 RCX: 0000000000000000
RDX: 0000000000000007 RSI: ffffffff8d780a1b RDI: 00000000ffffffff
RBP: 0000000000000000 R08: ffffffff8f7d7477 R09: 1ffffffff1efae8e
R10: dffffc0000000000 R11: fffffbfff1efae8f R12: 1ffffd400036bde1
R13: 1ffffd400036bde0 R14: ffffea0001b5ef08 R15: 00fff20000004060
FS: 0000555572333500(0000) GS:ffff888125ee2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30063fff CR3: 0000000075586000 CR4: 00000000003526f0

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#syz test: git://repo/address.git branch-or-commit-hash
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