[syzbot] [f2fs?] KMSAN: uninit-value in f2fs_sanity_check_node_footer

[syzbot <syzbot+9aac813cdc456cdd49f8@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    eb71ab2bf722 Merge tag 'bpf-fixes' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11c430ba580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=10f867da86e38691
dashboard link: https://syzkaller.appspot.com/bug?extid=9aac813cdc456cdd49f8
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/fcbe8b5437ef/disk-eb71ab2b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/245a6565a05b/vmlinux-eb71ab2b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a83b065baa80/bzImage-eb71ab2b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9aac813cdc456cdd49f8@syzkaller.appspotmail.com

syz.2.464: attempt to access beyond end of device
loop2: rw=0, sector=126984, nr_sectors = 8 limit=32735
=====================================================
BUG: KMSAN: uninit-value in f2fs_sanity_check_node_footer+0x374/0xa20 fs/f2fs/node.c:1520
 f2fs_sanity_check_node_footer+0x374/0xa20 fs/f2fs/node.c:1520
 f2fs_finish_read_bio+0xe1e/0x1d60 fs/f2fs/data.c:177
 f2fs_read_end_io+0x6ab/0x2220 fs/f2fs/data.c:-1
 bio_endio+0x1006/0x1160 block/bio.c:1792
 submit_bio_noacct+0x533/0x2960 block/blk-core.c:891
 submit_bio+0x57a/0x620 block/blk-core.c:926
 blk_crypto_submit_bio include/linux/blk-crypto.h:203 [inline]
 f2fs_submit_read_bio+0x12c/0x360 fs/f2fs/data.c:557
 f2fs_submit_page_bio+0xee2/0x1450 fs/f2fs/data.c:775
 read_node_folio+0x384/0x4b0 fs/f2fs/node.c:1481
 __get_node_folio+0x5db/0x15d0 fs/f2fs/node.c:1576
 f2fs_get_inode_folio+0x40/0x50 fs/f2fs/node.c:1623
 do_read_inode fs/f2fs/inode.c:425 [inline]
 f2fs_iget+0x1209/0x9380 fs/f2fs/inode.c:596
 f2fs_fill_super+0x8f5a/0xb2e0 fs/f2fs/super.c:5184
 get_tree_bdev_flags+0x6e6/0x920 fs/super.c:1694
 get_tree_bdev+0x38/0x50 fs/super.c:1717
 f2fs_get_tree+0x35/0x40 fs/f2fs/super.c:5436
 vfs_get_tree+0xb3/0x5d0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3763 [inline]
 do_new_mount+0x885/0x1dd0 fs/namespace.c:3839
 path_mount+0x7a2/0x20b0 fs/namespace.c:4159
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x704/0x7f0 fs/namespace.c:4338
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4338
 x64_sys_call+0x39f0/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x134/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 __alloc_frozen_pages_noprof+0x6f7/0x1020 mm/page_alloc.c:5273
 alloc_pages_mpol+0x328/0x860 mm/mempolicy.c:2484
 alloc_frozen_pages_noprof mm/mempolicy.c:2555 [inline]
 alloc_pages_noprof mm/mempolicy.c:2575 [inline]
 folio_alloc_noprof+0x108/0x360 mm/mempolicy.c:2585
 filemap_alloc_folio_noprof+0xd9/0x480 mm/filemap.c:1013
 __filemap_get_folio_mpol+0xb43/0x1960 mm/filemap.c:2006
 __filemap_get_folio include/linux/pagemap.h:774 [inline]
 filemap_grab_folio include/linux/pagemap.h:854 [inline]
 f2fs_grab_cache_folio fs/f2fs/f2fs.h:3048 [inline]
 __get_node_folio+0x56d/0x15d0 fs/f2fs/node.c:1572
 f2fs_get_inode_folio+0x40/0x50 fs/f2fs/node.c:1623
 do_read_inode fs/f2fs/inode.c:425 [inline]
 f2fs_iget+0x1209/0x9380 fs/f2fs/inode.c:596
 f2fs_fill_super+0x8f5a/0xb2e0 fs/f2fs/super.c:5184
 get_tree_bdev_flags+0x6e6/0x920 fs/super.c:1694
 get_tree_bdev+0x38/0x50 fs/super.c:1717
 f2fs_get_tree+0x35/0x40 fs/f2fs/super.c:5436
 vfs_get_tree+0xb3/0x5d0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3763 [inline]
 do_new_mount+0x885/0x1dd0 fs/namespace.c:3839
 path_mount+0x7a2/0x20b0 fs/namespace.c:4159
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x704/0x7f0 fs/namespace.c:4338
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4338
 x64_sys_call+0x39f0/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x134/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 8292 Comm: syz.2.464 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
=====================================================


---
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@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup