syzbot

EXT4-fs error (device loop0): ext4_quota_enable:7232: inode #3: comm syz.0.11898: iget: special inode unallocated
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
==================================================================
BUG: KCSAN: data-race in _copy_to_iter / memcpy_and_pad

read to 0xffff88812ede4400 of 512 bytes by task 15400 on cpu 1:
 instrument_copy_to_user include/linux/instrumented.h:130 [inline]
 copy_to_user_iter lib/iov_iter.c:24 [inline]
 iterate_ubuf include/linux/iov_iter.h:30 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:302 [inline]
 iterate_and_advance include/linux/iov_iter.h:330 [inline]
 _copy_to_iter+0x130/0xea0 lib/iov_iter.c:197
 copy_page_to_iter+0x174/0x210 lib/iov_iter.c:374
 copy_folio_to_iter include/linux/uio.h:204 [inline]
 filemap_read+0x3ed/0xa20 mm/filemap.c:2865
 blkdev_read_iter+0x21e/0x2d0 block/fops.c:830
 new_sync_read fs/read_write.c:493 [inline]
 vfs_read+0x699/0x7c0 fs/read_write.c:574
 ksys_read+0xdc/0x1a0 fs/read_write.c:716
 __do_sys_read fs/read_write.c:725 [inline]
 __se_sys_read fs/read_write.c:723 [inline]
 __x64_sys_read+0x40/0x50 fs/read_write.c:723
 x64_sys_call+0x2886/0x3020 arch/x86/include/generated/asm/syscalls_64.h:1
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff88812ede45b9 of 15 bytes by task 16906 on cpu 0:
 memcpy_and_pad+0x5a/0x80 lib/string_helpers.c:1009
 ext4_update_super+0x451/0xba0 fs/ext4/super.c:6262
 ext4_commit_super+0x40/0x260 fs/ext4/super.c:6305
 ext4_handle_error+0x46f/0x570 fs/ext4/super.c:725
 __ext4_error_inode+0x1af/0x3a0 fs/ext4/super.c:871
 __ext4_iget+0x1634/0x2400 fs/ext4/inode.c:-1
 ext4_quota_enable fs/ext4/super.c:7232 [inline]
 ext4_enable_quotas+0x260/0x400 fs/ext4/super.c:7268
 __ext4_fill_super fs/ext4/super.c:5692 [inline]
 ext4_fill_super+0x3309/0x3760 fs/ext4/super.c:5828
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1634
 get_tree_bdev+0x1f/0x30 fs/super.c:1657
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5860
 vfs_get_tree+0x57/0x1d0 fs/super.c:1694
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3765 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3841
 path_mount+0x4ad/0xb90 fs/namespace.c:4161
 do_mount fs/namespace.c:4174 [inline]
 __do_sys_mount fs/namespace.c:4390 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4367
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4367
 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 16906 Comm: syz.0.11898 Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
==================================================================
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs warning (device loop0): ext4_enable_quotas:7276: Failed to enable quota tracking (type=0, err=-117, ino=3). Please run e2fsck to fix.
EXT4-fs (loop0): mount failed