==================================================================
BUG: KCSAN: data-race in read_pages / read_pages

read-write to 0xffff88812d34c380 of 4 bytes by task 23682 on cpu 0:
 read_pages+0x23c/0x530 mm/readahead.c:170
 page_cache_ra_unbounded+0x2aa/0x2e0 mm/readahead.c:269
 do_page_cache_ra mm/readahead.c:299 [inline]
 page_cache_ra_order+0xd5/0xf0 mm/readahead.c:546
 do_sync_mmap_readahead+0x410/0x450 mm/filemap.c:3141
 filemap_fault+0x426/0xc30 mm/filemap.c:3233
 __do_fault mm/memory.c:4265 [inline]
 do_read_fault mm/memory.c:4628 [inline]
 do_fault mm/memory.c:4762 [inline]
 do_pte_missing mm/memory.c:3730 [inline]
 handle_pte_fault mm/memory.c:5038 [inline]
 __handle_mm_fault mm/memory.c:5179 [inline]
 handle_mm_fault+0x13bd/0x2dd0 mm/memory.c:5344
 faultin_page mm/gup.c:956 [inline]
 __get_user_pages+0x402/0xe40 mm/gup.c:1239
 populate_vma_page_range mm/gup.c:1677 [inline]
 __mm_populate+0x216/0x330 mm/gup.c:1786
 mm_populate include/linux/mm.h:3379 [inline]
 vm_mmap_pgoff+0x1a7/0x240 mm/util.c:551
 ksys_mmap_pgoff+0x2b8/0x330 mm/mmap.c:1425
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read-write to 0xffff88812d34c380 of 4 bytes by task 23674 on cpu 1:
 read_pages+0x23c/0x530 mm/readahead.c:170
 page_cache_ra_unbounded+0x2aa/0x2e0 mm/readahead.c:269
 do_page_cache_ra mm/readahead.c:299 [inline]
 page_cache_ra_order+0xd5/0xf0 mm/readahead.c:546
 do_sync_mmap_readahead+0x410/0x450 mm/filemap.c:3141
 filemap_fault+0x426/0xc30 mm/filemap.c:3233
 __do_fault mm/memory.c:4265 [inline]
 do_shared_fault mm/memory.c:4692 [inline]
 do_fault mm/memory.c:4766 [inline]
 do_pte_missing mm/memory.c:3730 [inline]
 handle_pte_fault mm/memory.c:5038 [inline]
 __handle_mm_fault mm/memory.c:5179 [inline]
 handle_mm_fault+0x17db/0x2dd0 mm/memory.c:5344
 do_user_addr_fault arch/x86/mm/fault.c:1413 [inline]
 handle_page_fault arch/x86/mm/fault.c:1505 [inline]
 exc_page_fault+0x2f7/0x6c0 arch/x86/mm/fault.c:1561
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
 rep_movs_alternative+0x4a/0x70 arch/x86/lib/copy_user_64.S:65
 copy_user_generic arch/x86/include/asm/uaccess_64.h:112 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:133 [inline]
 copy_to_user_iter lib/iov_iter.c:25 [inline]
 iterate_ubuf include/linux/iov_iter.h:29 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:245 [inline]
 iterate_and_advance include/linux/iov_iter.h:271 [inline]
 _copy_to_iter+0x137/0xb20 lib/iov_iter.c:186
 copy_to_iter include/linux/uio.h:197 [inline]
 get_random_bytes_user+0x112/0x260 drivers/char/random.c:451
 __do_sys_getrandom drivers/char/random.c:1391 [inline]
 __se_sys_getrandom drivers/char/random.c:1364 [inline]
 __x64_sys_getrandom+0xcd/0x1a0 drivers/char/random.c:1364
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00000019 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 23674 Comm: syz-executor.0 Not tainted 6.6.0-syzkaller-16159-g3ca112b71f35 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
==================================================================
EXT4-fs error (device loop0): ext4_validate_block_bitmap:441: comm syz-executor.0: bg 0: block 234: padding at end of block bitmap is not set
EXT4-fs (loop0): Delayed block allocation failed for inode 18 at logical offset 0 with max blocks 1 with error 28
EXT4-fs (loop0): This should not happen!! Data will be lost

EXT4-fs (loop0): Total free blocks count 0
EXT4-fs (loop0): Free/Dirty block details
EXT4-fs (loop0): free_blocks=0
EXT4-fs (loop0): dirty_blocks=64
EXT4-fs (loop0): Block reservation details
EXT4-fs (loop0): i_reserved_data_blocks=4