syzbot

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BUG: KCSAN: data-race in do_mpage_readpage / set_blocksize

write to 0xffff8881004c16ee of 1 bytes by task 6106 on cpu 1:
 set_blocksize+0x215/0x270 block/bdev.c:172
 sb_set_blocksize block/bdev.c:182 [inline]
 sb_min_blocksize+0x63/0xe0 block/bdev.c:198
 ext4_load_super fs/ext4/super.c:5038 [inline]
 __ext4_fill_super fs/ext4/super.c:5259 [inline]
 ext4_fill_super+0x38b/0x3a10 fs/ext4/super.c:5733
 get_tree_bdev_flags+0x29f/0x310 fs/super.c:1636
 get_tree_bdev+0x1f/0x30 fs/super.c:1659
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5765
 vfs_get_tree+0x56/0x1e0 fs/super.c:1814
 do_new_mount+0x227/0x690 fs/namespace.c:3507
 path_mount+0x49b/0xb30 fs/namespace.c:3834
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x27c/0x2d0 fs/namespace.c:4034
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4034
 x64_sys_call+0x2c84/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881004c16ee of 1 bytes by task 4986 on cpu 0:
 do_mpage_readpage+0x55/0xcb0 fs/mpage.c:155
 mpage_readahead+0x1ad/0x2d0 fs/mpage.c:374
 blkdev_readahead+0x1c/0x30 block/fops.c:447
 read_pages+0xa0/0x540 mm/readahead.c:160
 page_cache_ra_unbounded+0x2d6/0x310 mm/readahead.c:290
 do_page_cache_ra mm/readahead.c:320 [inline]
 force_page_cache_ra mm/readahead.c:349 [inline]
 page_cache_sync_ra+0x252/0x670 mm/readahead.c:562
 page_cache_sync_readahead include/linux/pagemap.h:1394 [inline]
 filemap_get_pages+0x2c1/0x10e0 mm/filemap.c:2547
 filemap_read+0x221/0x6a0 mm/filemap.c:2647
 blkdev_read_iter+0x20e/0x2c0 block/fops.c:767
 new_sync_read fs/read_write.c:484 [inline]
 vfs_read+0x5dc/0x700 fs/read_write.c:565
 ksys_read+0xe8/0x1b0 fs/read_write.c:708
 __do_sys_read fs/read_write.c:717 [inline]
 __se_sys_read fs/read_write.c:715 [inline]
 __x64_sys_read+0x42/0x50 fs/read_write.c:715
 x64_sys_call+0x2874/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:1
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0c -> 0x0a

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 4986 Comm: udevd Not tainted 6.12.0-syzkaller-00971-g158f238aa69d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
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