syzbot

netlink: 56 bytes leftover after parsing attributes in process `syz.2.1168'.
loop2: detected capacity change from 0 to 1024
EXT4-fs: Ignoring removed orlov option
EXT4-fs: Ignoring removed nomblk_io_submit option
==================================================================
BUG: KCSAN: data-race in __filemap_add_folio / filemap_write_and_wait_range

read-write to 0xffff8881006343f0 of 8 bytes by task 3306 on cpu 0:
 __filemap_add_folio+0x430/0x6f0 mm/filemap.c:920
 filemap_add_folio+0x9c/0x1b0 mm/filemap.c:972
 page_cache_ra_unbounded+0x175/0x310 mm/readahead.c:268
 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

read to 0xffff8881006343f0 of 8 bytes by task 8835 on cpu 1:
 mapping_needs_writeback mm/filemap.c:635 [inline]
 filemap_write_and_wait_range+0x59/0x360 mm/filemap.c:684
 filemap_write_and_wait include/linux/pagemap.h:68 [inline]
 sync_blockdev block/bdev.c:219 [inline]
 set_blocksize+0x1d0/0x270 block/bdev.c:171
 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

value changed: 0x0000000000000005 -> 0x0000000000000006

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 8835 Comm: syz.2.1168 Not tainted 6.12.0-syzkaller-01892-g8f7c8b88bda4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
==================================================================
EXT4-fs (loop2): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.