==================================================================
BUG: KCSAN: data-race in __mod_timer / blk_add_timer

write to 0xffff888101dd03c8 of 8 bytes by task 1903 on cpu 1:
 __mod_timer+0x720/0xc30 kernel/time/timer.c:1052
 mod_timer+0x1b/0x20 kernel/time/timer.c:1108
 blk_add_timer+0x18b/0x1a0 block/blk-timeout.c:164
 blk_mq_start_request+0xfe/0x290 block/blk-mq.c:1048
 loop_queue_rq+0x42/0x5b0 drivers/block/loop.c:1804
 __blk_mq_issue_directly+0x6f/0x420 block/blk-mq.c:2330
 __blk_mq_try_issue_directly+0x25d/0x2c0 block/blk-mq.c:2383
 blk_mq_request_issue_directly+0x83/0x100 block/blk-mq.c:2429
 blk_mq_plug_issue_direct+0x166/0x5e0 block/blk-mq.c:2221
 blk_mq_flush_plug_list+0xbc/0x460 block/blk-mq.c:2258
 blk_flush_plug+0x25a/0x2b0 block/blk-core.c:1593
 blk_finish_plug+0x44/0x60 block/blk-core.c:1617
 read_pages+0x34b/0x5f0 mm/readahead.c:149
 page_cache_ra_unbounded+0x3d2/0x430 mm/readahead.c:238
 do_page_cache_ra mm/readahead.c:268 [inline]
 force_page_cache_ra+0x1e6/0x220 mm/readahead.c:300
 page_cache_sync_ra+0xcc/0xe0 mm/readahead.c:574
 page_cache_sync_readahead include/linux/pagemap.h:1029 [inline]
 filemap_get_pages mm/filemap.c:2556 [inline]
 filemap_read+0x3eb/0x16d0 mm/filemap.c:2642
 generic_file_read_iter+0x72/0x2a0 mm/filemap.c:2792
 blkdev_read_iter+0x96/0x140 block/fops.c:583
 call_read_iter include/linux/fs.h:2156 [inline]
 new_sync_read fs/read_write.c:400 [inline]
 vfs_read+0x66c/0x750 fs/read_write.c:481
 ksys_read+0xd9/0x190 fs/read_write.c:619
 __do_sys_read fs/read_write.c:629 [inline]
 __se_sys_read fs/read_write.c:627 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:627
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888101dd03c8 of 8 bytes by task 25329 on cpu 0:
 blk_add_timer+0x11f/0x1a0
 blk_mq_start_request+0xfe/0x290 block/blk-mq.c:1048
 loop_queue_rq+0x42/0x5b0 drivers/block/loop.c:1804
 __blk_mq_issue_directly+0x6f/0x420 block/blk-mq.c:2330
 __blk_mq_try_issue_directly+0x25d/0x2c0 block/blk-mq.c:2383
 blk_mq_try_issue_directly+0xab/0x240 block/blk-mq.c:2413
 blk_mq_submit_bio+0xdeb/0x1470
 __submit_bio+0x131/0x340 block/blk-core.c:851
 __submit_bio_noacct_mq block/blk-core.c:926 [inline]
 submit_bio_noacct+0x418/0x4e0 block/blk-core.c:952
 submit_bio+0x10c/0x180
 submit_bh_wbc+0x2db/0x320 fs/buffer.c:3054
 submit_bh+0x21/0x30 fs/buffer.c:3060
 __ext4_read_bh fs/ext4/super.c:156 [inline]
 ext4_read_bh+0xf1/0x170 fs/ext4/super.c:180
 ext4_read_bh_lock fs/ext4/super.c:192 [inline]
 __ext4_sb_bread_gfp fs/ext4/super.c:224 [inline]
 ext4_sb_bread_unmovable+0xf7/0x1a0 fs/ext4/super.c:241
 ext4_fill_super+0x427/0x78f0 fs/ext4/super.c:3947
 mount_bdev+0x1e8/0x290 fs/super.c:1370
 ext4_mount+0x2d/0x40 fs/ext4/super.c:6523
 legacy_get_tree+0x70/0xc0 fs/fs_context.c:610
 vfs_get_tree+0x4a/0x1a0 fs/super.c:1500
 do_new_mount fs/namespace.c:2988 [inline]
 path_mount+0x11cf/0x1c40 fs/namespace.c:3318
 do_mount fs/namespace.c:3331 [inline]
 __do_sys_mount fs/namespace.c:3539 [inline]
 __se_sys_mount+0x24b/0x2f0 fs/namespace.c:3516
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3516
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x000000010000357b -> 0x000000010000405f

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 25329 Comm: syz-executor.1 Not tainted 5.16.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
[EXT4 FS bs=1024, gc=1, bpg=8192, ipg=32, mo=e000c018, mo2=0002]
System zones: 1-2, 19-19, 35-38, 46-46
EXT4-fs error (device loop1): ext4_orphan_get:1419: comm syz-executor.1: bad orphan inode 1306548338
EXT4-fs (loop1): mounted filesystem without journal. Opts: ,errors=continue. Quota mode: none.