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BUG: KCSAN: data-race in console_unlock / console_unlock

write to 0xffffffff84185940 of 8 bytes by task 5656 on cpu 0:
 console_unlock+0x570/0xb30 kernel/printk/printk.c:2632
 vprintk_emit+0x125/0x3d0 kernel/printk/printk.c:2174
 vprintk_default+0x22/0x30 kernel/printk/printk.c:2185
 vprintk+0x15a/0x170 kernel/printk/printk_safe.c:392
 printk+0x62/0x87 kernel/printk/printk.c:2216
 printk_stack_address arch/x86/kernel/dumpstack.c:72 [inline]
 show_trace_log_lvl+0x587/0x600 arch/x86/kernel/dumpstack.c:282
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xb7/0x103 lib/dump_stack.c:105
 dump_stack+0x11/0x1a lib/dump_stack.c:112
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail+0x23c/0x250 lib/fault-inject.c:146
 __should_failslab+0x81/0x90 mm/failslab.c:33
 should_failslab+0x5/0x20 mm/slab_common.c:1326
 slab_pre_alloc_hook mm/slab.h:494 [inline]
 slab_alloc mm/slab.c:3306 [inline]
 kmem_cache_alloc+0x46/0x2e0 mm/slab.c:3507
 mempool_alloc_slab+0x16/0x20 mm/mempool.c:513
 mempool_alloc+0x8c/0x300 mm/mempool.c:393
 bio_alloc_bioset+0xcc/0x530 block/bio.c:466
 bio_alloc include/linux/bio.h:424 [inline]
 io_submit_init_bio fs/ext4/page-io.c:401 [inline]
 io_submit_add_bh fs/ext4/page-io.c:425 [inline]
 ext4_bio_write_page+0x7c5/0xa40 fs/ext4/page-io.c:549
 mpage_submit_page fs/ext4/inode.c:2100 [inline]
 mpage_process_page_bufs+0x437/0x560 fs/ext4/inode.c:2214
 mpage_prepare_extent_to_map+0x4e6/0x640 fs/ext4/inode.c:2626
 ext4_writepages+0x6d6/0x1d30 fs/ext4/inode.c:2754
 do_writepages+0x8b/0x160 mm/page-writeback.c:2353
 filemap_fdatawrite_wbc mm/filemap.c:402 [inline]
 __filemap_fdatawrite_range mm/filemap.c:435 [inline]
 file_write_and_wait_range+0x199/0x230 mm/filemap.c:812
 ext4_sync_file+0x105/0x670 fs/ext4/fsync.c:151
 vfs_fsync_range+0x107/0x120 fs/sync.c:200
 generic_write_sync include/linux/fs.h:2950 [inline]
 ext4_buffered_write_iter+0x3af/0x400 fs/ext4/file.c:277
 ext4_file_write_iter+0x2e7/0x11a0 fs/ext4/file.c:519
 call_write_iter include/linux/fs.h:2158 [inline]
 do_iter_readv_writev+0x2cd/0x370 fs/read_write.c:729
 do_iter_write+0x192/0x5c0 fs/read_write.c:855
 vfs_iter_write+0x4c/0x70 fs/read_write.c:896
 iter_file_splice_write+0x40a/0x750 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x650 fs/splice.c:891
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x618/0xb90 fs/read_write.c:1249
 __do_sys_sendfile64 fs/read_write.c:1308 [inline]
 __se_sys_sendfile64 fs/read_write.c:1300 [inline]
 __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1300
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffffffff84185940 of 8 bytes by task 5678 on cpu 1:
 console_unlock+0x9f5/0xb30 kernel/printk/printk.c:2667
 vprintk_emit+0x125/0x3d0 kernel/printk/printk.c:2174
 vprintk_default+0x22/0x30 kernel/printk/printk.c:2185
 vprintk+0x15a/0x170 kernel/printk/printk_safe.c:392
 printk+0x62/0x87 kernel/printk/printk.c:2216
 cgroup1_root_to_use kernel/cgroup/cgroup-v1.c:1178 [inline]
 cgroup1_get_tree+0x74f/0x860 kernel/cgroup/cgroup-v1.c:1220
 vfs_get_tree+0x4a/0x1a0 fs/super.c:1498
 do_new_mount fs/namespace.c:2987 [inline]
 path_mount+0x11ca/0x1d00 fs/namespace.c:3317
 do_mount fs/namespace.c:3330 [inline]
 __do_sys_mount fs/namespace.c:3538 [inline]
 __se_sys_mount+0x23d/0x2e0 fs/namespace.c:3515
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3515
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000000084f1 -> 0x00000000000084f2

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 5678 Comm: syz-executor.5 Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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