================================================================== BUG: KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init write to 0xffff888101c3bd50 of 8 bytes by task 5562 on cpu 1: blk_mq_rq_ctx_init+0x3dc/0x4e0 block/blk-mq.c:351 __blk_mq_alloc_request+0x270/0x290 block/blk-mq.c:406 blk_mq_submit_bio+0x27f/0xec0 block/blk-mq.c:2211 __submit_bio+0x41a/0x480 block/blk-core.c:929 __submit_bio_noacct_mq block/blk-core.c:1009 [inline] submit_bio_noacct+0x46d/0x530 block/blk-core.c:1039 submit_bio+0x10c/0x190 submit_bh_wbc+0x2f3/0x330 fs/buffer.c:3054 submit_bh fs/buffer.c:3060 [inline] write_dirty_buffer+0xde/0xf0 fs/buffer.c:3128 fat_sync_bhs+0x52/0x160 fs/fat/misc.c:361 fat_alloc_clusters+0x95a/0xab0 fs/fat/fatent.c:540 fat_add_cluster fs/fat/inode.c:108 [inline] __fat_get_block fs/fat/inode.c:155 [inline] fat_get_block+0x267/0x610 fs/fat/inode.c:190 __block_write_begin_int+0x4c5/0x1080 fs/buffer.c:2010 __block_write_begin fs/buffer.c:2060 [inline] block_write_begin fs/buffer.c:2120 [inline] cont_write_begin+0x542/0x870 fs/buffer.c:2469 fat_write_begin+0x61/0xf0 fs/fat/inode.c:235 generic_perform_write+0x1b8/0x3e0 mm/filemap.c:3770 __generic_file_write_iter+0x174/0x310 mm/filemap.c:3897 generic_file_write_iter+0x75/0x130 mm/filemap.c:3929 call_write_iter include/linux/fs.h:2163 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x7bc/0x900 fs/read_write.c:594 ksys_write+0xd9/0x190 fs/read_write.c:647 __do_sys_write fs/read_write.c:659 [inline] __se_sys_write fs/read_write.c:656 [inline] __x64_sys_write+0x3e/0x50 fs/read_write.c:656 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff888101c3bd50 of 8 bytes by task 5567 on cpu 0: blk_mq_rq_ctx_init+0x3ca/0x4e0 block/blk-mq.c:351 __blk_mq_alloc_request+0x270/0x290 block/blk-mq.c:406 blk_mq_submit_bio+0x27f/0xec0 block/blk-mq.c:2211 __submit_bio+0x41a/0x480 block/blk-core.c:929 __submit_bio_noacct_mq block/blk-core.c:1009 [inline] submit_bio_noacct+0x46d/0x530 block/blk-core.c:1039 submit_bio+0x10c/0x190 submit_bh_wbc+0x2f3/0x330 fs/buffer.c:3054 submit_bh fs/buffer.c:3060 [inline] __sync_dirty_buffer+0x136/0x1e0 fs/buffer.c:3155 sync_dirty_buffer+0x16/0x20 fs/buffer.c:3168 fat_mirror_bhs+0x24b/0x330 fs/fat/fatent.c:399 fat_ent_write+0xc2/0xd0 fs/fat/fatent.c:422 fat_chain_add+0x15b/0x410 fs/fat/misc.c:130 fat_add_cluster fs/fat/inode.c:113 [inline] __fat_get_block fs/fat/inode.c:155 [inline] fat_get_block+0x48d/0x610 fs/fat/inode.c:190 __block_write_begin_int+0x4c5/0x1080 fs/buffer.c:2010 __block_write_begin fs/buffer.c:2060 [inline] block_write_begin fs/buffer.c:2120 [inline] cont_write_begin+0x542/0x870 fs/buffer.c:2469 fat_write_begin+0x61/0xf0 fs/fat/inode.c:235 generic_perform_write+0x1b8/0x3e0 mm/filemap.c:3770 __generic_file_write_iter+0x215/0x310 mm/filemap.c:3865 generic_file_write_iter+0x75/0x130 mm/filemap.c:3929 call_write_iter include/linux/fs.h:2163 [inline] do_iter_readv_writev+0x2de/0x380 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+0x43a/0x790 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+0x106/0x190 fs/splice.c:979 do_sendfile+0x63e/0xbb0 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1314 [inline] __se_sys_sendfile64 fs/read_write.c:1300 [inline] __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1300 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000000000001141 -> 0x0000000000001142 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 5567 Comm: syz-executor.5 Not tainted 5.15.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== syz-executor.5 (5567) used greatest stack depth: 9680 bytes left