====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G U L ------------------------------------------------------ syz.3.2989/21588 is trying to acquire lock: ffffffff8e9b0d20 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:317 [inline] ffffffff8e9b0d20 (fs_reclaim){+.+.}-{0:0}, at: prepare_alloc_pages+0x166/0x5f0 mm/page_alloc.c:4990 but task is already holding lock: ffff888078f4ebd8 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] ffff888078f4ebd8 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_fault+0x83f/0x2e90 mm/filemap.c:3562 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #7 (mapping.invalidate_lock#2){++++}-{4:4}: down_read+0x99/0x450 kernel/locking/rwsem.c:1568 filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] do_page_cache_ra+0xfe/0x160 mm/readahead.c:333 page_cache_ra_order+0xc2f/0xf10 mm/readahead.c:538 do_sync_mmap_readahead mm/filemap.c:3406 [inline] filemap_fault+0x1900/0x2e90 mm/filemap.c:3555 __do_fault+0x10b/0x440 mm/memory.c:5474 do_read_fault mm/memory.c:5909 [inline] do_fault+0xa99/0x1750 mm/memory.c:6043 do_pte_missing mm/memory.c:4566 [inline] handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault+0x187d/0x2a00 mm/memory.c:6565 handle_mm_fault+0x37b/0xa30 mm/memory.c:6734 do_user_addr_fault+0x74c/0x12f0 arch/x86/mm/fault.c:1385 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:68 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:141 [inline] copy_from_user_iter lib/iov_iter.c:67 [inline] iterate_ubuf include/linux/iov_iter.h:30 [inline] iterate_and_advance2 include/linux/iov_iter.h:302 [inline] iterate_and_advance include/linux/iov_iter.h:330 [inline] __copy_from_iter lib/iov_iter.c:261 [inline] _copy_from_iter+0x355/0x1690 lib/iov_iter.c:272 copy_from_iter include/linux/uio.h:228 [inline] copy_from_iter_full include/linux/uio.h:245 [inline] skb_do_copy_data_nocache include/net/sock.h:2303 [inline] skb_copy_to_page_nocache include/net/sock.h:2329 [inline] tcp_sendmsg_locked+0xcab/0x4500 net/ipv4/tcp.c:1311 tcp_sendmsg+0x2e/0x50 net/ipv4/tcp.c:1452 inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:866 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] sock_write_iter+0x4ea/0x5a0 net/socket.c:1254 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1070 fs/read_write.c:688 ksys_write+0x1f8/0x250 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #6 (sk_lock-AF_INET){+.+.}-{0:0}: lock_sock_nested+0x41/0xf0 net/core/sock.c:3783 lock_sock include/net/sock.h:1713 [inline] inet_shutdown+0x67/0x410 net/ipv4/af_inet.c:915 nbd_mark_nsock_dead+0xae/0x5c0 drivers/block/nbd.c:318 recv_work+0x5fb/0x8c0 drivers/block/nbd.c:1021 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #5 (&nsock->tx_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1b10 kernel/locking/mutex.c:820 nbd_handle_cmd drivers/block/nbd.c:1143 [inline] nbd_queue_rq+0x428/0x1080 drivers/block/nbd.c:1207 blk_mq_dispatch_rq_list+0x422/0x1e70 block/blk-mq.c:2148 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xcea/0x1620 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd7/0x1c0 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x23c/0x670 block/blk-mq.c:2386 blk_mq_dispatch_list+0x51d/0x1360 block/blk-mq.c:2949 blk_mq_flush_plug_list block/blk-mq.c:2997 [inline] blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2969 __blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1230 blk_finish_plug block/blk-core.c:1257 [inline] __submit_bio+0x584/0x6c0 block/blk-core.c:649 __submit_bio_noacct_mq block/blk-core.c:722 [inline] submit_bio_noacct_nocheck+0x543/0xbf0 block/blk-core.c:753 submit_bio_noacct+0xd18/0x2000 block/blk-core.c:884 blk_crypto_submit_bio include/linux/blk-crypto.h:203 [inline] submit_bh_wbc+0x681/0x890 fs/buffer.c:2737 submit_bh fs/buffer.c:2742 [inline] block_read_full_folio+0x4c8/0x8e0 fs/buffer.c:2358 filemap_read_folio+0xfc/0x3b0 mm/filemap.c:2502 do_read_cache_folio+0x2d7/0x6b0 mm/filemap.c:4107 read_mapping_folio include/linux/pagemap.h:1017 [inline] read_part_sector+0xd1/0x370 block/partitions/core.c:724 adfspart_check_ICS+0x91/0x7d0 block/partitions/acorn.c:356 check_partition block/partitions/core.c:143 [inline] blk_add_partitions block/partitions/core.c:591 [inline] bdev_disk_changed+0x7a3/0x1250 block/partitions/core.c:695 blkdev_get_whole+0x187/0x290 block/bdev.c:756 bdev_open+0x2c7/0xe40 block/bdev.c:965 blkdev_open+0x34e/0x4f0 block/fops.c:697 do_dentry_open+0x6ab/0x14d0 fs/open.c:947 vfs_open+0x82/0x3f0 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x208c/0x31a0 fs/namei.c:4858 do_file_open+0x20e/0x430 fs/namei.c:4887 do_sys_openat2+0x10d/0x1e0 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (&cmd->lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1b10 kernel/locking/mutex.c:820 nbd_queue_rq+0xba/0x1080 drivers/block/nbd.c:1199 blk_mq_dispatch_rq_list+0x422/0x1e70 block/blk-mq.c:2148 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xcea/0x1620 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd7/0x1c0 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x23c/0x670 block/blk-mq.c:2386 blk_mq_dispatch_list+0x51d/0x1360 block/blk-mq.c:2949 blk_mq_flush_plug_list block/blk-mq.c:2997 [inline] blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2969 __blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1230 blk_finish_plug block/blk-core.c:1257 [inline] __submit_bio+0x584/0x6c0 block/blk-core.c:649 __submit_bio_noacct_mq block/blk-core.c:722 [inline] submit_bio_noacct_nocheck+0x543/0xbf0 block/blk-core.c:753 submit_bio_noacct+0xd18/0x2000 block/blk-core.c:884 blk_crypto_submit_bio include/linux/blk-crypto.h:203 [inline] submit_bh_wbc+0x681/0x890 fs/buffer.c:2737 submit_bh fs/buffer.c:2742 [inline] block_read_full_folio+0x4c8/0x8e0 fs/buffer.c:2358 filemap_read_folio+0xfc/0x3b0 mm/filemap.c:2502 do_read_cache_folio+0x2d7/0x6b0 mm/filemap.c:4107 read_mapping_folio include/linux/pagemap.h:1017 [inline] read_part_sector+0xd1/0x370 block/partitions/core.c:724 adfspart_check_ICS+0x91/0x7d0 block/partitions/acorn.c:356 check_partition block/partitions/core.c:143 [inline] blk_add_partitions block/partitions/core.c:591 [inline] bdev_disk_changed+0x7a3/0x1250 block/partitions/core.c:695 blkdev_get_whole+0x187/0x290 block/bdev.c:756 bdev_open+0x2c7/0xe40 block/bdev.c:965 blkdev_open+0x34e/0x4f0 block/fops.c:697 do_dentry_open+0x6ab/0x14d0 fs/open.c:947 vfs_open+0x82/0x3f0 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x208c/0x31a0 fs/namei.c:4858 do_file_open+0x20e/0x430 fs/namei.c:4887 do_sys_openat2+0x10d/0x1e0 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (set->srcu){.+.+}-{0:0}: srcu_lock_sync include/linux/srcu.h:199 [inline] __synchronize_srcu+0xa2/0x300 kernel/rcu/srcutree.c:1481 blk_mq_wait_quiesce_done block/blk-mq.c:284 [inline] blk_mq_wait_quiesce_done block/blk-mq.c:281 [inline] blk_mq_quiesce_queue block/blk-mq.c:304 [inline] blk_mq_quiesce_queue+0x149/0x1c0 block/blk-mq.c:299 elevator_switch+0x17b/0x7e0 block/elevator.c:576 elevator_change+0x352/0x530 block/elevator.c:681 elevator_set_default+0x29e/0x360 block/elevator.c:754 blk_register_queue+0x48e/0x630 block/blk-sysfs.c:987 __add_disk+0x73f/0xe40 block/genhd.c:528 add_disk_fwnode+0x118/0x5c0 block/genhd.c:597 add_disk include/linux/blkdev.h:794 [inline] nbd_dev_add+0x77a/0xb10 drivers/block/nbd.c:1984 nbd_init+0x291/0x2b0 drivers/block/nbd.c:2692 do_one_initcall+0x121/0x750 init/main.c:1392 do_initcall_level init/main.c:1454 [inline] do_initcalls init/main.c:1470 [inline] do_basic_setup init/main.c:1490 [inline] kernel_init_freeable+0x6ea/0x7b0 init/main.c:1703 kernel_init+0x1f/0x1e0 init/main.c:1593 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #2 (&q->elevator_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1b10 kernel/locking/mutex.c:820 queue_requests_store+0x3a7/0x690 block/blk-sysfs.c:123 queue_attr_store+0x25f/0x2f0 block/blk-sysfs.c:905 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352 iter_file_splice_write+0x830/0x10a0 fs/splice.c:736 do_splice_from fs/splice.c:936 [inline] direct_splice_actor+0x192/0x6c0 fs/splice.c:1159 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103 do_splice_direct_actor fs/splice.c:1202 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1228 do_sendfile+0xadc/0xe20 fs/read_write.c:1372 __do_sys_sendfile64 fs/read_write.c:1433 [inline] __se_sys_sendfile64 fs/read_write.c:1419 [inline] __x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1419 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&q->q_usage_counter(io)#57){++++}-{0:0}: blk_alloc_queue+0x610/0x790 block/blk-core.c:461 blk_mq_alloc_queue+0x174/0x290 block/blk-mq.c:4453 __blk_mq_alloc_disk+0x29/0x120 block/blk-mq.c:4500 nbd_dev_add+0x492/0xb10 drivers/block/nbd.c:1954 nbd_init+0x291/0x2b0 drivers/block/nbd.c:2692 do_one_initcall+0x121/0x750 init/main.c:1392 do_initcall_level init/main.c:1454 [inline] do_initcalls init/main.c:1470 [inline] do_basic_setup init/main.c:1490 [inline] kernel_init_freeable+0x6ea/0x7b0 init/main.c:1703 kernel_init+0x1f/0x1e0 init/main.c:1593 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #0 (fs_reclaim){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825 __fs_reclaim_acquire mm/page_alloc.c:4320 [inline] fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4334 might_alloc include/linux/sched/mm.h:317 [inline] prepare_alloc_pages+0x166/0x5f0 mm/page_alloc.c:4990 __alloc_frozen_pages_noprof+0x19a/0x2bc0 mm/page_alloc.c:5210 alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490 alloc_pages_noprof mm/mempolicy.c:2581 [inline] folio_alloc_noprof+0x22/0x250 mm/mempolicy.c:2591 filemap_alloc_folio_noprof.part.0+0x377/0x450 mm/filemap.c:1014 filemap_alloc_folio_noprof mm/filemap.c:2027 [inline] __filemap_get_folio_mpol+0x6a4/0xe70 mm/filemap.c:2012 __filemap_get_folio include/linux/pagemap.h:763 [inline] filemap_fault+0x888/0x2e90 mm/filemap.c:3565 __do_fault+0x10b/0x440 mm/memory.c:5474 do_read_fault mm/memory.c:5909 [inline] do_fault+0xa99/0x1750 mm/memory.c:6043 do_pte_missing mm/memory.c:4566 [inline] handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault+0x187d/0x2a00 mm/memory.c:6565 handle_mm_fault+0x37b/0xa30 mm/memory.c:6734 do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 other info that might help us debug this: Chain exists of: fs_reclaim --> sk_lock-AF_INET --> mapping.invalidate_lock#2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(mapping.invalidate_lock#2); lock(sk_lock-AF_INET); lock(mapping.invalidate_lock#2); lock(fs_reclaim); *** DEADLOCK *** 1 lock held by syz.3.2989/21588: #0: ffff888078f4ebd8 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] #0: ffff888078f4ebd8 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_fault+0x83f/0x2e90 mm/filemap.c:3562 stack backtrace: CPU: 0 UID: 0 PID: 21588 Comm: syz.3.2989 Tainted: G U L syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_circular_bug.cold+0x178/0x1c7 kernel/locking/lockdep.c:2043 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825 __fs_reclaim_acquire mm/page_alloc.c:4320 [inline] fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4334 might_alloc include/linux/sched/mm.h:317 [inline] prepare_alloc_pages+0x166/0x5f0 mm/page_alloc.c:4990 __alloc_frozen_pages_noprof+0x19a/0x2bc0 mm/page_alloc.c:5210 alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490 alloc_pages_noprof mm/mempolicy.c:2581 [inline] folio_alloc_noprof+0x22/0x250 mm/mempolicy.c:2591 filemap_alloc_folio_noprof.part.0+0x377/0x450 mm/filemap.c:1014 filemap_alloc_folio_noprof mm/filemap.c:2027 [inline] __filemap_get_folio_mpol+0x6a4/0xe70 mm/filemap.c:2012 __filemap_get_folio include/linux/pagemap.h:763 [inline] filemap_fault+0x888/0x2e90 mm/filemap.c:3565 __do_fault+0x10b/0x440 mm/memory.c:5474 do_read_fault mm/memory.c:5909 [inline] do_fault+0xa99/0x1750 mm/memory.c:6043 do_pte_missing mm/memory.c:4566 [inline] handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault+0x187d/0x2a00 mm/memory.c:6565 handle_mm_fault+0x37b/0xa30 mm/memory.c:6734 do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f4131a716f0 Code: 01 00 48 83 c0 01 48 39 f0 72 ef e9 89 fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 48 8b 0d 91 09 3a 00 31 c0 48 81 ce ff ff ff 3f <48> 3b 34 c1 74 14 48 83 c0 01 48 83 f8 04 0f 84 39 fe ff ff 48 3b RSP: 002b:00007fffce1698b0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffffffff828d8e3c RCX: 000000110c230000 RDX: 0000000000000e3c RSI: ffffffffbfffffff RDI: 000000000000001d RBP: 0000000000000000 R08: 00007f4131e00000 R09: 00007f4131e02000 R10: 00000000828d8e40 R11: 000000000000001d R12: 00007f4131e16308 R13: 0000000000000000 R14: ffffffff828d8756 R15: 00007f4132945720