======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.1.2210/14833 is trying to acquire lock:
ffffffff8e5643a0 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:318 [inline]
ffffffff8e5643a0 (fs_reclaim){+.+.}-{0:0}, at: prepare_alloc_pages+0x162/0x610 mm/page_alloc.c:4951
but task is already holding lock:
ffff88813ff1ace0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:387 [inline]
ffff88813ff1ace0 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:368 [inline]
ffff88813ff1ace0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x35/0x6e0 mm/mmap_lock.c:428
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #7 (&mm->mmap_lock){++++}-{4:4}:
__might_fault mm/memory.c:7081 [inline]
__might_fault+0x113/0x190 mm/memory.c:7075
_copy_from_iter+0x1c2/0x1720 lib/iov_iter.c:259
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:2269 [inline]
skb_copy_to_page_nocache include/net/sock.h:2295 [inline]
tcp_sendmsg_locked+0x2900/0x42e0 net/ipv4/tcp.c:1272
tcp_sendmsg+0x2e/0x50 net/ipv4/tcp.c:1413
inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:853
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
sock_write_iter+0x509/0x610 net/socket.c:1195
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x7d3/0x11d0 fs/read_write.c:686
ksys_write+0x1f8/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 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:3720
lock_sock include/net/sock.h:1679 [inline]
inet_shutdown+0x67/0x440 net/ipv4/af_inet.c:907
nbd_mark_nsock_dead+0xae/0x5d0 drivers/block/nbd.c:318
recv_work+0x671/0xa80 drivers/block/nbd.c:1018
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
process_scheduled_works kernel/workqueue.c:3346 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 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:598 [inline]
__mutex_lock+0x193/0x1060 kernel/locking/mutex.c:760
nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
nbd_queue_rq+0x423/0x12d0 drivers/block/nbd.c:1204
blk_mq_dispatch_rq_list+0x416/0x1e20 block/blk-mq.c:2129
__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+0xcb7/0x15f0 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd8/0x1b0 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x239/0x670 block/blk-mq.c:2367
blk_mq_dispatch_list+0x514/0x1310 block/blk-mq.c:2928
blk_mq_flush_plug_list block/blk-mq.c:2976 [inline]
blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2948
__blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1225
blk_finish_plug block/blk-core.c:1252 [inline]
blk_finish_plug block/blk-core.c:1249 [inline]
__submit_bio+0x545/0x690 block/blk-core.c:651
__submit_bio_noacct_mq block/blk-core.c:724 [inline]
submit_bio_noacct_nocheck+0x53d/0xc10 block/blk-core.c:755
submit_bio_noacct+0xbbb/0x1f60 block/blk-core.c:879
submit_bh fs/buffer.c:2829 [inline]
block_read_full_folio+0x34e/0x850 fs/buffer.c:2447
filemap_read_folio+0xc8/0x2a0 mm/filemap.c:2444
do_read_cache_folio+0x263/0x5c0 mm/filemap.c:4024
read_mapping_folio include/linux/pagemap.h:999 [inline]
read_part_sector+0xd4/0x370 block/partitions/core.c:722
adfspart_check_ICS+0x93/0x940 block/partitions/acorn.c:360
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x723/0x1520 block/partitions/core.c:693
blkdev_get_whole+0x187/0x290 block/bdev.c:748
bdev_open+0x2c7/0xe40 block/bdev.c:957
blkdev_open+0x34e/0x4f0 block/fops.c:701
do_dentry_open+0x982/0x1530 fs/open.c:965
vfs_open+0x82/0x3f0 fs/open.c:1097
do_open fs/namei.c:3975 [inline]
path_openat+0x1de4/0x2cb0 fs/namei.c:4134
do_filp_open+0x20b/0x470 fs/namei.c:4161
do_sys_openat2+0x11b/0x1d0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 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:598 [inline]
__mutex_lock+0x193/0x1060 kernel/locking/mutex.c:760
nbd_queue_rq+0xbd/0x12d0 drivers/block/nbd.c:1196
blk_mq_dispatch_rq_list+0x416/0x1e20 block/blk-mq.c:2129
__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+0xcb7/0x15f0 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd8/0x1b0 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x239/0x670 block/blk-mq.c:2367
blk_mq_dispatch_list+0x514/0x1310 block/blk-mq.c:2928
blk_mq_flush_plug_list block/blk-mq.c:2976 [inline]
blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2948
__blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1225
blk_finish_plug block/blk-core.c:1252 [inline]
blk_finish_plug block/blk-core.c:1249 [inline]
__submit_bio+0x545/0x690 block/blk-core.c:651
__submit_bio_noacct_mq block/blk-core.c:724 [inline]
submit_bio_noacct_nocheck+0x53d/0xc10 block/blk-core.c:755
submit_bio_noacct+0xbbb/0x1f60 block/blk-core.c:879
submit_bh fs/buffer.c:2829 [inline]
block_read_full_folio+0x34e/0x850 fs/buffer.c:2447
filemap_read_folio+0xc8/0x2a0 mm/filemap.c:2444
do_read_cache_folio+0x263/0x5c0 mm/filemap.c:4024
read_mapping_folio include/linux/pagemap.h:999 [inline]
read_part_sector+0xd4/0x370 block/partitions/core.c:722
adfspart_check_ICS+0x93/0x940 block/partitions/acorn.c:360
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x723/0x1520 block/partitions/core.c:693
blkdev_get_whole+0x187/0x290 block/bdev.c:748
bdev_open+0x2c7/0xe40 block/bdev.c:957
blkdev_open+0x34e/0x4f0 block/fops.c:701
do_dentry_open+0x982/0x1530 fs/open.c:965
vfs_open+0x82/0x3f0 fs/open.c:1097
do_open fs/namei.c:3975 [inline]
path_openat+0x1de4/0x2cb0 fs/namei.c:4134
do_filp_open+0x20b/0x470 fs/namei.c:4161
do_sys_openat2+0x11b/0x1d0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 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:173 [inline]
__synchronize_srcu+0xa1/0x290 kernel/rcu/srcutree.c:1439
blk_mq_wait_quiesce_done block/blk-mq.c:283 [inline]
blk_mq_wait_quiesce_done block/blk-mq.c:280 [inline]
blk_mq_quiesce_queue block/blk-mq.c:303 [inline]
blk_mq_quiesce_queue+0x149/0x1b0 block/blk-mq.c:298
elevator_switch+0x17d/0x810 block/elevator.c:588
elevator_change+0x391/0x5d0 block/elevator.c:691
elevator_set_default+0x2e9/0x380 block/elevator.c:767
blk_register_queue+0x384/0x4e0 block/blk-sysfs.c:942
__add_disk+0x74a/0xf00 block/genhd.c:528
add_disk_fwnode+0x13f/0x5d0 block/genhd.c:597
add_disk include/linux/blkdev.h:775 [inline]
nbd_dev_add+0x783/0xbb0 drivers/block/nbd.c:1981
nbd_init+0x181/0x320 drivers/block/nbd.c:2688
do_one_initcall+0x123/0x6e0 init/main.c:1283
do_initcall_level init/main.c:1345 [inline]
do_initcalls init/main.c:1361 [inline]
do_basic_setup init/main.c:1380 [inline]
kernel_init_freeable+0x5c8/0x920 init/main.c:1593
kernel_init+0x1c/0x2b0 init/main.c:1483
ret_from_fork+0x675/0x7d0 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:598 [inline]
__mutex_lock+0x193/0x1060 kernel/locking/mutex.c:760
elevator_change+0x17d/0x5d0 block/elevator.c:689
elv_iosched_store+0x315/0x3c0 block/elevator.c:824
queue_attr_store+0x26b/0x310 block/blk-sysfs.c:869
sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142
kernfs_fop_write_iter+0x3af/0x570 fs/kernfs/file.c:352
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x7d3/0x11d0 fs/read_write.c:686
ksys_write+0x12a/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (&q->q_usage_counter(io)#62){++++}-{0:0}:
blk_alloc_queue+0x619/0x760 block/blk-core.c:461
blk_mq_alloc_queue+0x172/0x280 block/blk-mq.c:4399
__blk_mq_alloc_disk+0x29/0x120 block/blk-mq.c:4446
nbd_dev_add+0x492/0xbb0 drivers/block/nbd.c:1951
nbd_init+0x181/0x320 drivers/block/nbd.c:2688
do_one_initcall+0x123/0x6e0 init/main.c:1283
do_initcall_level init/main.c:1345 [inline]
do_initcalls init/main.c:1361 [inline]
do_basic_setup init/main.c:1380 [inline]
kernel_init_freeable+0x5c8/0x920 init/main.c:1593
kernel_init+0x1c/0x2b0 init/main.c:1483
ret_from_fork+0x675/0x7d0 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+0x126f/0x1c90 kernel/locking/lockdep.c:5237
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825
__fs_reclaim_acquire mm/page_alloc.c:4269 [inline]
fs_reclaim_acquire+0x102/0x150 mm/page_alloc.c:4283
might_alloc include/linux/sched/mm.h:318 [inline]
prepare_alloc_pages+0x162/0x610 mm/page_alloc.c:4951
__alloc_frozen_pages_noprof+0x18b/0x2470 mm/page_alloc.c:5172
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline]
alloc_pages_noprof+0x131/0x390 mm/mempolicy.c:2507
pagetable_alloc_noprof include/linux/mm.h:2980 [inline]
pmd_alloc_one_noprof include/asm-generic/pgalloc.h:142 [inline]
__pmd_alloc+0x3b/0x8b0 mm/memory.c:6573
pmd_alloc include/linux/mm.h:2937 [inline]
__handle_mm_fault+0xada/0x2aa0 mm/memory.c:6279
handle_mm_fault+0x589/0xd10 mm/memory.c:6487
do_user_addr_fault+0x7a6/0x1370 arch/x86/mm/fault.c:1387
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x64/0xc0 arch/x86/mm/fault.c:1532
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]
_inline_copy_from_user include/linux/uaccess.h:178 [inline]
_copy_from_user+0x98/0xd0 lib/usercopy.c:18
copy_from_user include/linux/uaccess.h:212 [inline]
uhid_event_from_user drivers/hid/uhid.c:473 [inline]
uhid_char_write+0x160/0x1060 drivers/hid/uhid.c:738
vfs_write+0x2a0/0x11d0 fs/read_write.c:684
ksys_write+0x1f8/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
fs_reclaim --> sk_lock-AF_INET --> &mm->mmap_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
rlock(&mm->mmap_lock);
lock(sk_lock-AF_INET);
lock(&mm->mmap_lock);
lock(fs_reclaim);
*** DEADLOCK ***
2 locks held by syz.1.2210/14833:
#0: ffff88805d2b8068 (&uhid->devlock){+.+.}-{4:4}, at: uhid_char_write+0x6b/0x1060 drivers/hid/uhid.c:731
#1: ffff88813ff1ace0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:387 [inline]
#1: ffff88813ff1ace0 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:368 [inline]
#1: ffff88813ff1ace0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x35/0x6e0 mm/mmap_lock.c:428
stack backtrace:
CPU: 0 UID: 0 PID: 14833 Comm: syz.1.2210 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2043
check_noncircular+0x14c/0x170 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+0x126f/0x1c90 kernel/locking/lockdep.c:5237
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825
__fs_reclaim_acquire mm/page_alloc.c:4269 [inline]
fs_reclaim_acquire+0x102/0x150 mm/page_alloc.c:4283
might_alloc include/linux/sched/mm.h:318 [inline]
prepare_alloc_pages+0x162/0x610 mm/page_alloc.c:4951
__alloc_frozen_pages_noprof+0x18b/0x2470 mm/page_alloc.c:5172
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline]
alloc_pages_noprof+0x131/0x390 mm/mempolicy.c:2507
pagetable_alloc_noprof include/linux/mm.h:2980 [inline]
pmd_alloc_one_noprof include/asm-generic/pgalloc.h:142 [inline]
__pmd_alloc+0x3b/0x8b0 mm/memory.c:6573
pmd_alloc include/linux/mm.h:2937 [inline]
__handle_mm_fault+0xada/0x2aa0 mm/memory.c:6279
handle_mm_fault+0x589/0xd10 mm/memory.c:6487
do_user_addr_fault+0x7a6/0x1370 arch/x86/mm/fault.c:1387
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x64/0xc0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:74
Code: 3c 04 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 73 e8 eb c5 <f3> a4 c3 cc cc cc cc 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48
RSP: 0018:ffffc900044efca0 EFLAGS: 00050202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 000000000000111c
RDX: ffffed100ba5723a RSI: 0000000000000000 RDI: ffff88805d2b80b0
RBP: 000000000000111c R08: 0000000000000001 R09: ffffed100ba57239
R10: ffff88805d2b91cb R11: 0000000000000000 R12: 0000000000000000
R13: ffff88805d2b80b0 R14: 000000000000111c R15: ffff88805d2b80b0
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]
_inline_copy_from_user include/linux/uaccess.h:178 [inline]
_copy_from_user+0x98/0xd0 lib/usercopy.c:18
copy_from_user include/linux/uaccess.h:212 [inline]
uhid_event_from_user drivers/hid/uhid.c:473 [inline]
uhid_char_write+0x160/0x1060 drivers/hid/uhid.c:738
vfs_write+0x2a0/0x11d0 fs/read_write.c:684
ksys_write+0x1f8/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f20be38efc9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f20bf2ea038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f20be5e6090 RCX: 00007f20be38efc9
RDX: 000000000000fccd RSI: 0000000000000000 RDI: 0000000000000002
RBP: 00007f20be411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f20be5e6128 R14: 00007f20be5e6090 R15: 00007fffa2d490b8
</TASK>
----------------
Code disassembly (best guess):
0: 3c 04 cmp $0x4,%al
2: 00 66 66 add %ah,0x66(%rsi)
5: 2e 0f 1f 84 00 00 00 cs nopl 0x0(%rax,%rax,1)
c: 00 00
e: 66 90 xchg %ax,%ax
10: 48 8b 06 mov (%rsi),%rax
13: 48 89 07 mov %rax,(%rdi)
16: 48 83 c6 08 add $0x8,%rsi
1a: 48 83 c7 08 add $0x8,%rdi
1e: 83 e9 08 sub $0x8,%ecx
21: 74 db je 0xfffffffe
23: 83 f9 08 cmp $0x8,%ecx
26: 73 e8 jae 0x10
28: eb c5 jmp 0xffffffef
* 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction
2c: c3 ret
2d: cc int3
2e: cc int3
2f: cc int3
30: cc int3
31: 48 8b 06 mov (%rsi),%rax
34: 48 89 07 mov %rax,(%rdi)
37: 48 8d 47 08 lea 0x8(%rdi),%rax
3b: 48 83 e0 f8 and $0xfffffffffffffff8,%rax
3f: 48 rex.W