syzbot

 sign-in | mailing list | source | docs | 🏰
🐞 Open [1349]
≡ Subsystems
🐞 Fixed [7125]
🐞 Invalid [18851]
⬇ Missing Backports [220]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
✨ AI
💬 Send us feedback

possible deadlock in lock_mm_and_find_vma (4)

Status: upstream: reported on 2026/02/26 14:54
Subsystems: mm
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+709f5ab0e03871dec50a@syzkaller.appspotmail.com
First crash: 98d, last: 18m
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
6c634c14-a623-4778-ac1d-8c0ad2ba4bfd assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ possible deadlock in lock_mm_and_find_vma (4) 2026/05/24 20:41 2026/05/24 20:41 2026/05/24 21:35 c69befb30ac10e158cc9d1557b508ee3f0eca1de
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly mm report (Apr 2026) 0 (1) 2026/04/22 09:08
[syzbot] [mm?] possible deadlock in lock_mm_and_find_vma (4) 2 (3) 2026/02/26 18:04
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in lock_mm_and_find_vma (2) mm 4 C 6626 566d 638d 28/29 fixed on 2024/11/14 10:09
upstream possible deadlock in lock_mm_and_find_vma (3) mm ntfs3 4 11 220d 543d 0/29 auto-obsoleted due to no activity on 2026/01/31 12:47
upstream possible deadlock in lock_mm_and_find_vma exfat 4 C error 2 1033d 1053d 23/29 fixed on 2023/10/12 12:48

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L     
------------------------------------------------------
dhcpcd/5271 is trying to acquire lock:
ffffffff8e9b1840 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:317 [inline]
ffffffff8e9b1840 (fs_reclaim){+.+.}-{0:0}, at: prepare_alloc_pages+0x166/0x5f0 mm/page_alloc.c:4995

but task is already holding lock:
ffff888039499bb8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:611 [inline]
ffff888039499bb8 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:441 [inline]
ffff888039499bb8 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x35/0x6f0 mm/mmap_lock.c:501

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #7 (&mm->mmap_lock){++++}-{4:4}:
       __might_fault+0xde/0x140 mm/memory.c:7324
       _inline_copy_from_user include/linux/uaccess.h:169 [inline]
       _copy_from_user+0x29/0xd0 lib/usercopy.c:18
       copy_from_user include/linux/uaccess.h:223 [inline]
       csum_and_copy_from_user include/net/checksum.h:31 [inline]
       copy_from_user_iter_csum net/core/skbuff.c:7402 [inline]
       iterate_ubuf include/linux/iov_iter.h:30 [inline]
       iterate_and_advance2 include/linux/iov_iter.h:302 [inline]
       csum_and_copy_from_iter_full+0x21a/0x1fd0 net/core/skbuff.c:7414
       ip_generic_getfrag+0x172/0x270 net/ipv4/ip_output.c:942
       raw6_getfrag+0x235/0x2a0 net/ipv6/raw.c:739
       __ip6_append_data+0x3fc8/0x4b40 net/ipv6/ip6_output.c:1733
       ip6_append_data net/ipv6/ip6_output.c:1886 [inline]
       ip6_append_data+0x10b/0x410 net/ipv6/ip6_output.c:1855
       rawv6_sendmsg+0x169c/0x4420 net/ipv6/raw.c:913
       inet_sendmsg+0x11c/0x140 net/ipv4/af_inet.c:866
       sock_sendmsg_nosec net/socket.c:787 [inline]
       __sock_sendmsg net/socket.c:802 [inline]
       ____sys_sendmsg+0x98d/0xb70 net/socket.c:2698
       ___sys_sendmsg+0x190/0x1e0 net/socket.c:2752
       __sys_sendmsg+0x170/0x220 net/socket.c:2784
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #6 (sk_lock-AF_INET6){+.+.}-{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
       sock_shutdown+0x16b/0x200 drivers/block/nbd.c:411
       nbd_clear_sock drivers/block/nbd.c:1427 [inline]
       nbd_config_put+0x1eb/0x750 drivers/block/nbd.c:1451
       nbd_genl_connect+0xaf8/0x1a40 drivers/block/nbd.c:2248
       genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
       genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
       genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
       netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
       netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
       netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344
       netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
       sock_sendmsg_nosec net/socket.c:787 [inline]
       __sock_sendmsg net/socket.c:802 [inline]
       ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698
       ___sys_sendmsg+0x190/0x1e0 net/socket.c:2752
       __sys_sendmsg+0x170/0x220 net/socket.c:2784
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #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+0x6d8/0x1660 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+0x10b/0xf80 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+0x6d8/0x1660 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+0x10b/0xf80 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
       elevator_change+0x1bc/0x530 block/elevator.c:679
       elevator_set_none+0x92/0xf0 block/elevator.c:769
       blk_mq_elv_switch_none block/blk-mq.c:5131 [inline]
       __blk_mq_update_nr_hw_queues block/blk-mq.c:5176 [inline]
       blk_mq_update_nr_hw_queues+0x4c1/0x15f0 block/blk-mq.c:5241
       nbd_start_device+0x1a6/0xbd0 drivers/block/nbd.c:1489
       nbd_genl_connect+0xff2/0x1a40 drivers/block/nbd.c:2239
       genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
       genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
       genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
       netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
       netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
       netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344
       netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
       sock_sendmsg_nosec net/socket.c:787 [inline]
       __sock_sendmsg net/socket.c:802 [inline]
       ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698
       ___sys_sendmsg+0x190/0x1e0 net/socket.c:2752
       __sys_sendmsg+0x170/0x220 net/socket.c:2784
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&q->q_usage_counter(io)#49){++++}-{0:0}:
       blk_alloc_queue+0x610/0x790 block/blk-core.c:461
       blk_mq_alloc_queue+0x174/0x290 block/blk-mq.c:4450
       __blk_mq_alloc_disk+0x29/0x120 block/blk-mq.c:4497
       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:4325 [inline]
       fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4339
       might_alloc include/linux/sched/mm.h:317 [inline]
       prepare_alloc_pages+0x166/0x5f0 mm/page_alloc.c:4995
       __alloc_frozen_pages_noprof+0x19a/0x2bc0 mm/page_alloc.c:5215
       alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490
       folio_alloc_mpol_noprof+0x36/0x260 mm/mempolicy.c:2509
       vma_alloc_folio_noprof+0xed/0x1d0 mm/mempolicy.c:2544
       folio_prealloc mm/memory.c:1193 [inline]
       wp_page_copy mm/memory.c:3859 [inline]
       do_wp_page+0x1ee1/0x4350 mm/memory.c:4320
       handle_pte_fault mm/memory.c:6427 [inline]
       __handle_mm_fault+0x1ab6/0x2a00 mm/memory.c:6549
       handle_mm_fault+0x36d/0xa20 mm/memory.c:6718
       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_to_user arch/x86/include/asm/uaccess_64.h:147 [inline]
       copy_to_user_iter lib/iov_iter.c:25 [inline]
       iterate_iovec include/linux/iov_iter.h:52 [inline]
       iterate_and_advance2 include/linux/iov_iter.h:304 [inline]
       iterate_and_advance include/linux/iov_iter.h:330 [inline]
       _copy_to_iter+0x4c5/0x1720 lib/iov_iter.c:197
       copy_to_iter include/linux/uio.h:220 [inline]
       simple_copy_to_iter+0x46/0x90 net/core/datagram.c:521
       __skb_datagram_iter+0x129/0x900 net/core/datagram.c:402
       skb_copy_datagram_iter+0xa5/0x270 net/core/datagram.c:535
       skb_copy_datagram_msg include/linux/skbuff.h:4243 [inline]
       __unix_dgram_recvmsg+0x44b/0xc30 net/unix/af_unix.c:2629
       unix_dgram_recvmsg net/unix/af_unix.c:2686 [inline]
       unix_seqpacket_recvmsg+0x119/0x160 net/unix/af_unix.c:2553
       sock_recvmsg_nosec net/socket.c:1137 [inline]
       sock_recvmsg+0x1a4/0x1f0 net/socket.c:1159
       sock_read_iter+0x2c6/0x3c0 net/socket.c:1229
       do_iter_readv_writev+0x60d/0x920 fs/read_write.c:827
       vfs_readv+0x4d3/0x8d0 fs/read_write.c:1020
       do_readv+0x28a/0x340 fs/read_write.c:1082
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x10b/0xf80 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_INET6 --> &mm->mmap_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(&mm->mmap_lock);
                               lock(sk_lock-AF_INET6);
                               lock(&mm->mmap_lock);
  lock(fs_reclaim);

 *** DEADLOCK ***

2 locks held by dhcpcd/5271:
 #0: ffff88803600a7f0 (&u->iolock){+.+.}-{4:4}, at: __unix_dgram_recvmsg+0x255/0xc30 net/unix/af_unix.c:2584
 #1: ffff888039499bb8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:611 [inline]
 #1: ffff888039499bb8 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:441 [inline]
 #1: ffff888039499bb8 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x35/0x6f0 mm/mmap_lock.c:501

stack backtrace:
CPU: 1 UID: 101 PID: 5271 Comm: dhcpcd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 __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:4325 [inline]
 fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4339
 might_alloc include/linux/sched/mm.h:317 [inline]
 prepare_alloc_pages+0x166/0x5f0 mm/page_alloc.c:4995
 __alloc_frozen_pages_noprof+0x19a/0x2bc0 mm/page_alloc.c:5215
 alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490
 folio_alloc_mpol_noprof+0x36/0x260 mm/mempolicy.c:2509
 vma_alloc_folio_noprof+0xed/0x1d0 mm/mempolicy.c:2544
 folio_prealloc mm/memory.c:1193 [inline]
 wp_page_copy mm/memory.c:3859 [inline]
 do_wp_page+0x1ee1/0x4350 mm/memory.c:4320
 handle_pte_fault mm/memory.c:6427 [inline]
 __handle_mm_fault+0x1ab6/0x2a00 mm/memory.c:6549
 handle_mm_fault+0x36d/0xa20 mm/memory.c:6718
 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
RIP: 0010:rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:74
Code: 9b 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:ffffc90005767640 EFLAGS: 00050202
RAX: 0000000000000001 RBX: 0000000000001c48 RCX: 0000000000001348
RDX: 0000000000000001 RSI: ffff888021f94918 RDI: 000055c684ec2000
RBP: ffffc90005767d60 R08: 0000000000000000 R09: ffffed10043f2b8b
R10: ffff888021f95c5f R11: 0000000000000000 R12: ffff888021f94018
R13: 0000000000000000 R14: 000055c684ec1700 R15: 0000000000001c48
 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline]
 copy_to_user_iter lib/iov_iter.c:25 [inline]
 iterate_iovec include/linux/iov_iter.h:52 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:304 [inline]
 iterate_and_advance include/linux/iov_iter.h:330 [inline]
 _copy_to_iter+0x4c5/0x1720 lib/iov_iter.c:197
 copy_to_iter include/linux/uio.h:220 [inline]
 simple_copy_to_iter+0x46/0x90 net/core/datagram.c:521
 __skb_datagram_iter+0x129/0x900 net/core/datagram.c:402
 skb_copy_datagram_iter+0xa5/0x270 net/core/datagram.c:535
 skb_copy_datagram_msg include/linux/skbuff.h:4243 [inline]
 __unix_dgram_recvmsg+0x44b/0xc30 net/unix/af_unix.c:2629
 unix_dgram_recvmsg net/unix/af_unix.c:2686 [inline]
 unix_seqpacket_recvmsg+0x119/0x160 net/unix/af_unix.c:2553
 sock_recvmsg_nosec net/socket.c:1137 [inline]
 sock_recvmsg+0x1a4/0x1f0 net/socket.c:1159
 sock_read_iter+0x2c6/0x3c0 net/socket.c:1229
 do_iter_readv_writev+0x60d/0x920 fs/read_write.c:827
 vfs_readv+0x4d3/0x8d0 fs/read_write.c:1020
 do_readv+0x28a/0x340 fs/read_write.c:1082
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f051f691407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fffe965f300 EFLAGS: 00000202 ORIG_RAX: 0000000000000013
RAX: ffffffffffffffda RBX: 00007f051f607780 RCX: 00007f051f691407
RDX: 0000000000000002 RSI: 00007fffe965f350 RDI: 000000000000000a
RBP: 00007fffe966f860 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000001c48
R13: 000055c684ece390 R14: 0000000000000000 R15: 00007fffe966f850
 </TASK>
----------------
Code disassembly (best guess):
   0:	9b                   	fwait
   1:	04 00                	add    $0x0,%al
   3:	66 66 2e 0f 1f 84 00 	data16 cs nopw 0x0(%rax,%rax,1)
   a:	00 00 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

Crashes (1857):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/06 02:04 upstream 9207d47f966b 26da2c66 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root possible deadlock in lock_mm_and_find_vma
2026/05/05 01:52 upstream c7e4e4d5f7dc a898ba9c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in lock_mm_and_find_vma
2026/04/27 22:20 upstream 254f49634ee1 ce741359 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root possible deadlock in lock_mm_and_find_vma
2026/02/22 14:48 upstream 32a92f8c8932 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto possible deadlock in lock_mm_and_find_vma
2026/04/22 14:08 upstream 6596a02b2078 0e869ba2 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in lock_mm_and_find_vma
2026/05/31 15:41 net 78ef59e7a645 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/31 14:08 net 78ef59e7a645 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/31 09:42 net 78ef59e7a645 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/31 07:58 net 78ef59e7a645 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/30 21:45 net 78ef59e7a645 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/30 15:12 net 78ef59e7a645 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/30 08:02 net 78ef59e7a645 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/29 13:43 net 422b5233b607 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/29 11:27 net f14fe6395a8b 4624854e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/28 23:27 net 031f1592e592 9a5a7e5e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/28 20:50 net 031f1592e592 9a5a7e5e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/28 19:22 net 031f1592e592 9a5a7e5e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/28 17:29 net 031f1592e592 9a5a7e5e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/28 14:19 net 031f1592e592 9a5a7e5e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/28 09:39 net 8ba68464e478 4c36e7e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/28 07:16 net 8ba68464e478 4c36e7e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/28 03:19 net 8ba68464e478 4c36e7e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/27 23:13 net dd433671fef3 4c36e7e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/27 21:58 net dd433671fef3 769cbc61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/27 16:28 net dd433671fef3 769cbc61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/06/01 00:06 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/31 21:00 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/31 18:18 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/31 16:55 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/31 11:03 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/31 07:38 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/31 06:14 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/31 02:56 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/31 01:49 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/30 19:15 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/30 17:35 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/30 09:30 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/30 05:42 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/30 03:26 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/30 00:21 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/29 20:57 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/29 19:17 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/29 17:20 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/29 00:54 net-next 9a82e387e27a 4624854e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/28 21:54 net-next 0cf905cb9a12 9a5a7e5e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/28 18:55 net-next 0cf905cb9a12 9a5a7e5e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/28 08:28 net-next 56ed77ff6022 4c36e7e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/28 05:22 net-next 56ed77ff6022 4c36e7e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/27 21:43 net-next aa064a614efc 769cbc61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/27 15:08 net-next aa064a614efc 769cbc61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in lock_mm_and_find_vma
2026/05/29 22:55 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 4b4362973b6f 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in lock_mm_and_find_vma
* Struck through repros no longer work on HEAD.