Search Results (18614 CVEs found)

CVE Vendors Products Updated CVSS v3.1
CVE-2022-50656 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: nfc: pn533: Clear nfc_target before being used Fix a slab-out-of-bounds read that occurs in nla_put() called from nfc_genl_send_target() when target->sensb_res_len, which is duplicated from an nfc_target in pn533, is too large as the nfc_target is not properly initialized and retains garbage values. Clear nfc_targets with memset() before they are used. Found by a modified version of syzkaller. BUG: KASAN: slab-out-of-bounds in nla_put Call Trace: memcpy nla_put nfc_genl_dump_targets genl_lock_dumpit netlink_dump __netlink_dump_start genl_family_rcv_msg_dumpit genl_rcv_msg netlink_rcv_skb genl_rcv netlink_unicast netlink_sendmsg sock_sendmsg ____sys_sendmsg ___sys_sendmsg __sys_sendmsg do_syscall_64
CVE-2025-68178 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: fix possible deadlock while configuring policy Following deadlock can be triggered easily by lockdep: WARNING: possible circular locking dependency detected 6.17.0-rc3-00124-ga12c2658ced0 #1665 Not tainted ------------------------------------------------------ check/1334 is trying to acquire lock: ff1100011d9d0678 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_unregister_queue+0x53/0x180 but task is already holding lock: ff1100011d9d00e0 (&q->q_usage_counter(queue)#3){++++}-{0:0}, at: del_gendisk+0xba/0x110 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&q->q_usage_counter(queue)#3){++++}-{0:0}: blk_queue_enter+0x40b/0x470 blkg_conf_prep+0x7b/0x3c0 tg_set_limit+0x10a/0x3e0 cgroup_file_write+0xc6/0x420 kernfs_fop_write_iter+0x189/0x280 vfs_write+0x256/0x490 ksys_write+0x83/0x190 __x64_sys_write+0x21/0x30 x64_sys_call+0x4608/0x4630 do_syscall_64+0xdb/0x6b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #1 (&q->rq_qos_mutex){+.+.}-{4:4}: __mutex_lock+0xd8/0xf50 mutex_lock_nested+0x2b/0x40 wbt_init+0x17e/0x280 wbt_enable_default+0xe9/0x140 blk_register_queue+0x1da/0x2e0 __add_disk+0x38c/0x5d0 add_disk_fwnode+0x89/0x250 device_add_disk+0x18/0x30 virtblk_probe+0x13a3/0x1800 virtio_dev_probe+0x389/0x610 really_probe+0x136/0x620 __driver_probe_device+0xb3/0x230 driver_probe_device+0x2f/0xe0 __driver_attach+0x158/0x250 bus_for_each_dev+0xa9/0x130 driver_attach+0x26/0x40 bus_add_driver+0x178/0x3d0 driver_register+0x7d/0x1c0 __register_virtio_driver+0x2c/0x60 virtio_blk_init+0x6f/0xe0 do_one_initcall+0x94/0x540 kernel_init_freeable+0x56a/0x7b0 kernel_init+0x2b/0x270 ret_from_fork+0x268/0x4c0 ret_from_fork_asm+0x1a/0x30 -> #0 (&q->sysfs_lock){+.+.}-{4:4}: __lock_acquire+0x1835/0x2940 lock_acquire+0xf9/0x450 __mutex_lock+0xd8/0xf50 mutex_lock_nested+0x2b/0x40 blk_unregister_queue+0x53/0x180 __del_gendisk+0x226/0x690 del_gendisk+0xba/0x110 sd_remove+0x49/0xb0 [sd_mod] device_remove+0x87/0xb0 device_release_driver_internal+0x11e/0x230 device_release_driver+0x1a/0x30 bus_remove_device+0x14d/0x220 device_del+0x1e1/0x5a0 __scsi_remove_device+0x1ff/0x2f0 scsi_remove_device+0x37/0x60 sdev_store_delete+0x77/0x100 dev_attr_store+0x1f/0x40 sysfs_kf_write+0x65/0x90 kernfs_fop_write_iter+0x189/0x280 vfs_write+0x256/0x490 ksys_write+0x83/0x190 __x64_sys_write+0x21/0x30 x64_sys_call+0x4608/0x4630 do_syscall_64+0xdb/0x6b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e other info that might help us debug this: Chain exists of: &q->sysfs_lock --> &q->rq_qos_mutex --> &q->q_usage_counter(queue)#3 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->q_usage_counter(queue)#3); lock(&q->rq_qos_mutex); lock(&q->q_usage_counter(queue)#3); lock(&q->sysfs_lock); Root cause is that queue_usage_counter is grabbed with rq_qos_mutex held in blkg_conf_prep(), while queue should be freezed before rq_qos_mutex from other context. The blk_queue_enter() from blkg_conf_prep() is used to protect against policy deactivation, which is already protected with blkcg_mutex, hence convert blk_queue_enter() to blkcg_mutex to fix this problem. Meanwhile, consider that blkcg_mutex is held after queue is freezed from policy deactivation, also convert blkg_alloc() to use GFP_NOIO.
CVE-2022-50657 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: riscv: mm: add missing memcpy in kasan_init Hi Atish, It seems that the panic is due to the missing memcpy during kasan_init. Could you please check whether this patch is helpful? When doing kasan_populate, the new allocated base_pud/base_p4d should contain kasan_early_shadow_{pud, p4d}'s content. Add the missing memcpy to avoid page fault when read/write kasan shadow region. Tested on: - qemu with sv57 and CONFIG_KASAN on. - qemu with sv48 and CONFIG_KASAN on.
CVE-2022-50659 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: hwrng: geode - Fix PCI device refcount leak for_each_pci_dev() is implemented by pci_get_device(). The comment of pci_get_device() says that it will increase the reference count for the returned pci_dev and also decrease the reference count for the input pci_dev @from if it is not NULL. If we break for_each_pci_dev() loop with pdev not NULL, we need to call pci_dev_put() to decrease the reference count. We add a new struct 'amd_geode_priv' to record pointer of the pci_dev and membase, and then add missing pci_dev_put() for the normal and error path.
CVE-2022-50660 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: wifi: ipw2200: fix memory leak in ipw_wdev_init() In the error path of ipw_wdev_init(), exception value is returned, and the memory applied for in the function is not released. Also the memory is not released in ipw_pci_probe(). As a result, memory leakage occurs. So memory release needs to be added to the error path of ipw_wdev_init().
CVE-2022-50666 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: RDMA/siw: Fix QP destroy to wait for all references dropped. Delay QP destroy completion until all siw references to QP are dropped. The calling RDMA core will free QP structure after successful return from siw_qp_destroy() call, so siw must not hold any remaining reference to the QP upon return. A use-after-free was encountered in xfstest generic/460, while testing NFSoRDMA. Here, after a TCP connection drop by peer, the triggered siw_cm_work_handler got delayed until after QP destroy call, referencing a QP which has already freed.
CVE-2022-50668 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: ext4: fix deadlock due to mbcache entry corruption When manipulating xattr blocks, we can deadlock infinitely looping inside ext4_xattr_block_set() where we constantly keep finding xattr block for reuse in mbcache but we are unable to reuse it because its reference count is too big. This happens because cache entry for the xattr block is marked as reusable (e_reusable set) although its reference count is too big. When this inconsistency happens, this inconsistent state is kept indefinitely and so ext4_xattr_block_set() keeps retrying indefinitely. The inconsistent state is caused by non-atomic update of e_reusable bit. e_reusable is part of a bitfield and e_reusable update can race with update of e_referenced bit in the same bitfield resulting in loss of one of the updates. Fix the problem by using atomic bitops instead. This bug has been around for many years, but it became *much* easier to hit after commit 65f8b80053a1 ("ext4: fix race when reusing xattr blocks").
CVE-2022-50669 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: misc: ocxl: fix possible name leak in ocxl_file_register_afu() If device_register() returns error in ocxl_file_register_afu(), the name allocated by dev_set_name() need be freed. As comment of device_register() says, it should use put_device() to give up the reference in the error path. So fix this by calling put_device(), then the name can be freed in kobject_cleanup(), and info is freed in info_release().
CVE-2022-50672 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: mailbox: zynq-ipi: fix error handling while device_register() fails If device_register() fails, it has two issues: 1. The name allocated by dev_set_name() is leaked. 2. The parent of device is not NULL, device_unregister() is called in zynqmp_ipi_free_mboxes(), it will lead a kernel crash because of removing not added device. Call put_device() to give up the reference, so the name is freed in kobject_cleanup(). Add device registered check in zynqmp_ipi_free_mboxes() to avoid null-ptr-deref.
CVE-2023-53992 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: ocb: don't leave if not joined If there's no OCB state, don't ask the driver/mac80211 to leave, since that's just confusing. Since set/clear the chandef state, that's a simple check.
CVE-2023-53993 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: PCI/DOE: Fix memory leak with CONFIG_DEBUG_OBJECTS=y After a pci_doe_task completes, its work_struct needs to be destroyed to avoid a memory leak with CONFIG_DEBUG_OBJECTS=y.
CVE-2023-53787 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: regulator: da9063: fix null pointer deref with partial DT config When some of the da9063 regulators do not have corresponding DT nodes a null pointer dereference occurs on boot because such regulators have no init_data causing the pointers calculated in da9063_check_xvp_constraints() to be invalid. Do not dereference them in this case.
CVE-2022-50673 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: ext4: fix use-after-free in ext4_orphan_cleanup I caught a issue as follows: ================================================================== BUG: KASAN: use-after-free in __list_add_valid+0x28/0x1a0 Read of size 8 at addr ffff88814b13f378 by task mount/710 CPU: 1 PID: 710 Comm: mount Not tainted 6.1.0-rc3-next #370 Call Trace: <TASK> dump_stack_lvl+0x73/0x9f print_report+0x25d/0x759 kasan_report+0xc0/0x120 __asan_load8+0x99/0x140 __list_add_valid+0x28/0x1a0 ext4_orphan_cleanup+0x564/0x9d0 [ext4] __ext4_fill_super+0x48e2/0x5300 [ext4] ext4_fill_super+0x19f/0x3a0 [ext4] get_tree_bdev+0x27b/0x450 ext4_get_tree+0x19/0x30 [ext4] vfs_get_tree+0x49/0x150 path_mount+0xaae/0x1350 do_mount+0xe2/0x110 __x64_sys_mount+0xf0/0x190 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK> [...] ================================================================== Above issue may happen as follows: ------------------------------------- ext4_fill_super ext4_orphan_cleanup --- loop1: assume last_orphan is 12 --- list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan) ext4_truncate --> return 0 ext4_inode_attach_jinode --> return -ENOMEM iput(inode) --> free inode<12> --- loop2: last_orphan is still 12 --- list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan); // use inode<12> and trigger UAF To solve this issue, we need to propagate the return value of ext4_inode_attach_jinode() appropriately.
CVE-2023-53795 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: iommufd: IOMMUFD_DESTROY should not increase the refcount syzkaller found a race where IOMMUFD_DESTROY increments the refcount: obj = iommufd_get_object(ucmd->ictx, cmd->id, IOMMUFD_OBJ_ANY); if (IS_ERR(obj)) return PTR_ERR(obj); iommufd_ref_to_users(obj); /* See iommufd_ref_to_users() */ if (!iommufd_object_destroy_user(ucmd->ictx, obj)) As part of the sequence to join the two existing primitives together. Allowing the refcount the be elevated without holding the destroy_rwsem violates the assumption that all temporary refcount elevations are protected by destroy_rwsem. Racing IOMMUFD_DESTROY with iommufd_object_destroy_user() will cause spurious failures: WARNING: CPU: 0 PID: 3076 at drivers/iommu/iommufd/device.c:477 iommufd_access_destroy+0x18/0x20 drivers/iommu/iommufd/device.c:478 Modules linked in: CPU: 0 PID: 3076 Comm: syz-executor.0 Not tainted 6.3.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023 RIP: 0010:iommufd_access_destroy+0x18/0x20 drivers/iommu/iommufd/device.c:477 Code: e8 3d 4e 00 00 84 c0 74 01 c3 0f 0b c3 0f 1f 44 00 00 f3 0f 1e fa 48 89 fe 48 8b bf a8 00 00 00 e8 1d 4e 00 00 84 c0 74 01 c3 <0f> 0b c3 0f 1f 44 00 00 41 57 41 56 41 55 4c 8d ae d0 00 00 00 41 RSP: 0018:ffffc90003067e08 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff888109ea0300 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00000000ffffffff RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88810bbb3500 R10: ffff88810bbb3e48 R11: 0000000000000000 R12: ffffc90003067e88 R13: ffffc90003067ea8 R14: ffff888101249800 R15: 00000000fffffffe FS: 00007ff7254fe6c0(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555557262da8 CR3: 000000010a6fd000 CR4: 0000000000350ef0 Call Trace: <TASK> iommufd_test_create_access drivers/iommu/iommufd/selftest.c:596 [inline] iommufd_test+0x71c/0xcf0 drivers/iommu/iommufd/selftest.c:813 iommufd_fops_ioctl+0x10f/0x1b0 drivers/iommu/iommufd/main.c:337 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x84/0xc0 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The solution is to not increment the refcount on the IOMMUFD_DESTROY path at all. Instead use the xa_lock to serialize everything. The refcount check == 1 and xa_erase can be done under a single critical region. This avoids the need for any refcount incrementing. It has the downside that if userspace races destroy with other operations it will get an EBUSY instead of waiting, but this is kind of racing is already dangerous.
CVE-2022-50676 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: net: rds: don't hold sock lock when cancelling work from rds_tcp_reset_callbacks() syzbot is reporting lockdep warning at rds_tcp_reset_callbacks() [1], for commit ac3615e7f3cffe2a ("RDS: TCP: Reduce code duplication in rds_tcp_reset_callbacks()") added cancel_delayed_work_sync() into a section protected by lock_sock() without realizing that rds_send_xmit() might call lock_sock(). We don't need to protect cancel_delayed_work_sync() using lock_sock(), for even if rds_{send,recv}_worker() re-queued this work while __flush_work() from cancel_delayed_work_sync() was waiting for this work to complete, retried rds_{send,recv}_worker() is no-op due to the absence of RDS_CONN_UP bit.
CVE-2022-50677 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: ipmi: fix use after free in _ipmi_destroy_user() The intf_free() function frees the "intf" pointer so we cannot dereference it again on the next line.
CVE-2022-50679 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: i40e: Fix DMA mappings leak During reallocation of RX buffers, new DMA mappings are created for those buffers. steps for reproduction: while : do for ((i=0; i<=8160; i=i+32)) do ethtool -G enp130s0f0 rx $i tx $i sleep 0.5 ethtool -g enp130s0f0 done done This resulted in crash: i40e 0000:01:00.1: Unable to allocate memory for the Rx descriptor ring, size=65536 Driver BUG WARNING: CPU: 0 PID: 4300 at net/core/xdp.c:141 xdp_rxq_info_unreg+0x43/0x50 Call Trace: i40e_free_rx_resources+0x70/0x80 [i40e] i40e_set_ringparam+0x27c/0x800 [i40e] ethnl_set_rings+0x1b2/0x290 genl_family_rcv_msg_doit.isra.15+0x10f/0x150 genl_family_rcv_msg+0xb3/0x160 ? rings_fill_reply+0x1a0/0x1a0 genl_rcv_msg+0x47/0x90 ? genl_family_rcv_msg+0x160/0x160 netlink_rcv_skb+0x4c/0x120 genl_rcv+0x24/0x40 netlink_unicast+0x196/0x230 netlink_sendmsg+0x204/0x3d0 sock_sendmsg+0x4c/0x50 __sys_sendto+0xee/0x160 ? handle_mm_fault+0xbe/0x1e0 ? syscall_trace_enter+0x1d3/0x2c0 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x5b/0x1a0 entry_SYSCALL_64_after_hwframe+0x65/0xca RIP: 0033:0x7f5eac8b035b Missing register, driver bug WARNING: CPU: 0 PID: 4300 at net/core/xdp.c:119 xdp_rxq_info_unreg_mem_model+0x69/0x140 Call Trace: xdp_rxq_info_unreg+0x1e/0x50 i40e_free_rx_resources+0x70/0x80 [i40e] i40e_set_ringparam+0x27c/0x800 [i40e] ethnl_set_rings+0x1b2/0x290 genl_family_rcv_msg_doit.isra.15+0x10f/0x150 genl_family_rcv_msg+0xb3/0x160 ? rings_fill_reply+0x1a0/0x1a0 genl_rcv_msg+0x47/0x90 ? genl_family_rcv_msg+0x160/0x160 netlink_rcv_skb+0x4c/0x120 genl_rcv+0x24/0x40 netlink_unicast+0x196/0x230 netlink_sendmsg+0x204/0x3d0 sock_sendmsg+0x4c/0x50 __sys_sendto+0xee/0x160 ? handle_mm_fault+0xbe/0x1e0 ? syscall_trace_enter+0x1d3/0x2c0 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x5b/0x1a0 entry_SYSCALL_64_after_hwframe+0x65/0xca RIP: 0033:0x7f5eac8b035b This was caused because of new buffers with different RX ring count should substitute older ones, but those buffers were freed in i40e_configure_rx_ring and reallocated again with i40e_alloc_rx_bi, thus kfree on rx_bi caused leak of already mapped DMA. Fix this by reallocating ZC with rx_bi_zc struct when BPF program loads. Additionally reallocate back to rx_bi when BPF program unloads. If BPF program is loaded/unloaded and XSK pools are created, reallocate RX queues accordingly in XSP_SETUP_XSK_POOL handler.
CVE-2023-53996 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: x86/sev: Make enc_dec_hypercall() accept a size instead of npages enc_dec_hypercall() accepted a page count instead of a size, which forced its callers to round up. As a result, non-page aligned vaddrs caused pages to be spuriously marked as decrypted via the encryption status hypercall, which in turn caused consistent corruption of pages during live migration. Live migration requires accurate encryption status information to avoid migrating pages from the wrong perspective.
CVE-2022-50697 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: mrp: introduce active flags to prevent UAF when applicant uninit The caller of del_timer_sync must prevent restarting of the timer, If we have no this synchronization, there is a small probability that the cancellation will not be successful. And syzbot report the fellowing crash: ================================================================== BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:929 [inline] BUG: KASAN: use-after-free in enqueue_timer+0x18/0xa4 kernel/time/timer.c:605 Write at addr f9ff000024df6058 by task syz-fuzzer/2256 Pointer tag: [f9], memory tag: [fe] CPU: 1 PID: 2256 Comm: syz-fuzzer Not tainted 6.1.0-rc5-syzkaller-00008- ge01d50cbd6ee #0 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace.part.0+0xe0/0xf0 arch/arm64/kernel/stacktrace.c:156 dump_backtrace arch/arm64/kernel/stacktrace.c:162 [inline] show_stack+0x18/0x40 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x68/0x84 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x1a8/0x4a0 mm/kasan/report.c:395 kasan_report+0x94/0xb4 mm/kasan/report.c:495 __do_kernel_fault+0x164/0x1e0 arch/arm64/mm/fault.c:320 do_bad_area arch/arm64/mm/fault.c:473 [inline] do_tag_check_fault+0x78/0x8c arch/arm64/mm/fault.c:749 do_mem_abort+0x44/0x94 arch/arm64/mm/fault.c:825 el1_abort+0x40/0x60 arch/arm64/kernel/entry-common.c:367 el1h_64_sync_handler+0xd8/0xe4 arch/arm64/kernel/entry-common.c:427 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:576 hlist_add_head include/linux/list.h:929 [inline] enqueue_timer+0x18/0xa4 kernel/time/timer.c:605 mod_timer+0x14/0x20 kernel/time/timer.c:1161 mrp_periodic_timer_arm net/802/mrp.c:614 [inline] mrp_periodic_timer+0xa0/0xc0 net/802/mrp.c:627 call_timer_fn.constprop.0+0x24/0x80 kernel/time/timer.c:1474 expire_timers+0x98/0xc4 kernel/time/timer.c:1519 To fix it, we can introduce a new active flags to make sure the timer will not restart.
CVE-2023-53809 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: l2tp: Avoid possible recursive deadlock in l2tp_tunnel_register() When a file descriptor of pppol2tp socket is passed as file descriptor of UDP socket, a recursive deadlock occurs in l2tp_tunnel_register(). This situation is reproduced by the following program: int main(void) { int sock; struct sockaddr_pppol2tp addr; sock = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP); if (sock < 0) { perror("socket"); return 1; } addr.sa_family = AF_PPPOX; addr.sa_protocol = PX_PROTO_OL2TP; addr.pppol2tp.pid = 0; addr.pppol2tp.fd = sock; addr.pppol2tp.addr.sin_family = PF_INET; addr.pppol2tp.addr.sin_port = htons(0); addr.pppol2tp.addr.sin_addr.s_addr = inet_addr("192.168.0.1"); addr.pppol2tp.s_tunnel = 1; addr.pppol2tp.s_session = 0; addr.pppol2tp.d_tunnel = 0; addr.pppol2tp.d_session = 0; if (connect(sock, (const struct sockaddr *)&addr, sizeof(addr)) < 0) { perror("connect"); return 1; } return 0; } This program causes the following lockdep warning: ============================================ WARNING: possible recursive locking detected 6.2.0-rc5-00205-gc96618275234 #56 Not tainted -------------------------------------------- repro/8607 is trying to acquire lock: ffff8880213c8130 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: l2tp_tunnel_register+0x2b7/0x11c0 but task is already holding lock: ffff8880213c8130 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: pppol2tp_connect+0xa82/0x1a30 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(sk_lock-AF_PPPOX); lock(sk_lock-AF_PPPOX); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by repro/8607: #0: ffff8880213c8130 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: pppol2tp_connect+0xa82/0x1a30 stack backtrace: CPU: 0 PID: 8607 Comm: repro Not tainted 6.2.0-rc5-00205-gc96618275234 #56 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x100/0x178 __lock_acquire.cold+0x119/0x3b9 ? lockdep_hardirqs_on_prepare+0x410/0x410 lock_acquire+0x1e0/0x610 ? l2tp_tunnel_register+0x2b7/0x11c0 ? lock_downgrade+0x710/0x710 ? __fget_files+0x283/0x3e0 lock_sock_nested+0x3a/0xf0 ? l2tp_tunnel_register+0x2b7/0x11c0 l2tp_tunnel_register+0x2b7/0x11c0 ? sprintf+0xc4/0x100 ? l2tp_tunnel_del_work+0x6b0/0x6b0 ? debug_object_deactivate+0x320/0x320 ? lockdep_init_map_type+0x16d/0x7a0 ? lockdep_init_map_type+0x16d/0x7a0 ? l2tp_tunnel_create+0x2bf/0x4b0 ? l2tp_tunnel_create+0x3c6/0x4b0 pppol2tp_connect+0x14e1/0x1a30 ? pppol2tp_put_sk+0xd0/0xd0 ? aa_sk_perm+0x2b7/0xa80 ? aa_af_perm+0x260/0x260 ? bpf_lsm_socket_connect+0x9/0x10 ? pppol2tp_put_sk+0xd0/0xd0 __sys_connect_file+0x14f/0x190 __sys_connect+0x133/0x160 ? __sys_connect_file+0x190/0x190 ? lockdep_hardirqs_on+0x7d/0x100 ? ktime_get_coarse_real_ts64+0x1b7/0x200 ? ktime_get_coarse_real_ts64+0x147/0x200 ? __audit_syscall_entry+0x396/0x500 __x64_sys_connect+0x72/0xb0 do_syscall_64+0x38/0xb0 entry_SYSCALL_64_after_hwframe+0x63/0xcd This patch fixes the issue by getting/creating the tunnel before locking the pppol2tp socket.