CVE Database

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Fix error path at svm_migrate_copy_to_ram If page migration from device to sys ram fails for some reasons driver needs release and unlock allocated system pages. To do that driver should use page physical address, or pfn, then get struct page*. Current driver uses dma address(for adev) that is not correct with IOMMU enabled, or even in general. The patch releases and unlocks allocated system pages based on where migration failed by struct page* of sys ram pages. Also dma_unmap correspodent system ram pages at error path.

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Fix the case that vm range is hole at svm_migrate_copy_to_vram When migration vm range is hole at cpu side(MIGRATE_PFN_MIGRATE set + MIGRATE_PFN_VALID unset) driver still allocates device pages. There is no dma map of src pages and migration. j is 0 and svm_migrate_copy_memory_gart() will return an uninitialized r. That can trigger out_free_vram_pages to drop all VRAM just set up. Initialize r and only call the last svm_migrate_copy_memory_gart if j > 0. Current code postponed the last page to the final copy. This patch flushes on the last page when reach to the end of current drm_buddy_block; avoids another svm_migrate_copy_memory_gart.

In the Linux kernel, the following vulnerability has been resolved: drm/sysfb: ofdrm: Fix integer overflow in fb_size calculation The framebuffer size calculation `fb_size = linebytes * height` can overflow when both values are large (e.g., 46341 * 46341 > INT_MAX). Since linebytes and height are both int types, the multiplication is performed as int * int, which results in undefined behavior on overflow. Use check_mul_overflow() to detect and prevent this overflow, consistent with the approach used in simpledrm.c and corebootdrm.c.

In the Linux kernel, the following vulnerability has been resolved: drm/pagemap: Fix folio allocation fallback and use-after-put drm_pagemap_migrate_populate_ram_pfn() had two issues when populating RAM PFNs with higher-order folios: 1. The higher-order vma_alloc_folio()/folio_alloc() calls did not pass __GFP_NOWARN, so a THP allocation failure under memory pressure would spam the kernel log, and there was no fallback path despite a TODO comment stating one was needed. Add __GFP_NOWARN to the higher-order allocation and, on failure, fall back to order-0 allocations for the entire range originally covered by the failed higher-order allocation, leaving MIGRATE_PFN_COMPOUND unset for those PFNs. 2. In the free_pages error path, order was computed via folio_order(page_folio(page)) *after* put_page(page) had already dropped the reference, resulting in a use-after-free/put when that was the last reference on the page. Compute order before releasing the page. Introducing the fallback in 1. also requires the source page array handed to ->copy_to_ram() to be built differently. Both callers only populated the entry at the head of each source folio, relying on the copy callback to derive the rest of the folio from the order recorded in the matching drm_pagemap_addr. Once the destination has been demoted to order-0 folios the drm_pagemap_addr entries are per-page, so a source page is needed for every one of them; leaving them NULL makes the copy callback stop after the first page and the remainder of the range is never copied. The source folio is only split later, by migrate_vma_pages() / migrate_device_pages(), so its order cannot be used to detect the demotion - test the destination for MIGRATE_PFN_COMPOUND instead. Factor the array population out into drm_pagemap_migrate_populate_src_pages() and use it from both drm_pagemap_evict_to_ram() and __drm_pagemap_migrate_to_ram().

In the Linux kernel, the following vulnerability has been resolved: drm/nouveau/dmem: fix mismatched DMA unmap size for large folios Device-private THP migration maps migration buffers with page_size() and records that length in dma_info->size. For a compound folio page_size() is PAGE_SIZE << order, but two teardown sites still pass a literal PAGE_SIZE to dma_unmap_page(): - nouveau_dmem_migrate_to_ram() on the success path, and - nouveau_dmem_migrate_copy_one() on the copy-error path. For an order > 0 folio this unmaps less than was mapped, leaking the remainder of the IOMMU/IOVA mapping. The other unmap sites, in nouveau_dmem_migrate_chunk() and nouveau_dmem_evict_chunk(), already use the saved size; use it here too.

In the Linux kernel, the following vulnerability has been resolved: drm/nouveau: unsubscribe the channel-kill event before the fence context nouveau_channel_del() tears the fence context down first and only drops the channel-kill subscription later, in the middle of the nvif object teardown: if (chan->fence) nouveau_fence(chan->cli->drm)->context_del(chan); ... nvif_object_dtor(&chan->vram); nvif_event_dtor(&chan->kill); The subscribed handler is nouveau_channel_killed(), which calls nouveau_channel_kill() and from there nouveau_fence_context_kill() on chan->fence. A kill event delivered in that window takes fctx->lock and walks fctx->pending on a fence context that context_del() has already freed. Nothing reaches this below Fermi today, because the subscription is gated on FERMI_CHANNEL_GPFIFO and nothing kills a channel there. On Fermi and newer the window is real but narrow, since a kill has to land exactly while the channel is being destroyed. That is reason enough on its own, which is why this carries a Fixes: tag. The last patch in this series subscribes Tesla channels as well; nothing kills those today, so it does not widen the exposure now, but it is the groundwork for a recovery path that would, and the ordering is better fixed before that lands than alongside it. Drop the subscription before anything it depends on is torn down.

In the Linux kernel, the following vulnerability has been resolved: drm/nouveau/uvmm: fix premature region free on failed OP_UNMAP_SPARSE In nouveau_uvmm_bind_job_submit()'s OP_UNMAP_SPARSE arm, op->reg is set from nouveau_uvma_region_find(), which only looks the region up and takes no reference; a region's sole reference is its membership in uvmm->region_mt. Two failure paths leave op->reg set: the -ENOENT check when the region is busy, and the drm_gpuvm_sm_unmap_ops_create() failure. The sibling nouveau_uvmm_sm_unmap_prepare() failure just below clears op->reg; these two do not. unwind_continue steps back one op, so the failing op is skipped by the unwind loop and its op->reg stays set. nouveau_uvmm_bind_job_cleanup() then enters its if (op->reg) branch and calls nouveau_uvma_region_remove() and nouveau_uvma_region_put() on it, dropping the tree's sole reference and freeing a region this job never created. The comment above the cleanup loop documents the broken invariant: op->reg must be NULL on submit failure. This frees a live region on an unrelated failure, reachable single-job when drm_gpuvm_sm_unmap_ops_create() returns -ENOMEM; if another job owns the same region, its cleanup then removes and puts the freed region, a use-after-free. Clear op->reg on both failure paths.

In the Linux kernel, the following vulnerability has been resolved: bpf: Disable preemption in bpf_get_stackid The get_perf_callchain call needs disabled preemption plus we need it disabled as long as we access its returned trace entries buffer. Note the bpf_get_stackid_pe function is executed already with preemption disabled.

In the Linux kernel, the following vulnerability has been resolved: PCI: Allow per function PCI slots to fix slot reset on s390 On s390 systems, which use a machine level hypervisor, PCI devices are always accessed through a form of PCI pass-through which fundamentally operates on a per PCI function granularity. This is also reflected in the s390 PCI hotplug driver which creates hotplug slots for individual PCI functions. Its reset_slot() function, which is a wrapper for zpci_hot_reset_device(), thus also resets individual functions. Currently, the pci_create_slot() assigns the same pci_slot object to multifunction devices. This approach worked fine on s390 systems that only exposed virtual functions as individual PCI domains to the operating system. Since commit 44510d6fa0c0 ("s390/pci: Handling multifunctions") s390 supports exposing the topology of multifunction PCI devices by grouping them in a shared PCI domain. This creates a problem when resetting a function through the hotplug driver's slot_reset() interface. When attempting to reset a function through the hotplug driver, the shared slot assignment causes the wrong function to be reset instead of the intended one. It also leaks memory as we do create a pci_slot object for the function, but don't correctly free it in pci_slot_release(). Add a flag for struct pci_slot to allow per function PCI slots for functions managed through a hypervisor, which exposes individual PCI functions while retaining the topology. Since we can use all 8 bits for slot 'number' (for ARI devices), change slot 'number' u16 to account for special values PCI_SLOT_PLACEHOLDER and PCI_SLOT_ALL_DEVICES.

The lack of signature verification of firmware update packages in VEO and VEO-XS Wi-Fi monitors, in versions prior to 01.48.001, allows an attacker who controls the delivery of an update to install unauthorised firmware.

A JWT signature verification vulnerability affects Kong components that perform JWT validation for MCP OAuth2 or DataKit integrations inside Kong API Gateway Enterprise. The affected code does not properly validate that the JWT signing algorithm is compatible with the type of key used for verification. As a result, an unauthenticated remote attacker may be able to craft a forged JWT that is incorrectly accepted as valid, leading to authentication bypass and potential compromise of confidentiality, integrity, and availability.

In the Linux kernel, the following vulnerability has been resolved: ublk: clear VM_MAYWRITE on read-only ublk char device mmap ublk_ch_mmap() rejects mmap requests with VM_WRITE set, but never clears VM_MAYWRITE on the resulting read-only mapping. This allows a userspace daemon to mmap the per-queue command buffer PROT_READ, then upgrade it to PROT_WRITE via mprotect(), since VM_MAYWRITE was never cleared. The command buffer holds struct ublksrv_io_desc entries that are kernel-written ABI; a writable mapping lets an unprivileged daemon process corrupt fields such as addr, op_flags, nr_sectors, and start_sector. Same bug class as the drm/panthor and drm/vc4 VM_MAYWRITE fixes, and the 2026-08-13 ptp/vmclock fix (a5edadbae57e). Verified via mprotect() PoC: before the fix, a PROT_READ mapping can be upgraded to PROT_READ|PROT_WRITE and a write into the command buffer corrupts io_desc fields (confirmed under KASAN). After the fix, mprotect() returns -EACCES.

Apache Airflow Apache Kafka provider versions 1.15.0 before 2.0.0 resolve dotted-path strings found in a Kafka connection's `extra` field into Python callables via `import_string`, with no allowlist, and hand them to the confluent-kafka client which invokes them. Deployments that have enabled the Kafka event producer — `dag_run_events_enabled` or `task_instance_events_enabled`, both disabled by default — build that client inside the scheduler process, so a user whose only privilege is editing Airflow connections gains arbitrary code execution in the control plane; the Airflow security model limits connection-configuration users to code execution on workers, not the scheduler. Deployments using Google Managed Kafka are not affected, because that code path overwrites any user-supplied `oauth_cb`; plain brokers and Amazon MSK are exposed. Users are recommended to upgrade to apache-airflow-providers-apache-kafka 2.0.0 or later, which adds an allowlist configuration option for connection-string callbacks.

The lack of TLS certificate validation when downloading firmware updates in VEO and VEO-XS Wi-Fi monitors, in versions prior to 01.48.001, allows an attacker to perform man-in-the-middle attacks on the update channel.

Apache Airflow FAB provider: the Authentik OAuth path in the FAB auth manager does not validate the issuer or audience claims of the id_token it accepts. An attacker holding a token that the same Authentik identity provider minted for a different client application can present it to Airflow and be authenticated as the user it names, because the audience claim is never checked. Affects deployments using the FAB auth manager with Authentik OAuth where the same Authentik instance also serves other applications; the attacker needs a valid token for any of those other applications, not for Airflow. CVE-2026-75156 corrected the same missing validation on the Azure AD path in this file; the Authentik path was left unchanged and is fixed here. Deployments that applied the CVE-2026-75156 fix and use Authentik must also upgrade for this one. Users of apache-airflow-providers-fab are recommended to upgrade to version 3.9.0 or later, which fixes the issue.

Transmission of the home Wi-Fi credentials without encryption during the pairing process between the DuoxMe application and VEO and VEO-XS Wi-Fi monitors, in versions prior to 4.3.4 of the application and 01.50.001 of the monitor firmware, allows an attacker on the Wi-Fi Direct network to intercept the network password.

Apache Airflow FAB provider: deactivating a user account does not stop tokens issued to that account before deactivation. Password authentication correctly rejects the disabled account, but the Core API continues to accept an existing, unexpired token naming it, and lets that token mint a replacement — so the account keeps its role-scoped access indefinitely after an administrator has disabled it. The user replays their own legitimate credential; no signature forgery or privilege escalation is involved, and the access stays within the roles the account already held. Affects deployments using Airflow 3 with the FAB auth manager and Core API token authentication, where an administrator deactivates an account whose row remains in the database and whose previously issued token has not expired. The trigger is administrative deactivation as a containment action, which silently fails to contain. Users of apache-airflow-providers-fab are recommended to upgrade to version 3.9.0 or later, which rejects tokens naming a deactivated account.

The `deleteContainer` opcode (0x14/20) is processed without verifying the caller's ACL permissions, allowing any authenticated client to delete specific znodes in the data tree regardless of the ACL restrictions on the znode or its parent. This opcode is considered internal-only and the official client doesn't have API for it, but a client that can open a plain TCP session on the ZooKeeper client port (2181 by default) - with NO authentication and NO ACL permissions - can delete any empty persistent znode (including regular persistent nodes, container nodes, and TTL nodes) by issuing the raw protocol OpCode deleteContainer (20). The deleteContainer request path completely skips both the session check and the DELETE ACL check that are enforced by the regular delete (OpCode 2) path. This is an authorization bypass / ACL enforcement bug. This issue affects Apache ZooKeeper: from 3.9.0 through 3.9.5, from 3.8.0 through 3.8.6. Users are recommended to upgrade to version 3.9.6 or 3.8.7, which fixes the issue.

On affected platforms running Arista EOS with Open Shortest Path First version 3 (OSPFv3) configured, a specially crafted packet can cause the OSPFv3 agent to restart unexpectedly.

On affected platforms running Arista EOS with Open Shortest Path First version 2 (OSPFv2) configured, a specially crafted OSPFv2 packet from an unauthenticated attacker on the same broadcast segment, with OSPFv2 authentication configured can cause adjacency flapping and packet loss. The disruption can affect routing across the broader OSPF domain.

Apache ZooKeeper quorum TLS fails to enforce peer hostname verification in FIPS-mode deployments. When sslQuorum=true, zookeeper.fips-mode=true, ssl.quorum.hostnameVerification=true, and ssl.quorum.clientHostnameVerification=true are enabled, the Java SSLSocket quorum path accepts a CA-trusted peer certificate whose SAN does not match the connected host. A malicious or misissued peer certificate can therefore join quorum traffic, participate in leader election, and enter replication flows. Users are recommended to upgrade to version 3.8.7 or 3.9.6, which fixes the issue.

Information disclosure via SetWatches reconnect replay in Apache ZooKeeper due to missing ACL check. An attacker can discover ACL-restricted paths by registering exists-watches on non-existent paths, then reconnecting after the paths are created with restricted ACLs. Issue is caused by incomplete fix for CVE-2024-23944 (ZOOKEEPER-4799). The fix added ACL checking to WatchManager.triggerWatch(). However, DataTree.setWatches() — the SetWatches/SetWatches2 reconnect replay handler — still calls watcher.process(event) with null ACL, bypassing the check entirely. It's important to note that only the path is exposed by this vulnerability, not the data of znode, but since znode path can contain sensitive information like user name or login ID, this issue is potentially critical. Users are recommended to upgrade to version 3.9.6, 3.8.7 which fixes the issue.

A SAML authentication bypass vulnerability affects the Kong SAML plugin when the validate_assertion_signature option is explicitly set to false. This option is enabled by default. When disabled, the plugin may extract the SAML identity from an unsigned assertion and authenticate the user without verifying a valid cryptographic signature. As a result, an unauthenticated remote attacker may be able to submit a crafted SAML response and impersonate arbitrary users, including administrators

In the Linux kernel, the following vulnerability has been resolved: ksmbd: prevent out-of-bounds reads in share config responses Validate IPC share configuration payload sizes before consuming variable-length fields. Bound veto list parsing and account for the separator byte when deriving the path length.

In the Linux kernel, the following vulnerability has been resolved: perf: Fix use-after-free when perf mmap() revival races with the last munmap() perf_mmap_close() drops rb->mmap_count *without* holding event->mmap_mutex (the refcount_dec_and_test() right before the refcount_dec_and_mutex_lock() of event->mmap_count). A concurrent perf_mmap_rb() can slot its entire "revival" path into that window (perf_mmap holds event->mmap_mutex for its whole duration, including rb_alloc): munmap side (perf_mmap_close) mmap side (perf_mmap_rb) ----------------------------------- -------------------------------- rb->mmap_count 1 -> 0 (no lock) (holds event->mmap_mutex) inc_not_zero(rb->mmap_count) fails ring_buffer_attach(event, NULL) rb_alloc() + attach new rb refcount_set(&event->mmap_count, 1) lock; event->mmap_count 1 -> 0 ring_buffer_attach(event, NULL) ring_buffer_put() -> frees the *new* rb The revival's refcount_set(&event->mmap_count, 1) is an invisible 1 -> 1 write: the close frees the just-revived buffer although the other process still has it mapped -- a page-level use-after-free allowing local privilege escalation to root by any unprivileged user (default kernel.perf_event_paranoid=2). Swap the order of the two counter updates: event->mmap_count is dropped first via refcount_dec_and_mutex_lock(), so its 1 -> 0 transition and the ring_buffer_attach() stay serialized with perf_mmap(). rb->mmap_count == 0 then implies every event using the buffer is detached already, so the result of the rb->mmap_count drop can gate the remaining teardown directly and detach_rest is no longer needed. An earlier fix for this race from Kyle Zeng and David Lee takes event->mmap_mutex around both counter updates [0]; here the not-last close stays lockless.

In the Linux kernel, the following vulnerability has been resolved: gtp: add synchronize_net() in gtp_newlink() error path to prevent use-after-free gtp_newlink()'s error path frees tid_hash and addr_hash without waiting for an RCU grace period after clearing sk_user_data. A concurrent gtp_encap_recv() in softirq may still hold the gtp_dev pointer obtained via rcu_dereference_sk_user_data() and access the freed memory. BUG: KASAN: slab-use-after-free in gtp0_pdp_find+0x1f6/0x200 (gtp.c:152) Call Trace: <IRQ> gtp0_pdp_find+0x1f6/0x200 gtp_encap_recv+0x527/0x24b0 udp_queue_rcv_one_skb+0x75f/0xc10 Add synchronize_net() before the kfree calls in out_hashtable, which covers all error paths from both gtp_encap_enable() and gtp_create_sockets().

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: reject restart table growth beyond U16_MAX entries During $LogFile replay, log_replay() indexes the transaction table by the transact_id taken from the log record header. check_log_rec() only verifies that transact_id is non-zero and properly aligned, not its magnitude, so a crafted image can request an arbitrarily large index. alloc_rsttbl_from_idx() grows the table to cover that index via extend_rsttbl(), which passes the new entry count to init_rsttbl(): rt = init_rsttbl(esize, used + add); used + add is computed as u32 but init_rsttbl() takes a u16, and the count is stored in struct RESTART_TABLE as a __le16. When used + add exceeds U16_MAX it is truncated, init_rsttbl() allocates a table far smaller than the index requires, and alloc_rsttbl_from_idx() then dereferences and writes at the original, untruncated offset -- an out-of-bounds access past the allocation, reachable by mounting a crafted NTFS image. BUG: KASAN: use-after-free in alloc_rsttbl_from_idx (fs/ntfs3/fslog.c:950) Read of size 4 at addr ffff8880327ffff8 by task exploit alloc_rsttbl_from_idx (fs/ntfs3/fslog.c:950) log_replay (fs/ntfs3/fslog.c:4562) ntfs_loadlog_and_replay (fs/ntfs3/fsntfs.c:324) ntfs_fill_super (fs/ntfs3/super.c:1393) get_tree_bdev_flags vfs_get_tree path_mount __x64_sys_mount A restart table is limited to U16_MAX entries by its __le16 count, so a larger growth request is invalid input. Reject it in extend_rsttbl(); all callers already handle a NULL return.

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: fix out-of-bounds read in read_log_rec_buf() read_log_rec_buf() copies a log record into a caller buffer starting at u32 off = lsn_to_page_off(log, lsn) + log->record_header_len; log->record_header_len (and log->data_off, used for the following pages) comes verbatim from the on-disk restart area and is only checked for 8-byte alignment in is_rst_area_valid(), so off can exceed log->page_size. "tail = log->page_size - off" then underflows and memcpy() reads past the page_size-sized buffer returned by read_log_page(), spilling adjacent slab memory into the replay buffer. This is reachable by mounting a crafted NTFS image: BUG: KASAN: slab-out-of-bounds in read_log_rec_buf+0x216/0x580 Read of size 64 at addr ffff88800a877ff8 by task exploit/127 read_log_rec_buf fs/ntfs3/fslog.c:2299 log_replay fs/ntfs3/fslog.c:4216 ntfs_loadlog_and_replay fs/ntfs3/fsntfs.c:324 ntfs_fill_super fs/ntfs3/super.c:1392 get_tree_bdev_flags fs/super.c:1694 __x64_sys_mount fs/namespace.c:4360 The buggy address is located 4088 bytes to the right of the 4096-byte region [ffff88800a876000, ffff88800a877000) Reject an in-page offset outside the current page before the copy. [almaz.alexandrovich@paragon-software.com: replaced the >= sign with >]

In the Linux kernel, the following vulnerability has been resolved: vfio/pci: clear vdev->msi_perm after freeing it on init failure vfio_msi_cap_len() lazily allocates the per-device MSI permission table: vdev->msi_perm = kmalloc_obj(struct perm_bits, GFP_KERNEL_ACCOUNT); if (!vdev->msi_perm) return -ENOMEM; ret = init_pci_cap_msi_perm(vdev->msi_perm, len, flags); if (ret) { kfree(vdev->msi_perm); return ret; /* vdev->msi_perm left dangling */ } When init_pci_cap_msi_perm() -> alloc_perm_bits() fails with -ENOMEM, the error path frees vdev->msi_perm but leaves the freed pointer stored in it. vdev->msi_perm is not re-zeroed later because struct vfio_pci_core_device is per-device and persists across open/close cycles, and the vfio_config_init() error path returns without calling vfio_config_free(). So the dangling pointer outlives the failed open. That leads to two use-after-frees on the same device: 1. Reuse. The next vfio_config_init() sees the stale pointer at "if (vdev->msi_perm) return len;" and reuses the freed object. MSI config accesses in vfio_pci_config_rw_single() then dereference and call the freed perm->readfn / perm->writefn function pointers. 2. Double free. A later vfio_config_free() runs free_perm_bits() and kfree() on the already-freed object. Fix it by NULLing vdev->msi_perm after the kfree(), matching the NULL-after-free discipline already used in free_perm_bits() and vfio_config_free(). BUG: KASAN: slab-use-after-free in vfio_pci_config_rw_single (drivers/vfio/pci/vfio_pci_config.c:1961) Read of size 8 at addr ffff88800fcc88d0 by task exploit/143 Call Trace: ... kasan_report (mm/kasan/report.c:595) vfio_pci_config_rw_single (drivers/vfio/pci/vfio_pci_config.c:1961) vfio_pci_config_rw (drivers/vfio/pci/vfio_pci_config.c:1986) vfio_pci_rw (drivers/vfio/pci/vfio_pci_core.c:1599) vfs_read (fs/read_write.c:572) __x64_sys_pread64 (fs/read_write.c:764) do_syscall_64 (arch/x86/entry/syscall_64.c:94) ... Followed on device close by a double free of the same object: Oops: general protection fault, probably for non-canonical address 0x1f63e0e8000008: 0000 [#1] SMP KASAN NOPTI RIP: 0010:kfree (mm/slub.c:6711) Call Trace: vfio_config_free (drivers/vfio/pci/vfio_pci_config.c:1861) vfio_pci_core_disable (drivers/vfio/pci/vfio_pci_core.c:685) vfio_pci_core_close_device (drivers/vfio/pci/vfio_pci_core.c:777) vfio_df_close (drivers/vfio/vfio_main.c:602) vfio_device_fops_release (drivers/vfio/vfio_main.c:648) __fput (fs/file_table.c:512) __x64_sys_close (fs/open.c:1496) do_syscall_64 (arch/x86/entry/syscall_64.c:94) ... Kernel panic - not syncing: Fatal exception

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: SCO: hold sk properly in sco_conn_ready sk deref in sco_conn_ready must be done either under conn->lock, or holding a refcount, to avoid concurrent close. conn->sk and parent sk is currently accessed without either, and without checking parent->sk_state: [Task 1] [Task 2] sco_sock_release sco_conn_ready sk = conn->sk lock_sock(sk) conn->sk = NULL lock_sock(sk) release_sock(sk) sco_sock_kill(sk) UAF on sk deref and similarly for access to sco_get_sock_listen() return value. Fix possible UAF by holding sk refcount in sco_conn_ready() and making sco_get_sock_listen() increase refcount. Also recheck after lock_sock that the socket is still valid. Adjust conn->sk locking so it's protected also by lock_sock() of the associated socket if any.