linux vulnerabilities · Page 67

nfsd: add missing read barrier to rpc_status_get dumpit seqcount retry

In the Linux kernel, the following vulnerability has been resolved: nfsd: add missing read barrier to rpc_status_get dumpit seqcount retry The hand-rolled seqcount-like protocol in nfsd_nl_rpc_status_get_dumpit() is missing a read memory barrier (smp_rmb) before its second counter check. The standard kernel read_seqcount_retry() includes smp_rmb() to ensure that all data reads complete before the counter is re-checked. Without this barrier, on weakly-ordered architectures (ARM, POWER), the CPU may reorder field reads past the second counter check, making the retry logic ineffective: it could observe a consistent counter pair while reading

• Update to 6.12.111-1

svcrdma: Reject Write/Reply chunks with segcount 0

In the Linux kernel, the following vulnerability has been resolved: svcrdma: Reject Write/Reply chunks with segcount 0 A peer can send a Write or Reply chunk whose segcount field is zero. xdr_check_write_chunk() only rejects segcount > rc_maxpages, so zero passes the range check, and xdr_inline_decode(stream, 0) returns the current (non-NULL) cursor without advancing. The function returns true and pcl_alloc_write() then links a struct svc_rdma_chunk with ch_segcount == 0 onto rc_write_pcl or rc_reply_pcl. An earlier patch in this series made pcl_for_each_segment() safe for ch_segcount == 0, so this no longer drives the memory walk it used

• Update to 6.12.111-1

ipv6: use RCU iterator to dump route exceptions

In the Linux kernel, the following vulnerability has been resolved: ipv6: use RCU iterator to dump route exceptions rt6_nh_dump_exceptions() uses hlist_for_each_entry() to iterate over RCU-protected exception lists. The caller holds rcu_read_lock(), but does not hold rt6_exception_lock, so rt6_insert_exception() can concurrently add an entry with hlist_add_head_rcu(). KCSAN reports this race (irrelevant details omitted): ================================================================== BUG: KCSAN: data-race in rt6_insert_exception / rt6_nh_dump_exceptions write (marked) to 0xffff8a7c44c59620 of 8 bytes by interrupt on cpu 5: r

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svcrdma: Fix unmatched rn_unregister on failed accept

In the Linux kernel, the following vulnerability has been resolved: svcrdma: Fix unmatched rn_unregister on failed accept When svc_rdma_accept() takes the errout path before rpcrdma_rn_register() has succeeded, the existing cleanup block calls rpcrdma_rn_unregister(dev, &newxprt->sc_rn) unconditionally. svcxprt_rdma is kzalloc'd, so on that path sc_rn.rn_index is 0 and sc_rn.rn_done is NULL; the unregister therefore xa_erase()s another caller's slot 0 and performs an unmatched kref_put() on the rpcrdma_device's rd_kref. The same errout also brackets the cleanup with svc_xprt_get()/ svc_xprt_put() around the kref_init() birth reference. The

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staging: media: tegra-video: fix of_node_put() on VIP parse errors

In the Linux kernel, the following vulnerability has been resolved: staging: media: tegra-video: fix of_node_put() on VIP parse errors tegra_vip_channel_of_parse() initializes np from dev->of_node without taking a reference, but its error paths drop one through the err_node_put label. This underflows the refcount of the VIP device's OF node when endpoint parsing fails on a malformed device tree. The only reference the function takes on np is the success-path of_node_get() stored in vip->chan.of_node, and that one is already released by the tegra_vip_init() error path and by tegra_vip_exit(). Return errors directly instead of jumping to th

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signal: avoid shared siginfo namespace rewrites

In the Linux kernel, the following vulnerability has been resolved: signal: avoid shared siginfo namespace rewrites send_signal_locked() rewrites sender ids for the target namespace. Group sends reuse the same siginfo, so one recipient can affect the next. Copy the siginfo before changing it.

• Update to 6.12.111-1

nfsd: convert nfsd_net boolean flags to unsigned long flags word

In the Linux kernel, the following vulnerability has been resolved: nfsd: convert nfsd_net boolean flags to unsigned long flags word nfsd_net contains several boolean fields that are accessed from concurrent contexts without serialization. In particular, nfsd4_end_grace() guards its drain path with a plain bool: if (nn->grace_ended) return; nn->grace_ended = true; The read and the write are independent, and nothing in struct nfsd_net serializes them. At least two contexts can reach this code with no lock held: laundromat path laundry_wq kworker nfs4_laundromat() nfsd4_end_grace() REC

clocksource/drivers/timer-sun4i: Advertise a real minimum delta

In the Linux kernel, the following vulnerability has been resolved: clocksource/drivers/timer-sun4i: Advertise a real minimum delta sun4i_clkevt_next_event() compensates for the timer stop/start synchronization delay by programming evt - TIMER_SYNC_TICKS into the hardware interval register. The clockevent device currently advertises TIMER_SYNC_TICKS as min_delta_ticks, so the clockevents core is allowed to call set_next_event() with evt == TIMER_SYNC_TICKS. That programs a zero-tick interval. With oneshot/highres/nohz timer operation this can leave the next event stuck, which was observed as a boot hang on Allwinner D1 after the clockevent

• Update to 6.12.111-1

mm/page_owner: use memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg()

In the Linux kernel, the following vulnerability has been resolved: mm/page_owner: use memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg() print_page_owner_memcg() reads page->memcg_data via READ_ONCE() at the start to guard against tail pages and NULL data. However, it later re-reads page->memcg_data locklessly in two places: 1: page_memcg_check(page) 2: PageMemcgKmem(page) (via folio_memcg_kmem(), which includes VM_BUG_ON assertions for tail pages and MEMCG_DATA_OBJEXTS) If the page is concurrently freed and reallocated as a THP tail page or slab page between these calls, the VM_BUG_ON assertions can trigger on CONFIG_D

cdx: Fix double free when sysfs file creation fails

In the Linux kernel, the following vulnerability has been resolved: cdx: Fix double free when sysfs file creation fails In cdx_create_res_attr(), if sysfs_create_bin_file() fails, the code frees res_attr but doesn't set cdx_dev->res_attr[num] to NULL. This leaves a dangling pointer in the array. Then cdx_destroy_res_attr() frees the already-freed memory. Fix the double free by initializing cdx_dev->res_attr[num] after sysfs_create_bin_file() completes.

• Update to 6.12.111-1

usb: gadget: f_tcm: fix deadlock in usbg_make_tpg()

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_tcm: fix deadlock in usbg_make_tpg() usbg_make_tpg() held dep_lock while calling configfs_depend_item_unlocked(), which acquires the configfs root inode lock when operating across subsystems. This creates a circular lock dependency with configfs_rmdir(): dep_lock -> configfs root inode lock -> su_mutex -> dep_lock In usbg_make_tpg(), dep_lock only serialized the read of opts->ready, which is a monotonic flag that transitions from false to true exactly once (in tcm_set_name()) and never reverts. Remove dep_lock from usbg_make_tpg() entirely and use READ_ON

• Update to 6.12.111-1

of: fix out-of-bounds read in of_alias_scan() stem parser

In the Linux kernel, the following vulnerability has been resolved: of: fix out-of-bounds read in of_alias_scan() stem parser The stem parser tests isdigit(*(end - 1)) before checking end > start and so reads one byte before the property name when the name is empty or all digits. Check the bound first.

• Update to 6.12.111-1

nfsd: guard nfsd_serv deref in nfsd_file_net_dispose

In the Linux kernel, the following vulnerability has been resolved: nfsd: guard nfsd_serv deref in nfsd_file_net_dispose nfsd_file_net_dispose() is the consumer side of l->freeme: the nfsd service thread loop calls it to drain entries that the filecache garbage collector and shrinker append via nfsd_file_dispose_list_delayed(). During per-net teardown, nn->nfsd_serv is cleared before the filecache laundrette is shut down, so the service thread can still run a dispose pass that finds more than eight entries on l->freeme and dereferences a NULL svc_serv: nfsd service thread loop nfsd_file_net_dispose(nn) if (!list_empty(&l

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nfsd: initialize DRC hash table before registering shrinker

In the Linux kernel, the following vulnerability has been resolved: nfsd: initialize DRC hash table before registering shrinker shrinker_register() precedes the INIT_LIST_HEAD loop and the drc_hashsize store. On weakly-ordered architectures (arm64, ppc), a shrinker scan can observe drc_hashsize before the bucket list heads are initialized, causing a NULL deref in the DRC shrinker callback. Move bucket initialization and the drc_hashsize store before shrinker_register() so the hash table is fully initialized before it becomes visible to the shrinker.

• Update to 6.12.111-1

smb: client: harden DFS cache against invalid target hints

In the Linux kernel, the following vulnerability has been resolved: smb: client: harden DFS cache against invalid target hints Currently, get_tgt_name() returns ERR_PTR(-ENOENT) when ce->tgthint is NULL, and dfs_cache_noreq_update_tgthint() assumes ce->tgthint is always valid. In preparation for clearing ce->tgthint in free_tgts(), harden callers of get_tgt_name() against ERR_PTR results and harden dfs_cache_noreq_update_tgthint() against NULL pointer dereferences.

• Update to 6.12.111-1

Bluetooth: hci_core: use skb_get() instead of skb_clone() for req_skb

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: use skb_get() instead of skb_clone() for req_skb BT enable fails intermittently with -ETIMEDOUT (-110). The kernel log shows the HCI Read Local Version command was sent and the firmware replied with status 0x00 (logged by hci_req_cmd_complete() BT_DBG), but the waiter in __hci_cmd_sync_sk() never woke up and timed out after 10 s: bluetooth hci0: Opcode 0xfc00 // __hci_cmd_sync_sk bluetooth hci0: opcode 0xfc00 plen 1 // hci_cmd_sync_add bluetooth hci0: skb len 4 // hci_cmd_sync_alloc bluetooth hci0: length 1

• Update to 6.12.111-1

kasan: fix cache shrink race with CPU hotplug

In the Linux kernel, the following vulnerability has been resolved: kasan: fix cache shrink race with CPU hotplug kasan_quarantine_remove_cache() first invokes per_cpu_remove_cache() on all online CPUs. Each callback moves objects belonging to the cache from cpu_quarantine to the CPU's shrink_qlist, where they can later be freed from task context. kmem_cache_destroy() invokes the quarantine removal path while holding cpus_read_lock(), but kmem_cache_shrink() does not. The latter can therefore race with CPU offlining as follows: kmem_cache_shrink() CPU hotplug ------------------- ----------- on_each_cpu()

• Update to 6.12.111-1

SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry svcauth_gss_decode_credbody() writes the caller's rpc_gss_wire_cred field by field and assigns gc_ctx.len only on the success tail. The caller storage is svcdata->clcred, which lives in the per-svc_rqst gss_svc_data and is reused across requests. Early decode failures leave partially decoded state mixed with residue from the prior request. The trailing body_len tightness check is the sharpest case: xdr_stream_decode_opaque_inline() has already written gc_ctx.data with a borrowed inline pointer into the

• Update to 6.12.111-1

PCI/proc: Use file_ns_capable() when checking config space read access

In the Linux kernel, the following vulnerability has been resolved: PCI/proc: Use file_ns_capable() when checking config space read access proc_bus_pci_read() decides how much of the config space is readable based on capable(CAP_SYS_ADMIN), which checks the credentials of the task calling read(), not the credentials of the process that opened the file. The sysfs equivalent, pci_read_config(), has checked the credentials of the opening process since commit de139a339395 ("pci: check caps from sysfs file open to read device dependent config space"), so a privileged process can open the config space file and pass the file descriptor to an unpr

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iommu/arm-smmu-v3: Manage teardown with devm

In the Linux kernel, the following vulnerability has been resolved: iommu/arm-smmu-v3: Manage teardown with devm arm_smmu_device_remove() manually frees the IOPF queue, destroys the vmid_map and disables the device, while the IRQs and queues are devm managed. devm unwinds only after remove() returns, so the cleanup runs in the wrong order. The IOPF queue is freed before the event-queue IRQ whose handler uses it. Manage all of it with devm so the unwind order is correct. Free the IOPF queue and vmid_map via devm actions, and disable the device from one registered after arm_smmu_device_reset(). This is also a prerequisite for fixing a Tegra

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