Vulnerabilidades

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> tls: rx: restore msg_iter before TLS 1.3 optimistic retry<br /> <br /> tls_decrypt_sg() advances msg-&gt;msg_iter when it maps user pages for<br /> the optimistic TLS 1.3 zero-copy path. If the decrypted record turns<br /> out not to be unpadded application data, tls_decrypt_sw() retries into<br /> a kernel skb, but leaves the iterator advanced.<br /> <br /> The subsequent copy from the skb then writes decrypted bytes again at<br /> a later point in the caller iovecs while recvmsg() reports only the<br /> post-retry length. A TLS peer can trigger this after the receiver<br /> enables TLS_RX_EXPECT_NO_PAD.<br /> <br /> Revert the iterator by the number of bytes consumed by the optimistic<br /> mapping before retrying without zero-copy.<br /> <br /> Add a selftest which sends a TLS 1.3 control record with<br /> TLS_RX_EXPECT_NO_PAD enabled and verifies that recvmsg() does not<br /> overwrite later iovecs beyond the returned length.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> veth: fix skb length accounting after XDP frag adjustment<br /> <br /> veth exposes non-linear skb fragments through an xdp_buff. If an XDP<br /> program adjusts the fragment area, veth_xdp_rcv_skb() copies<br /> xdp_frags_size back to skb-&gt;data_len but leaves skb-&gt;len containing the<br /> old fragment contribution.<br /> <br /> After a fragment shrink, this makes skb_headlen() larger than the actual<br /> linear area. In the reproduced UDP receive path, __skb_datagram_iter()<br /> copied 1024 bytes past the actual linear tail to userspace, starting at<br /> struct skb_shared_info. The copied bytes included the affected skb&amp;#39;s<br /> nr_frags, xdp_frags_size, and a kernel pointer from<br /> skb_shinfo(skb)-&gt;frags[0]. Real packet data was displaced by the same<br /> amount and truncated at the end.<br /> <br /> Subtract the old data_len before replacing it and add the new data_len<br /> afterwards, keeping skb-&gt;len and skb-&gt;data_len synchronized.<br /> <br /> Additionally, bpf_xdp_pull_data() can advance data_end while leaving<br /> frags present. The skb is then still non-linear, so the old<br /> __skb_put(skb, off) triggers SKB_LINEAR_ASSERT().<br /> <br /> Use skb_set_tail_pointer() and update skb-&gt;len explicitly instead,<br /> following bpf_prog_run_generic_xdp(). Unlike __skb_put(),<br /> skb_set_tail_pointer() does not require a linear skb.<br /> <br /> A 60000-byte UDP datagram on a veth pair with MTU 64000 was shortened by<br /> 1024 bytes from its fragment area. Before the fix, all 10 runs produced<br /> corrupted payloads. After the fix, all 10 runs matched the expected<br /> payload exactly. A forced-tailroom reproducer also exercises<br /> bpf_xdp_pull_data() with frags still present; the old code triggers<br /> SKB_LINEAR_ASSERT(), while this fix passes 10/10 runs.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> vsock/virtio: avoid refilling the RX queue after teardown<br /> <br /> Commit b917507e5ad9 ("vsock/virtio: stop workers during the .remove()")<br /> made the RX worker jump to its common exit when rx_run is clear. That<br /> exit still refills the RX queue when the buffer count is low, so work<br /> queued across virtio_vsock_vqs_del() can add buffers after the virtqueues<br /> have been deleted.<br /> <br /> BUG: KASAN: slab-use-after-free in virtqueue_add_sgs<br /> Read of size 4 by task kworker/0:1<br /> Workqueue: virtio_vsock virtio_transport_rx_work<br /> Call Trace:<br /> virtqueue_add_sgs (drivers/virtio/virtio_ring.c:2796)<br /> virtio_vsock_rx_fill (net/vmw_vsock/virtio_transport.c:332)<br /> virtio_transport_rx_work (net/vmw_vsock/virtio_transport.c:701)<br /> process_one_work (kernel/workqueue.c:3314)<br /> worker_thread (kernel/workqueue.c:3478)<br /> kthread (kernel/kthread.c:436)<br /> ret_from_fork (arch/x86/kernel/process.c:158)<br /> ret_from_fork_asm (arch/x86/entry/entry_64.S:245)<br /> ...<br /> Freed by task 141:<br /> kfree (mm/slub.c:6566)<br /> vp_del_vq (drivers/virtio/virtio_pci_common.c:259)<br /> vp_del_vqs (drivers/virtio/virtio_pci_common.c:285)<br /> virtio_vsock_freeze (net/vmw_vsock/virtio_transport.c:912)<br /> virtio_device_freeze (drivers/virtio/virtio.c:658)<br /> virtio_pci_freeze (drivers/virtio/virtio_pci_common.c:601)<br /> pci_pm_freeze (drivers/pci/pci-driver.c:1098)<br /> device_suspend (drivers/base/power/main.c:1968)<br /> Kernel panic - not syncing: KASAN: panic_on_warn set ...<br /> <br /> Jump to a no-refill exit when rx_run is clear, leaving the normal exit<br /> to replenish a running queue.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ip6_tunnel: clear skb2-&gt;cb[] in ip6ip6_err()<br /> <br /> ip6ip6_err() clones an outer IPv6 ICMP error skb, pulls it to the<br /> quoted inner IPv6 packet, and then passes the clone to icmpv6_send().<br /> The clone still carries the outer packet&amp;#39;s inet6_skb_parm in skb-&gt;cb.<br /> <br /> If the outer packet had a Home Address Option, IP6CB(skb2)-&gt;dsthao<br /> remains non-zero after skb_pull(). icmpv6_send() later calls<br /> mip6_addr_swap(), which uses that stale dsthao offset against the quoted<br /> inner packet. A malformed inner destination-options header can then make<br /> the HAO lookup and address swap run past the end of the quoted packet<br /> and corrupt skb_shared_info.<br /> <br /> Clear skb2-&gt;cb[] before pulling the quoted inner IPv6 packet so the<br /> reply path does not reuse metadata left by the outer IPv6 stack.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ipv6: fix Route Information option length validation<br /> <br /> rt6_route_rcv() validates the Route Information option (RFC 4191) length<br /> against the prefix length, but both checks are off by one.<br /> <br /> rinfo-&gt;length is the ND option length in units of 8 octets and it<br /> *includes* the 8-byte option header, so an option carrying N bytes of<br /> prefix has length == 1 + N/8. RFC 4191 section 2.3 requires length 3<br /> when Prefix Length is greater than 64, and 2 or 3 when it is greater<br /> than 0. The code accepts length &gt;= 2 and length &gt;= 1 respectively.<br /> <br /> ipv6_addr_prefix() then copies prefix_len/8 bytes out of rinfo-&gt;prefix,<br /> so a Router Advertisement with (prefix_len=128, length=2) or<br /> (prefix_len=64, length=1) makes the kernel read up to 8 bytes past the<br /> end of the option. Those bytes end up in the prefix of the route that<br /> gets installed, so they are visible to userspace:<br /> <br /> # RA with a Route Information option (prefix_len=128, length=2)<br /> # followed by a source link-layer address option, 01 01 de ad be ef ca fe<br /> $ ip -6 route show<br /> 2001:db8:dead:beef:101:dead:beef:cafe via fe80::1234 dev veth0 proto ra<br /> ^^^^^^^^^^^^^^^^^^ the next option, read out of bounds<br /> <br /> When the Route Information option is the last one in the packet, those<br /> eight bytes come from the skb tail room instead.<br /> <br /> Reject the option lengths RFC 4191 does not allow.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mm/ptdump: always stabilise against page table freeing using init_mm<br /> <br /> Previous commits have established the invariant that kernel page table<br /> freeing is performed while an mmap read lock on init_mm is held, which<br /> fixes races between ptdump and kernel page table freeing over init_mm.<br /> <br /> However, x86 and arm64 can perform a ptdump over an mm other than init_mm<br /> via ptdump_walk_pgd() and since kernel memory ranges are shared across<br /> non-kernel mm&amp;#39;s, this means that the race still exists for these cases.<br /> <br /> Fix this by acquiring a nested mmap write lock for init_mm in<br /> ptdump_walk_pgd().<br /> <br /> This is safe as we take this after mmap write locking the mm, and nothing<br /> acquires the init_mm lock first before locking an arbitrary mm, so no<br /> deadlock is possible.<br /> <br /> Also update walk_page_range_debug() to assert that init_mm is write<br /> locked, add a comment explaining why and remove some redundant code, and<br /> eliminate the unnecessary and confusing invocation of<br /> walk_kernel_page_table_range().<br /> <br /> We can safely remove the non-NULL check for walk.mm, as the mmap lock<br /> asserts would NULL pointer deref if it was (and of course no callers do<br /> this).<br /> <br /> The first point at which ptdump can race kernel page table freeing is<br /> commit b6bdb7517c3d ("mm/vmalloc: add interfaces to free unmapped page<br /> table"), so we target this in the Fixes tag.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mm/page_table_check: skip special zero mappings<br /> <br /> page_table_check_set() and page_table_check_clear() account mappings based<br /> on PageAnon(). Shared zero-page PTEs and huge zero PMDs are special<br /> mappings, but page_table_check can still account them as file-backed<br /> pages.<br /> <br /> An unprivileged process can populate enough zero mappings to overflow<br /> file_map_count and hit the existing BUG_ON(). The PTE path can do this<br /> with the shared zero page, and the PMD path can do the same with huge zero<br /> mappings.<br /> <br /> Skip special zero mappings in the user page-table accounting paths. Keep<br /> the PTE-side pte_special() check, and identify huge zero PMDs from the<br /> mapped folio instead of pmd_special(). That covers architectures where<br /> pmd_special() is a no-op without adding huge_zero_pfn checks to the<br /> generic counter helpers.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ring-buffer: Use current_context for safe per-CPU buffer swap<br /> <br /> The ring_buffer_swap_cpu() function currently checks the per-CPU<br /> committing counter to determine if a buffer is actively being written to<br /> before performing the swap. However, there exists a race window where<br /> this check can be bypassed:<br /> <br /> ring_buffer_lock_reserve<br /> cpu_buffer = buffer-&gt;buffers[cpu]; // cpu_buffer_a<br /> rb_reserve_next_event<br /> rb_start_commit // inc committing<br /> if (unlikely(READ_ONCE(cpu_buffer-&gt;buffer) != buffer)) {...}<br /> __rb_reserve_next<br /> rb_move_tail<br /> rb_end_commit(cpu_buffer); // dec committing =&gt; 0<br /> /* interrupt hits here, successfully swaps! */<br /> local_inc(&amp;cpu_buffer-&gt;committing);<br /> <br /> ring_buffer_unlock_commit<br /> cpu_buffer = buffer-&gt;buffers[cpu]; // cpu_buffer_b<br /> rb_commit<br /> rb_end_commit<br /> RB_WARN_ON(cpu_buffer, !local_read(&amp;cpu_buffer-&gt;committing))<br /> // triggers warning<br /> <br /> The committing counter can temporarily drop to 0 during a single write<br /> operation (within rb_move_tail), creating a window where swap can<br /> succeed even though the write is still in progress. This leads to<br /> inconsistent buffer state and triggers the RB_WARN_ON in rb_commit().<br /> <br /> Replace the committing counter check with current_context checks, which<br /> are set at the entry of ring_buffer_lock_reserve() and remain valid<br /> throughout the entire write operation, providing a reliable indicator of<br /> buffer busy state during swap.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ring-buffer: Initialise reader page order in rb_allocate_cpu_buffer()<br /> <br /> In rb_allocate_cpu_buffer(), bpage-&gt;order was omitted, leaving it as 0.<br /> This is an issue for a ring-buffer with subbufs bigger than PAGE_SIZE if<br /> when freed: free_buffer_page() relies on this value. Align the value<br /> with the actual allocation size (buffer::subbuf_order).

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ptp: ocp: Fix board ID over-read<br /> <br /> The EEPROM board ID is a fixed 13-byte field and is not guaranteed to<br /> contain a NUL terminator. Passing it directly to<br /> devlink_info_version_fixed_put() treats it as a C string and may read<br /> beyond the field.<br /> <br /> Format at most OCP_BOARD_ID_LEN bytes into the existing local buffer<br /> before reporting the ID. Use a precision limit because the snprintf()<br /> output size alone does not bound the source string scan.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> Revert "thermal/drivers/hwmon: Cleanup coding style a bit"<br /> <br /> Revert commit 030a48b0f6ce ("thermal/drivers/hwmon: Cleanup coding style<br /> a bit") that introduced a use-after-free into the error path of<br /> thermal_add_hwmon_sysfs() by removing a valid check from it.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> eventfs: Use children field for rcu head and add memory barriers<br /> <br /> When an eventfs inode is freed, it sets ei-&gt;is_freed and then uses its<br /> ei-&gt;list to add it to the srcu link list as the list field is a union with<br /> the rcu list head. As the ei-&gt;list is used to iterate over an SRCU<br /> protected list without taking the eventfs_mutex, there&amp;#39;s nothing stopping<br /> the iteration over that list to see the ei-&gt;rcu instead of the ei-&gt;list<br /> and it will read a corrupt target.<br /> <br /> To fix this, change the union of the rcu list head with the children list.<br /> On freeing the eventfs inode, set the is_free and execute a smp_wmb()<br /> before adding the eventfs inode to the SRCU list.<br /> <br /> On iteration of the ei-&gt;children list, at the start, execute a smp_rmb()<br /> and then read the is_freed of the ei to see if the children list is still<br /> valid. If is_freed is set, then the ei_child read is not valid and the<br /> loop should exit immediately.