CVSS: -EPSS: 0%CPEs: 7EXPL: 0CVE-2024-26687 – xen/events: close evtchn after mapping cleanup
https://notcve.org/view.php?id=CVE-2024-26687
In the Linux kernel, the following vulnerability has been resolved: xen/events: close evtchn after mapping cleanup shutdown_pirq and startup_pirq are not taking the irq_mapping_update_lock because they can't due to lock inversion. Both are called with the irq_desc->lock being taking. The lock order, however, is first irq_mapping_update_lock and then irq_desc->lock. This opens multiple races: - shutdown_pirq can be interrupted by a function that allocates an event channel: CPU0 CPU1 shutdown_pirq { xen_evtchn_close(e) __startup_pirq { EVTCHNOP_bind_pirq -> returns just freed evtchn e set_evtchn_to_irq(e, irq) } xen_irq_info_cleanup() { set_evtchn_to_irq(e, -1) } } Assume here event channel e refers here to the same event channel number. After this race the evtchn_to_irq mapping for e is invalid (-1). - __startup_pirq races with __unbind_from_irq in a similar way. Because __startup_pirq doesn't take irq_mapping_update_lock it can grab the evtchn that __unbind_from_irq is currently freeing and cleaning up. In this case even though the event channel is allocated, its mapping can be unset in evtchn_to_irq. The fix is to first cleanup the mappings and then close the event channel. • https://git.kernel.org/stable/c/d46a78b05c0e37f76ddf4a7a67bf0b6c68bada55 https://git.kernel.org/stable/c/9470f5b2503cae994098dea9682aee15b313fa44 https://git.kernel.org/stable/c/0fc88aeb2e32b76db3fe6a624b8333dbe621b8fd https://git.kernel.org/stable/c/ea592baf9e41779fe9a0424c03dd2f324feca3b3 https://git.kernel.org/stable/c/585a344af6bcac222608a158fc2830ff02712af5 https://git.kernel.org/stable/c/20980195ec8d2e41653800c45c8c367fa1b1f2b4 https://git.kernel.org/stable/c/9be71aa12afa91dfe457b3fb4a444c42b1ee036b https://git.kernel.org/stable/c/fa765c4b4aed2d64266b694520ecb025c •
CVSS: 5.5EPSS: 0%CPEs: 3EXPL: 0CVE-2024-26686 – fs/proc: do_task_stat: use sig->stats_lock to gather the threads/children stats
https://notcve.org/view.php?id=CVE-2024-26686
In the Linux kernel, the following vulnerability has been resolved: fs/proc: do_task_stat: use sig->stats_lock to gather the threads/children stats lock_task_sighand() can trigger a hard lockup. If NR_CPUS threads call do_task_stat() at the same time and the process has NR_THREADS, it will spin with irqs disabled O(NR_CPUS * NR_THREADS) time. Change do_task_stat() to use sig->stats_lock to gather the statistics outside of ->siglock protected section, in the likely case this code will run lockless. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: fs/proc: do_task_stat: use sig->stats_lock para recopilar las estadísticas de subprocesos/hijos lock_task_sighand() puede desencadenar un bloqueo completo. Si los subprocesos NR_CPUS llaman a do_task_stat() al mismo tiempo y el proceso tiene NR_THREADS, girará con irqs deshabilitados O(NR_CPUS * NR_THREADS) tiempo. Cambie do_task_stat() para usar sig->stats_lock para recopilar las estadísticas fuera de ->sección protegida siglock, en el caso probable de que este código se ejecute sin bloqueo. • https://git.kernel.org/stable/c/cf4b8c39b9a0bd81c47afc7ef62914a62dd5ec4d https://git.kernel.org/stable/c/27978243f165b44e342f28f449b91327944ea071 https://git.kernel.org/stable/c/7601df8031fd67310af891897ef6cc0df4209305 https://access.redhat.com/security/cve/CVE-2024-26686 https://bugzilla.redhat.com/show_bug.cgi?id=2273109 • CWE-413: Improper Resource Locking •
CVSS: 5.5EPSS: 0%CPEs: 12EXPL: 0CVE-2024-26685 – nilfs2: fix potential bug in end_buffer_async_write
https://notcve.org/view.php?id=CVE-2024-26685
In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix potential bug in end_buffer_async_write According to a syzbot report, end_buffer_async_write(), which handles the completion of block device writes, may detect abnormal condition of the buffer async_write flag and cause a BUG_ON failure when using nilfs2. Nilfs2 itself does not use end_buffer_async_write(). But, the async_write flag is now used as a marker by commit 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") as a means of resolving double list insertion of dirty blocks in nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the resulting crash. This modification is safe as long as it is used for file data and b-tree node blocks where the page caches are independent. However, it was irrelevant and redundant to also introduce async_write for segment summary and super root blocks that share buffers with the backing device. This led to the possibility that the BUG_ON check in end_buffer_async_write would fail as described above, if independent writebacks of the backing device occurred in parallel. The use of async_write for segment summary buffers has already been removed in a previous change. Fix this issue by removing the manipulation of the async_write flag for the remaining super root block buffer. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: nilfs2: corrige un posible error en end_buffer_async_write Según un informe de syzbot, end_buffer_async_write(), que maneja la finalización de las escrituras del dispositivo de bloque, puede detectar una condición anormal del indicador async_write del búfer y causar un Error BUG_ON al usar nilfs2. • https://git.kernel.org/stable/c/7f42ec3941560f0902fe3671e36f2c20ffd3af0a https://git.kernel.org/stable/c/ccebcc74c81d8399c7b204aea47c1f33b09c2b17 https://git.kernel.org/stable/c/831c87640d23ccb253a02e4901bd9a325b5e8c2d https://git.kernel.org/stable/c/d8974c7fe717ee8fb0706e35cc92e0bcdf660ec5 https://git.kernel.org/stable/c/8f67918af09fc0ffd426a9b6f87697976d3fbc7b https://git.kernel.org/stable/c/c4a09fdac625e64abe478dcf88bfa20406616928 https://git.kernel.org/stable/c/d31c8721e816eff5ca6573cc487754f357c093cd https://git.kernel.org/stable/c/f3e4963566f58726d3265a727116a42b5 •
CVSS: 4.7EPSS: 0%CPEs: 4EXPL: 0CVE-2023-52639 – KVM: s390: vsie: fix race during shadow creation
https://notcve.org/view.php?id=CVE-2023-52639
In the Linux kernel, the following vulnerability has been resolved: KVM: s390: vsie: fix race during shadow creation Right now it is possible to see gmap->private being zero in kvm_s390_vsie_gmap_notifier resulting in a crash. This is due to the fact that we add gmap->private == kvm after creation: static int acquire_gmap_shadow(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) { [...] gmap = gmap_shadow(vcpu->arch.gmap, asce, edat); if (IS_ERR(gmap)) return PTR_ERR(gmap); gmap->private = vcpu->kvm; Let children inherit the private field of the parent. En el kernel de Linux, se resolvió la siguiente vulnerabilidad: KVM: s390: vsie: corrige la ejecución durante la creación de la sombra. En este momento es posible ver que gmap->private es cero en kvm_s390_vsie_gmap_notifier, lo que provoca un bloqueo. Esto se debe al hecho de que agregamos gmap->private == kvm después de la creación: static int adquirir_gmap_shadow(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) { [...] gmap = gmap_shadow(vcpu->arch.gmap, asce, edat); si (IS_ERR(gmap)) devuelve PTR_ERR(gmap); gmap->privado = vcpu->kvm; Deje que los niños hereden el campo privado del padre. • https://git.kernel.org/stable/c/a3508fbe9dc6dd3bece0c7bf889cc085a011738c https://git.kernel.org/stable/c/5df3b81a567eb565029563f26f374ae3803a1dfc https://git.kernel.org/stable/c/f5572c0323cf8b4f1f0618178648a25b8fb8a380 https://git.kernel.org/stable/c/28bb27824f25f36e5f80229a358d66ee09244082 https://git.kernel.org/stable/c/fe752331d4b361d43cfd0b89534b4b2176057c32 https://access.redhat.com/security/cve/CVE-2023-52639 https://bugzilla.redhat.com/show_bug.cgi?id=2273080 • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') •
CVSS: 5.5EPSS: 0%CPEs: 5EXPL: 0CVE-2023-52638 – can: j1939: prevent deadlock by changing j1939_socks_lock to rwlock
https://notcve.org/view.php?id=CVE-2023-52638
In the Linux kernel, the following vulnerability has been resolved: can: j1939: prevent deadlock by changing j1939_socks_lock to rwlock The following 3 locks would race against each other, causing the deadlock situation in the Syzbot bug report: - j1939_socks_lock - active_session_list_lock - sk_session_queue_lock A reasonable fix is to change j1939_socks_lock to an rwlock, since in the rare situations where a write lock is required for the linked list that j1939_socks_lock is protecting, the code does not attempt to acquire any more locks. This would break the circular lock dependency, where, for example, the current thread already locks j1939_socks_lock and attempts to acquire sk_session_queue_lock, and at the same time, another thread attempts to acquire j1939_socks_lock while holding sk_session_queue_lock. NOTE: This patch along does not fix the unregister_netdevice bug reported by Syzbot; instead, it solves a deadlock situation to prepare for one or more further patches to actually fix the Syzbot bug, which appears to be a reference counting problem within the j1939 codebase. [mkl: remove unrelated newline change] En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: can: j1939: previene el interbloqueo cambiando j1939_socks_lock a rwlock Los siguientes 3 bloqueos competirían entre sí, causando la situación de interbloqueo en el informe de error de Syzbot: - j1939_socks_lock - active_session_list_lock - sk_session_queue_lock A Una solución razonable es cambiar j1939_socks_lock por un rwlock, ya que en las raras situaciones en las que se requiere un bloqueo de escritura para la lista vinculada que j1939_socks_lock está protegiendo, el código no intenta adquirir más bloqueos. Esto rompería la dependencia del bloqueo circular, donde, por ejemplo, el subproceso actual ya bloquea j1939_socks_lock e intenta adquirir sk_session_queue_lock y, al mismo tiempo, otro subproceso intenta adquirir j1939_socks_lock mientras mantiene sk_session_queue_lock. NOTA: Este parche no soluciona el error unregister_netdevice informado por Syzbot; en cambio, resuelve una situación de punto muerto para prepararse para uno o más parches adicionales para corregir el error Syzbot, que parece ser un problema de conteo de referencias dentro del código base j1939. [mkl: eliminar cambio de nueva línea no relacionado] A vulnerability was found in the Linux kernel's Controller Area Network (CAN) protocol, within the J1939 protocol implementation. • https://git.kernel.org/stable/c/03358aba991668d3bb2c65b3c82aa32c36851170 https://git.kernel.org/stable/c/aedda066d717a0b4335d7e0a00b2e3a61e40afcf https://git.kernel.org/stable/c/26dfe112ec2e95fe0099681f6aec33da13c2dd8e https://git.kernel.org/stable/c/559b6322f9480bff68cfa98d108991e945a4f284 https://git.kernel.org/stable/c/6cdedc18ba7b9dacc36466e27e3267d201948c8d https://access.redhat.com/security/cve/CVE-2023-52638 https://bugzilla.redhat.com/show_bug.cgi?id=2273082 • CWE-833: Deadlock •