CVSS: -EPSS: 0%CPEs: 7EXPL: 0CVE-2024-26688 – fs,hugetlb: fix NULL pointer dereference in hugetlbs_fill_super
https://notcve.org/view.php?id=CVE-2024-26688
In the Linux kernel, the following vulnerability has been resolved: fs,hugetlb: fix NULL pointer dereference in hugetlbs_fill_super When configuring a hugetlb filesystem via the fsconfig() syscall, there is a possible NULL dereference in hugetlbfs_fill_super() caused by assigning NULL to ctx->hstate in hugetlbfs_parse_param() when the requested pagesize is non valid. E.g: Taking the following steps: fd = fsopen("hugetlbfs", FSOPEN_CLOEXEC); fsconfig(fd, FSCONFIG_SET_STRING, "pagesize", "1024", 0); fsconfig(fd, FSCONFIG_CMD_CREATE, NULL, NULL, 0); Given that the requested "pagesize" is invalid, ctxt->hstate will be replaced with NULL, losing its previous value, and we will print an error: ... ... case Opt_pagesize: ps = memparse(param->string, &rest); ctx->hstate = h; if (!ctx->hstate) { pr_err("Unsupported page size %lu MB\n", ps / SZ_1M); return -EINVAL; } return 0; ... ... This is a problem because later on, we will dereference ctxt->hstate in hugetlbfs_fill_super() ... ... sb->s_blocksize = huge_page_size(ctx->hstate); ... ... Causing below Oops. Fix this by replacing cxt->hstate value only when then pagesize is known to be valid. kernel: hugetlbfs: Unsupported page size 0 MB kernel: BUG: kernel NULL pointer dereference, address: 0000000000000028 kernel: #PF: supervisor read access in kernel mode kernel: #PF: error_code(0x0000) - not-present page kernel: PGD 800000010f66c067 P4D 800000010f66c067 PUD 1b22f8067 PMD 0 kernel: Oops: 0000 [#1] PREEMPT SMP PTI kernel: CPU: 4 PID: 5659 Comm: syscall Tainted: G E 6.8.0-rc2-default+ #22 5a47c3fef76212addcc6eb71344aabc35190ae8f kernel: Hardware name: Intel Corp. GROVEPORT/GROVEPORT, BIOS GVPRCRB1.86B.0016.D04.1705030402 05/03/2017 kernel: RIP: 0010:hugetlbfs_fill_super+0xb4/0x1a0 kernel: Code: 48 8b 3b e8 3e c6 ed ff 48 85 c0 48 89 45 20 0f 84 d6 00 00 00 48 b8 ff ff ff ff ff ff ff 7f 4c 89 e7 49 89 44 24 20 48 8b 03 <8b> 48 28 b8 00 10 00 00 48 d3 e0 49 89 44 24 18 48 8b 03 8b 40 28 kernel: RSP: 0018:ffffbe9960fcbd48 EFLAGS: 00010246 kernel: RAX: 0000000000000000 RBX: ffff9af5272ae780 RCX: 0000000000372004 kernel: RDX: ffffffffffffffff RSI: ffffffffffffffff RDI: ffff9af555e9b000 kernel: RBP: ffff9af52ee66b00 R08: 0000000000000040 R09: 0000000000370004 kernel: R10: ffffbe9960fcbd48 R11: 0000000000000040 R12: ffff9af555e9b000 kernel: R13: ffffffffa66b86c0 R14: ffff9af507d2f400 R15: ffff9af507d2f400 kernel: FS: 00007ffbc0ba4740(0000) GS:ffff9b0bd7000000(0000) knlGS:0000000000000000 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kernel: CR2: 0000000000000028 CR3: 00000001b1ee0000 CR4: 00000000001506f0 kernel: Call Trace: kernel: <TASK> kernel: ? __die_body+0x1a/0x60 kernel: ? page_fault_oops+0x16f/0x4a0 kernel: ? • https://git.kernel.org/stable/c/32021982a324dce93b4ae00c06213bf45fb319c8 https://git.kernel.org/stable/c/1dde8ef4b7a749ae1bc73617c91775631d167557 https://git.kernel.org/stable/c/80d852299987a8037be145a94f41874228f1a773 https://git.kernel.org/stable/c/22850c9950a4e43a67299755d11498f3292d02ff https://git.kernel.org/stable/c/2e2c07104b4904aed1389a59b25799b95a85b5b9 https://git.kernel.org/stable/c/13c5a9fb07105557a1fa9efdb4f23d7ef30b7274 https://git.kernel.org/stable/c/ec78418801ef7b0c22cd6a30145ec480dd48db39 https://git.kernel.org/stable/c/79d72c68c58784a3e1cd2378669d51bfd •
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: -EPSS: 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') •