CVSS: -EPSS: 0%CPEs: 2EXPL: 0CVE-2024-50118 – btrfs: reject ro->rw reconfiguration if there are hard ro requirements
https://notcve.org/view.php?id=CVE-2024-50118
In the Linux kernel, the following vulnerability has been resolved: btrfs: reject ro->rw reconfiguration if there are hard ro requirements [BUG] Syzbot reports the following crash: BTRFS info (device loop0 state MCS): disabling free space tree BTRFS info (device loop0 state MCS): clearing compat-ro feature flag for FREE_SPACE_TREE (0x1) BTRFS info (device loop0 state MCS): clearing compat-ro feature flag for FREE_SPACE_TREE_VALID (0x2) Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:backup_super_roots fs/btrfs/disk-io.c:1691 [inline] RIP: 0010:write_all_supers+0x97a/0x40f0 fs/btrfs/disk-io.c:4041 Call Trace: <TASK> btrfs_commit_transaction+0x1eae/0x3740 fs/btrfs/transaction.c:2530 btrfs_delete_free_space_tree+0x383/0x730 fs/btrfs/free-space-tree.c:1312 btrfs_start_pre_rw_mount+0xf28/0x1300 fs/btrfs/disk-io.c:3012 btrfs_remount_rw fs/btrfs/super.c:1309 [inline] btrfs_reconfigure+0xae6/0x2d40 fs/btrfs/super.c:1534 btrfs_reconfigure_for_mount fs/btrfs/super.c:2020 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2079 [inline] btrfs_get_tree+0x918/0x1920 fs/btrfs/super.c:2115 vfs_get_tree+0x90/0x2b0 fs/super.c:1800 do_new_mount+0x2be/0xb40 fs/namespace.c:3472 do_mount fs/namespace.c:3812 [inline] __do_sys_mount fs/namespace.c:4020 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3997 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f [CAUSE] To support mounting different subvolume with different RO/RW flags for the new mount APIs, btrfs introduced two workaround to support this feature: - Skip mount option/feature checks if we are mounting a different subvolume - Reconfigure the fs to RW if the initial mount is RO Combining these two, we can have the following sequence: - Mount the fs ro,rescue=all,clear_cache,space_cache=v1 rescue=all will mark the fs as hard read-only, so no v2 cache clearing will happen. - Mount a subvolume rw of the same fs. We go into btrfs_get_tree_subvol(), but fc_mount() returns EBUSY because our new fc is RW, different from the original fs. Now we enter btrfs_reconfigure_for_mount(), which switches the RO flag first so that we can grab the existing fs_info. Then we reconfigure the fs to RW. - During reconfiguration, option/features check is skipped This means we will restart the v2 cache clearing, and convert back to v1 cache. This will trigger fs writes, and since the original fs has "rescue=all" option, it skips the csum tree read. And eventually causing NULL pointer dereference in super block writeback. [FIX] For reconfiguration caused by different subvolume RO/RW flags, ensure we always run btrfs_check_options() to ensure we have proper hard RO requirements met. In fact the function btrfs_check_options() doesn't really do many complex checks, but hard RO requirement and some feature dependency checks, thus there is no special reason not to do the check for mount reconfiguration. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: btrfs: rechazar la reconfiguración de ro->rw si hay requisitos de ro estrictos [ERROR]. Syzbot informa del siguiente fallo: Información de BTRFS (estado de loop0 del dispositivo MCS): deshabilitar el árbol de espacio libre Información de BTRFS (estado de loop0 del dispositivo MCS): borrando el indicador de función de compatibilidad para FREE_SPACE_TREE (0x1) Información de BTRFS (estado de loop0 del dispositivo MCS): borrando el indicador de función de compatibilidad para FREE_SPACE_TREE_VALID (0x2) Vaya: error de protección general, probablemente para la dirección no canónica 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref en el rango [0x000000000000018-0x000000000000001f] Nombre del hardware: PC estándar QEMU (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 01/04/2014 RIP: 0010:backup_super_roots fs/btrfs/disk-io.c:1691 [en línea] RIP: 0010:write_all_supers+0x97a/0x40f0 fs/btrfs/disk-io.c:4041 Seguimiento de llamadas: btrfs_commit_transaction+0x1eae/0x3740 fs/btrfs/transaction.c:2530 btrfs_delete_free_space_tree+0x383/0x730 fs/btrfs/free-space-tree.c:1312 btrfs_start_pre_rw_mount+0xf28/0x1300 fs/btrfs/disk-io.c:3012 btrfs_remount_rw fs/btrfs/super.c:1309 [en línea] btrfs_reconfigure+0xae6/0x2d40 fs/btrfs/super.c:1534 btrfs_reconfigure_for_mount fs/btrfs/super.c:2020 [en línea] btrfs_get_tree_subvol fs/btrfs/super.c:2079 [en línea] btrfs_get_tree+0x918/0x1920 fs/btrfs/super.c:2115 vfs_get_tree+0x90/0x2b0 fs/super.c:1800 do_new_mount+0x2be/0xb40 fs/namespace.c:3472 do_mount fs/namespace.c:3812 [en línea] __do_sys_mount fs/namespace.c:4020 [en línea] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3997 do_syscall_x64 arch/x86/entry/common.c:52 [en línea] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f [CAUSA] Para admitir el montaje de diferentes subvolúmenes con diferentes indicadores RO/RW para las nuevas API de montaje, btrfs introdujo dos workarounds para admitir esta función: - Omitir las comprobaciones de opciones/funciones de montaje si estamos montando un subvolumen diferente - Reconfigurar el fs a RW si el montaje inicial es RO Combinando estos dos, podemos tener la siguiente secuencia: - Montar el fs ro,rescue=all,clear_cache,space_cache=v1 rescue=all marcará el fs como de solo lectura, por lo que no se borrará la caché v2. - Montar un subvolumen rw del mismo fs. Entramos en btrfs_get_tree_subvol(), pero fc_mount() devuelve EBUSY porque nuestro nuevo fc es RW, diferente del fs original. Ahora ingresamos btrfs_reconfigure_for_mount(), que cambia el indicador RO primero para que podamos obtener el fs_info existente. • https://git.kernel.org/stable/c/f044b318675f0347ecfb88377542651ba4eb9e1f https://git.kernel.org/stable/c/23724398b55d9570f6ae79dd2ea026fff8896bf1 https://git.kernel.org/stable/c/3c36a72c1d27de6618c1c480c793d9924640f5bb •
CVSS: -EPSS: 0%CPEs: 8EXPL: 0CVE-2024-50117 – drm/amd: Guard against bad data for ATIF ACPI method
https://notcve.org/view.php?id=CVE-2024-50117
In the Linux kernel, the following vulnerability has been resolved: drm/amd: Guard against bad data for ATIF ACPI method If a BIOS provides bad data in response to an ATIF method call this causes a NULL pointer dereference in the caller. ``` ? show_regs (arch/x86/kernel/dumpstack.c:478 (discriminator 1)) ? __die (arch/x86/kernel/dumpstack.c:423 arch/x86/kernel/dumpstack.c:434) ? page_fault_oops (arch/x86/mm/fault.c:544 (discriminator 2) arch/x86/mm/fault.c:705 (discriminator 2)) ? do_user_addr_fault (arch/x86/mm/fault.c:440 (discriminator 1) arch/x86/mm/fault.c:1232 (discriminator 1)) ? • https://git.kernel.org/stable/c/d38ceaf99ed015f2a0b9af3499791bd3a3daae21 https://git.kernel.org/stable/c/58556dcbd5606a5daccaee73b2130bc16b48e025 https://git.kernel.org/stable/c/43b4fa6e0e238c6e2662f4fb61d9f51c2785fb1d https://git.kernel.org/stable/c/234682910971732cd4da96fd95946e296e486b38 https://git.kernel.org/stable/c/6032287747f874b52dc8b9d7490e2799736e035f https://git.kernel.org/stable/c/cd67af3c1762de4c2483ae4dbdd98f9ea8fa56e3 https://git.kernel.org/stable/c/975ede2a7bec52b5da1428829b3439667c8a234b https://git.kernel.org/stable/c/1d7175f9c57b1abf9ecfbdfd53ea76076 •
CVSS: -EPSS: 0%CPEs: 8EXPL: 0CVE-2024-50116 – nilfs2: fix kernel bug due to missing clearing of buffer delay flag
https://notcve.org/view.php?id=CVE-2024-50116
In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix kernel bug due to missing clearing of buffer delay flag Syzbot reported that after nilfs2 reads a corrupted file system image and degrades to read-only, the BUG_ON check for the buffer delay flag in submit_bh_wbc() may fail, causing a kernel bug. This is because the buffer delay flag is not cleared when clearing the buffer state flags to discard a page/folio or a buffer head. So, fix this. This became necessary when the use of nilfs2's own page clear routine was expanded. This state inconsistency does not occur if the buffer is written normally by log writing. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: nilfs2: se corrige un error del kernel debido a la falta de limpieza del indicador de retraso del búfer Syzbot informó que después de que nilfs2 lee una imagen de sistema de archivos corrupta y se degrada a solo lectura, la comprobación BUG_ON para el indicador de retraso del búfer en submission_bh_wbc() puede fallar, lo que provoca un error del kernel. Esto se debe a que el indicador de retraso del búfer no se borra al borrar los indicadores de estado del búfer para descartar una página/folio o un encabezado de búfer. • https://git.kernel.org/stable/c/8c26c4e2694a163d525976e804d81cd955bbb40c https://git.kernel.org/stable/c/033bc52f35868c2493a2d95c56ece7fc155d7cb3 https://git.kernel.org/stable/c/412a30b1b28d6073ba29c46a2b0f324c5936293f https://git.kernel.org/stable/c/9f2ab98371c2f2488bf3bf3f9b2a73510545e9c1 https://git.kernel.org/stable/c/822203f6355f4b322d21e7115419f6b98284be25 https://git.kernel.org/stable/c/27524f65621f490184f2ace44cd8e5f3685af4a3 https://git.kernel.org/stable/c/743c78d455e784097011ea958b27396001181567 https://git.kernel.org/stable/c/c6f58ff2d4c552927fe9a187774e668eb •
CVSS: -EPSS: 0%CPEs: 6EXPL: 0CVE-2024-50115 – KVM: nSVM: Ignore nCR3[4:0] when loading PDPTEs from memory
https://notcve.org/view.php?id=CVE-2024-50115
In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Ignore nCR3[4:0] when loading PDPTEs from memory Ignore nCR3[4:0] when loading PDPTEs from memory for nested SVM, as bits 4:0 of CR3 are ignored when PAE paging is used, and thus VMRUN doesn't enforce 32-byte alignment of nCR3. In the absolute worst case scenario, failure to ignore bits 4:0 can result in an out-of-bounds read, e.g. if the target page is at the end of a memslot, and the VMM isn't using guard pages. Per the APM: The CR3 register points to the base address of the page-directory-pointer table. The page-directory-pointer table is aligned on a 32-byte boundary, with the low 5 address bits 4:0 assumed to be 0. And the SDM's much more explicit: 4:0 Ignored Note, KVM gets this right when loading PDPTRs, it's only the nSVM flow that is broken. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: KVM: nSVM: Ignorar nCR3[4:0] al cargar PDPTE desde la memoria Ignorar nCR3[4:0] al cargar PDPTE desde la memoria para SVM anidado, ya que los bits 4:0 de CR3 se ignoran cuando se utiliza la paginación PAE y, por lo tanto, VMRUN no aplica la alineación de 32 bytes de nCR3. En el peor de los casos, no ignorar los bits 4:0 puede dar como resultado una lectura fuera de los límites, por ejemplo, si la página de destino está al final de un memslot y el VMM no está utilizando páginas de protección. Según el APM: El registro CR3 apunta a la dirección base de la tabla de punteros de directorio de páginas. • https://git.kernel.org/stable/c/e4e517b4be019787ada4cbbce2f04570c21b0cbd https://git.kernel.org/stable/c/76ce386feb14ec9a460784fcd495d8432acce7a5 https://git.kernel.org/stable/c/58cb697d80e669c56197f703e188867c8c54c494 https://git.kernel.org/stable/c/6876793907cbe19d42e9edc8c3315a21e06c32ae https://git.kernel.org/stable/c/2c4adc9b192a0815fe58a62bc0709449416cc884 https://git.kernel.org/stable/c/426682afec71ea3f889b972d038238807b9443e4 https://git.kernel.org/stable/c/f559b2e9c5c5308850544ab59396b7d53cfc67bd •
CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2024-50112 – x86/lam: Disable ADDRESS_MASKING in most cases
https://notcve.org/view.php?id=CVE-2024-50112
In the Linux kernel, the following vulnerability has been resolved: x86/lam: Disable ADDRESS_MASKING in most cases Linear Address Masking (LAM) has a weakness related to transient execution as described in the SLAM paper[1]. Unless Linear Address Space Separation (LASS) is enabled this weakness may be exploitable. Until kernel adds support for LASS[2], only allow LAM for COMPILE_TEST, or when speculation mitigations have been disabled at compile time, otherwise keep LAM disabled. There are no processors in market that support LAM yet, so currently nobody is affected by this issue. [1] SLAM: https://download.vusec.net/papers/slam_sp24.pdf [2] LASS: https://lore.kernel.org/lkml/20230609183632.48706-1-alexander.shishkin@linux.intel.com/ [ dhansen: update SPECULATION_MITIGATIONS -> CPU_MITIGATIONS ] En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: x86/lam: Deshabilitar ADDRESS_MASKING en la mayoría de los casos. El enmascaramiento de direcciones lineales (LAM) tiene una debilidad relacionada con la ejecución transitoria como se describe en el documento SLAM[1]. A menos que se habilite la separación del espacio de direcciones lineales (LASS), esta debilidad puede ser explotable. Hasta que el kernel agregue soporte para LASS[2], solo permita LAM para COMPILE_TEST, o cuando las mitigaciones de especulación se hayan deshabilitado en el momento de la compilación, de lo contrario, mantenga LAM deshabilitado. • https://git.kernel.org/stable/c/60a5ba560f296ad8da153f6ad3f70030bfa3958f https://git.kernel.org/stable/c/690599066488d16db96ac0d6340f9372fc56f337 https://git.kernel.org/stable/c/3267cb6d3a174ff83d6287dcd5b0047bbd912452 •