CVSS: -EPSS: 0%CPEs: 8EXPL: 0CVE-2021-47276 – ftrace: Do not blindly read the ip address in ftrace_bug()
https://notcve.org/view.php?id=CVE-2021-47276
In the Linux kernel, the following vulnerability has been resolved: ftrace: Do not blindly read the ip address in ftrace_bug() It was reported that a bug on arm64 caused a bad ip address to be used for updating into a nop in ftrace_init(), but the error path (rightfully) returned -EINVAL and not -EFAULT, as the bug caused more than one error to occur. But because -EINVAL was returned, the ftrace_bug() tried to report what was at the location of the ip address, and read it directly. This caused the machine to panic, as the ip was not pointing to a valid memory address. Instead, read the ip address with copy_from_kernel_nofault() to safely access the memory, and if it faults, report that the address faulted, otherwise report what was in that location. En el kernel de Linux, se resolvió la siguiente vulnerabilidad: ftrace: no lea ciegamente la dirección IP en ftrace_bug(). Se informó que un error en arm64 provocó que se usara una dirección IP incorrecta para actualizar a un nop en ftrace_init() , pero la ruta de error (con razón) devolvió -EINVAL y no -EFAULT, ya que el error provocó que ocurriera más de un error. • https://git.kernel.org/stable/c/05736a427f7e16be948ccbf39782bd3a6ae16b14 https://git.kernel.org/stable/c/0bc62e398bbd9e600959e610def5109957437b28 https://git.kernel.org/stable/c/4aedc2bc2b32c93555f47c95610efb89cc1ec09b https://git.kernel.org/stable/c/acf671ba79c1feccc3ec7cfdcffead4efcec49e7 https://git.kernel.org/stable/c/862dcc14f2803c556bdd73b43c27b023fafce2fb https://git.kernel.org/stable/c/7e4e824b109f1d41ccf223fbb0565d877d6223a2 https://git.kernel.org/stable/c/97524384762c1fb9b3ded931498dd2047bd0de81 https://git.kernel.org/stable/c/3e4ddeb68751fb4fb657199aed9cfd5d0 •
CVSS: -EPSS: 0%CPEs: 2EXPL: 0CVE-2021-47275 – bcache: avoid oversized read request in cache missing code path
https://notcve.org/view.php?id=CVE-2021-47275
In the Linux kernel, the following vulnerability has been resolved: bcache: avoid oversized read request in cache missing code path In the cache missing code path of cached device, if a proper location from the internal B+ tree is matched for a cache miss range, function cached_dev_cache_miss() will be called in cache_lookup_fn() in the following code block, [code block 1] 526 unsigned int sectors = KEY_INODE(k) == s->iop.inode 527 ? min_t(uint64_t, INT_MAX, 528 KEY_START(k) - bio->bi_iter.bi_sector) 529 : INT_MAX; 530 int ret = s->d->cache_miss(b, s, bio, sectors); Here s->d->cache_miss() is the call backfunction pointer initialized as cached_dev_cache_miss(), the last parameter 'sectors' is an important hint to calculate the size of read request to backing device of the missing cache data. Current calculation in above code block may generate oversized value of 'sectors', which consequently may trigger 2 different potential kernel panics by BUG() or BUG_ON() as listed below, 1) BUG_ON() inside bch_btree_insert_key(), [code block 2] 886 BUG_ON(b->ops->is_extents && !KEY_SIZE(k)); 2) BUG() inside biovec_slab(), [code block 3] 51 default: 52 BUG(); 53 return NULL; All the above panics are original from cached_dev_cache_miss() by the oversized parameter 'sectors'. Inside cached_dev_cache_miss(), parameter 'sectors' is used to calculate the size of data read from backing device for the cache missing. This size is stored in s->insert_bio_sectors by the following lines of code, [code block 4] 909 s->insert_bio_sectors = min(sectors, bio_sectors(bio) + reada); Then the actual key inserting to the internal B+ tree is generated and stored in s->iop.replace_key by the following lines of code, [code block 5] 911 s->iop.replace_key = KEY(s->iop.inode, 912 bio->bi_iter.bi_sector + s->insert_bio_sectors, 913 s->insert_bio_sectors); The oversized parameter 'sectors' may trigger panic 1) by BUG_ON() from the above code block. And the bio sending to backing device for the missing data is allocated with hint from s->insert_bio_sectors by the following lines of code, [code block 6] 926 cache_bio = bio_alloc_bioset(GFP_NOWAIT, 927 DIV_ROUND_UP(s->insert_bio_sectors, PAGE_SECTORS), 928 &dc->disk.bio_split); The oversized parameter 'sectors' may trigger panic 2) by BUG() from the agove code block. Now let me explain how the panics happen with the oversized 'sectors'. In code block 5, replace_key is generated by macro KEY(). From the definition of macro KEY(), [code block 7] 71 #define KEY(inode, offset, size) \ 72 ((struct bkey) { \ 73 .high = (1ULL << 63) | ((__u64) (size) << 20) | (inode), \ 74 .low = (offset) \ 75 }) Here 'size' is 16bits width embedded in 64bits member 'high' of struct bkey. • https://git.kernel.org/stable/c/555002a840ab88468e252b0eedf0b05e2ce7099c https://git.kernel.org/stable/c/41fe8d088e96472f63164e213de44ec77be69478 •
CVSS: 9.8EPSS: 0%CPEs: 7EXPL: 0CVE-2021-47274 – tracing: Correct the length check which causes memory corruption
https://notcve.org/view.php?id=CVE-2021-47274
In the Linux kernel, the following vulnerability has been resolved: tracing: Correct the length check which causes memory corruption We've suffered from severe kernel crashes due to memory corruption on our production environment, like, Call Trace: [1640542.554277] general protection fault: 0000 [#1] SMP PTI [1640542.554856] CPU: 17 PID: 26996 Comm: python Kdump: loaded Tainted:G [1640542.556629] RIP: 0010:kmem_cache_alloc+0x90/0x190 [1640542.559074] RSP: 0018:ffffb16faa597df8 EFLAGS: 00010286 [1640542.559587] RAX: 0000000000000000 RBX: 0000000000400200 RCX: 0000000006e931bf [1640542.560323] RDX: 0000000006e931be RSI: 0000000000400200 RDI: ffff9a45ff004300 [1640542.560996] RBP: 0000000000400200 R08: 0000000000023420 R09: 0000000000000000 [1640542.561670] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff9a20608d [1640542.562366] R13: ffff9a45ff004300 R14: ffff9a45ff004300 R15: 696c662f65636976 [1640542.563128] FS: 00007f45d7c6f740(0000) GS:ffff9a45ff840000(0000) knlGS:0000000000000000 [1640542.563937] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [1640542.564557] CR2: 00007f45d71311a0 CR3: 000000189d63e004 CR4: 00000000003606e0 [1640542.565279] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [1640542.566069] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [1640542.566742] Call Trace: [1640542.567009] anon_vma_clone+0x5d/0x170 [1640542.567417] __split_vma+0x91/0x1a0 [1640542.567777] do_munmap+0x2c6/0x320 [1640542.568128] vm_munmap+0x54/0x70 [1640542.569990] __x64_sys_munmap+0x22/0x30 [1640542.572005] do_syscall_64+0x5b/0x1b0 [1640542.573724] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [1640542.575642] RIP: 0033:0x7f45d6e61e27 James Wang has reproduced it stably on the latest 4.19 LTS. After some debugging, we finally proved that it's due to ftrace buffer out-of-bound access using a debug tool as follows: [ 86.775200] BUG: Out-of-bounds write at addr 0xffff88aefe8b7000 [ 86.780806] no_context+0xdf/0x3c0 [ 86.784327] __do_page_fault+0x252/0x470 [ 86.788367] do_page_fault+0x32/0x140 [ 86.792145] page_fault+0x1e/0x30 [ 86.795576] strncpy_from_unsafe+0x66/0xb0 [ 86.799789] fetch_memory_string+0x25/0x40 [ 86.804002] fetch_deref_string+0x51/0x60 [ 86.808134] kprobe_trace_func+0x32d/0x3a0 [ 86.812347] kprobe_dispatcher+0x45/0x50 [ 86.816385] kprobe_ftrace_handler+0x90/0xf0 [ 86.820779] ftrace_ops_assist_func+0xa1/0x140 [ 86.825340] 0xffffffffc00750bf [ 86.828603] do_sys_open+0x5/0x1f0 [ 86.832124] do_syscall_64+0x5b/0x1b0 [ 86.835900] entry_SYSCALL_64_after_hwframe+0x44/0xa9 commit b220c049d519 ("tracing: Check length before giving out the filter buffer") adds length check to protect trace data overflow introduced in 0fc1b09ff1ff, seems that this fix can't prevent overflow entirely, the length check should also take the sizeof entry->array[0] into account, since this array[0] is filled the length of trace data and occupy addtional space and risk overflow. En el kernel de Linux, se resolvió la siguiente vulnerabilidad: rastreo: corrija la verificación de longitud que causa corrupción de la memoria. Hemos sufrido fallos graves del kernel debido a la corrupción de la memoria en nuestro entorno de producción, como Call Trace: [1640542.554277] fallo de protección general. : 0000 [#1] SMP PTI [1640542.554856] CPU: 17 PID: 26996 Comm: python Kdump: cargado Contaminado:G [1640542.556629] RIP: 0010:kmem_cache_alloc+0x90/0x190 [1640542.559074] : 0018:ffffb16faa597df8 EFLAGS: 00010286 [ 1640542.559587] RAX: 0000000000000000 RBX: 0000000000400200 RCX: 0000000006e931bf [1640542.560323] RDX: 0000000006e931be RSI: 0000400200 RDI: ffff9a45ff004300 [1640542.560996] RBP: 0000000000400200 R08: 0000000000023420 R09: 0000000000000000 [1640542.561670] : 0000000000000000 R11: 0000000000000000 R12: ffffffff9a20608d [1640542.562366] R13: ffff9a45ff004300 R14: ffff9a45ff004300 R15: 696c662f65636976 [1640542.563128] FS: 00007f45d7c6f740(0000) GS:ffff9a45ff840000(0000) GS:0000000000000000 [1640542.563937] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [1640542.564557] CR2: 00007f45d71311a0 CR3: 000000189d63e004 CR4: 00000000003606e0 [1640542.565279] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [1640542.5 66069] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [1640542.566742] Seguimiento de llamadas: [1640542.567009] anon_vma_clone+0x5d/0x170 2.567417] __split_vma+0x91/0x1a0 [1640542.567777] do_munmap+0x2c6/0x320 [1640542.568128] vm_munmap+0x54/0x70 [1640542.569990] __x64_sys_munmap+0x22/0x30 [1640542.572005] _64+0x5b/0x1b0 [1640542.573724] entrada_SYSCALL_64_after_hwframe+0x44/0xa9 [1640542.575642] RIP: 0033:0x7f45d6e61e27 James Wang lo ha reproducido de forma estable en la última versión 4.19 LTS. Después de algunas depuraciones, finalmente demostramos que se debe al acceso fuera de los límites al búfer ftrace usando una herramienta de depuración de la siguiente manera: [86.775200] ERROR: Escritura fuera de los límites en la dirección 0xffff88aefe8b7000 [86.780806] no_context+0xdf/0x3c0 [86.784327 ] __do_page_fault+0x252/0x470 [ 86.788367] do_page_fault+0x32/0x140 [ 86.792145] page_fault+0x1e/0x30 [ 86.795576] strncpy_from_unsafe+0x66/0xb0 [ 86.799789] ry_string+0x25/0x40 [ 86.804002] fetch_deref_string+0x51/0x60 [ 86.808134] kprobe_trace_func +0x32d/0x3a0 [ 86.812347] kprobe_dispatcher+0x45/0x50 [ 86.816385] kprobe_ftrace_handler+0x90/0xf0 [ 86.820779] ftrace_ops_assist_func+0xa1/0x140 [ 86.825340] ffffc00750bf [ 86.828603] do_sys_open+0x5/0x1f0 [ 86.832124] do_syscall_64+0x5b/0x1b0 [ 86.835900 ] Entry_SYSCALL_64_after_hwframe+0x44/0xa9 commit b220c049d519 ("rastreo: verificar la longitud antes de entregar el búfer de filtro") agrega verificación de longitud para proteger el desbordamiento de datos de seguimiento introducido en 0fc1b09ff1ff, parece que esta solución no puede evitar el desbordamiento por completo, la verificación de longitud también debería tenga en cuenta el tamaño de la entrada->matriz[0], ya que esta matriz[0] ocupa toda la longitud de los datos de seguimiento y ocupa espacio adicional y corre el riesgo de desbordarse. • https://git.kernel.org/stable/c/2e584b1a02eeb860e286d39bc408b25ebc5ec844 https://git.kernel.org/stable/c/e46d433754420b4d6513ca389403de88a0910279 https://git.kernel.org/stable/c/0572fc6a510add9029b113239eaabf4b5bce8ec9 https://git.kernel.org/stable/c/a0997a86f5c0085e183ddee5fb72091d584d3d16 https://git.kernel.org/stable/c/7c93d8cff582c459350d6f8906eea6e4cd60d959 https://git.kernel.org/stable/c/b220c049d5196dd94d992dd2dc8cba1a5e6123bf https://git.kernel.org/stable/c/edcce01e0e50840a9aa6a70baed21477bdd2c9f9 https://git.kernel.org/stable/c/2d598902799886d67947406f26ee8e5fd • CWE-125: Out-of-bounds Read •
CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2021-47273 – usb: dwc3-meson-g12a: fix usb2 PHY glue init when phy0 is disabled
https://notcve.org/view.php?id=CVE-2021-47273
In the Linux kernel, the following vulnerability has been resolved: usb: dwc3-meson-g12a: fix usb2 PHY glue init when phy0 is disabled When only PHY1 is used (for example on Odroid-HC4), the regmap init code uses the usb2 ports when doesn't initialize the PHY1 regmap entry. This fixes: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 ... pc : regmap_update_bits_base+0x40/0xa0 lr : dwc3_meson_g12a_usb2_init_phy+0x4c/0xf8 ... Call trace: regmap_update_bits_base+0x40/0xa0 dwc3_meson_g12a_usb2_init_phy+0x4c/0xf8 dwc3_meson_g12a_usb2_init+0x7c/0xc8 dwc3_meson_g12a_usb_init+0x28/0x48 dwc3_meson_g12a_probe+0x298/0x540 platform_probe+0x70/0xe0 really_probe+0xf0/0x4d8 driver_probe_device+0xfc/0x168 ... En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: usb: dwc3-meson-g12a: repara el init de glue PHY de usb2 cuando phy0 está deshabilitado. Cuando solo se usa PHY1 (por ejemplo, en Odroid-HC4), el código de inicio de regmap usa usb2 puertos cuando no inicializa la entrada del mapa de registro PHY1. Esto soluciona: No se puede manejar la desreferencia del puntero NULL del kernel en la dirección virtual 0000000000000020... pc: regmap_update_bits_base+0x40/0xa0 lr: dwc3_meson_g12a_usb2_init_phy+0x4c/0xf8... Seguimiento de llamadas: regmap_update_bits_base+0x40/0xa0 g12a_usb2_init_phy+0x4c/0xf8 dwc3_meson_g12a_usb2_init+0x7c /0xc8 dwc3_meson_g12a_usb_init+0x28/0x48 dwc3_meson_g12a_probe+0x298/0x540 platform_probe+0x70/0xe0 Actually_probe+0xf0/0x4d8 driver_probe_device+0xfc/0x168 ... • https://git.kernel.org/stable/c/013af227f58a97ffc61b99301f8f4448dc7e7f55 https://git.kernel.org/stable/c/750a0d75564293be3ed50f13ef7f38ab75106421 https://git.kernel.org/stable/c/d8dd3754e707104a34f8ec595034d503ea8871a2 https://git.kernel.org/stable/c/4d2aa178d2ad2fb156711113790dde13e9aa2376 •
CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2021-47272 – usb: dwc3: gadget: Bail from dwc3_gadget_exit() if dwc->gadget is NULL
https://notcve.org/view.php?id=CVE-2021-47272
In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: gadget: Bail from dwc3_gadget_exit() if dwc->gadget is NULL There exists a possible scenario in which dwc3_gadget_init() can fail: during during host -> peripheral mode switch in dwc3_set_mode(), and a pending gadget driver fails to bind. Then, if the DRD undergoes another mode switch from peripheral->host the resulting dwc3_gadget_exit() will attempt to reference an invalid and dangling dwc->gadget pointer as well as call dma_free_coherent() on unmapped DMA pointers. The exact scenario can be reproduced as follows: - Start DWC3 in peripheral mode - Configure ConfigFS gadget with FunctionFS instance (or use g_ffs) - Run FunctionFS userspace application (open EPs, write descriptors, etc) - Bind gadget driver to DWC3's UDC - Switch DWC3 to host mode => dwc3_gadget_exit() is called. usb_del_gadget() will put the ConfigFS driver instance on the gadget_driver_pending_list - Stop FunctionFS application (closes the ep files) - Switch DWC3 to peripheral mode => dwc3_gadget_init() fails as usb_add_gadget() calls check_pending_gadget_drivers() and attempts to rebind the UDC to the ConfigFS gadget but fails with -19 (-ENODEV) because the FFS instance is not in FFS_ACTIVE state (userspace has not re-opened and written the descriptors yet, i.e. desc_ready!=0). - Switch DWC3 back to host mode => dwc3_gadget_exit() is called again, but this time dwc->gadget is invalid. Although it can be argued that userspace should take responsibility for ensuring that the FunctionFS application be ready prior to allowing the composite driver bind to the UDC, failure to do so should not result in a panic from the kernel driver. Fix this by setting dwc->gadget to NULL in the failure path of dwc3_gadget_init() and add a check to dwc3_gadget_exit() to bail out unless the gadget pointer is valid. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: usb: dwc3: gadget: Bail from dwc3_gadget_exit() si dwc->gadget es NULL. Existe un posible escenario en el que dwc3_gadget_init() puede fallar: durante durante el host -> modo periférico Cambie a dwc3_set_mode() y un controlador de dispositivo pendiente no se vincula. • https://git.kernel.org/stable/c/e81a7018d93a7de31a3f121c9a7eecd0a5ec58b0 https://git.kernel.org/stable/c/851dee5a5da56564a70290713aee665403bb0b24 https://git.kernel.org/stable/c/4aad390363d2b9b3e92428dd34d27bb7ea8f1ee8 https://git.kernel.org/stable/c/03715ea2e3dbbc56947137ce3b4ac18a726b2f87 •