CVSS: 5.5EPSS: 0%CPEs: 3EXPL: 0CVE-2021-47491 – mm: khugepaged: skip huge page collapse for special files
https://notcve.org/view.php?id=CVE-2021-47491
In the Linux kernel, the following vulnerability has been resolved: mm: khugepaged: skip huge page collapse for special files The read-only THP for filesystems will collapse THP for files opened readonly and mapped with VM_EXEC. The intended usecase is to avoid TLB misses for large text segments. But it doesn't restrict the file types so a THP could be collapsed for a non-regular file, for example, block device, if it is opened readonly and mapped with EXEC permission. This may cause bugs, like [1] and [2]. This is definitely not the intended usecase, so just collapse THP for regular files in order to close the attack surface. [shy828301@gmail.com: fix vm_file check [3]] En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mm: khugepaged: omitir el colapso de página enorme para archivos especiales El THP de solo lectura para sistemas de archivos colapsará el THP para archivos abiertos de solo lectura y asignados con VM_EXEC. El caso de uso previsto es evitar errores de TLB en segmentos de texto grandes. • https://git.kernel.org/stable/c/99cb0dbd47a15d395bf3faa78dc122bc5efe3fc0 https://git.kernel.org/stable/c/6d67b2a73b8e3a079c355bab3c1aef7d85a044b8 https://git.kernel.org/stable/c/5fcb6fce74ffa614d964667110cf1a516c48c6d9 https://git.kernel.org/stable/c/a4aeaa06d45e90f9b279f0b09de84bd00006e733 https://access.redhat.com/security/cve/CVE-2021-47491 https://bugzilla.redhat.com/show_bug.cgi?id=2282925 • CWE-664: Improper Control of a Resource Through its Lifetime •
CVSS: -EPSS: 0%CPEs: 6EXPL: 0CVE-2021-47490 – drm/ttm: fix memleak in ttm_transfered_destroy
https://notcve.org/view.php?id=CVE-2021-47490
In the Linux kernel, the following vulnerability has been resolved: drm/ttm: fix memleak in ttm_transfered_destroy We need to cleanup the fences for ghost objects as well. Bug: https://bugzilla.kernel.org/show_bug.cgi?id=214029 Bug: https://bugzilla.kernel.org/show_bug.cgi?id=214447 En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: drm/ttm: corrige memleak en ttm_transfered_destroy También necesitamos limpiar las barreras para detectar objetos fantasma. Error: https://bugzilla.kernel.org/show_bug.cgi?id=214029 Error: https://bugzilla.kernel.org/show_bug.cgi? • https://git.kernel.org/stable/c/bd99782f3ca491879e8524c89b1c0f40071903bd https://git.kernel.org/stable/c/960b1fdfc39aba8f41e9e27b2de0c925c74182d9 https://git.kernel.org/stable/c/c21b4002214c1c7e7b627b9b53375612f7aab6db https://git.kernel.org/stable/c/bbc920fb320f1c241cc34ac85edaa0058922246a https://git.kernel.org/stable/c/132a3d998d6753047f22152731fba2b0d6b463dd https://git.kernel.org/stable/c/0db55f9a1bafbe3dac750ea669de9134922389b5 •
CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2021-47488 – cgroup: Fix memory leak caused by missing cgroup_bpf_offline
https://notcve.org/view.php?id=CVE-2021-47488
In the Linux kernel, the following vulnerability has been resolved: cgroup: Fix memory leak caused by missing cgroup_bpf_offline When enabling CONFIG_CGROUP_BPF, kmemleak can be observed by running the command as below: $mount -t cgroup -o none,name=foo cgroup cgroup/ $umount cgroup/ unreferenced object 0xc3585c40 (size 64): comm "mount", pid 425, jiffies 4294959825 (age 31.990s) hex dump (first 32 bytes): 01 00 00 80 84 8c 28 c0 00 00 00 00 00 00 00 00 ......(......... 00 00 00 00 00 00 00 00 6c 43 a0 c3 00 00 00 00 ........lC...... backtrace: [<e95a2f9e>] cgroup_bpf_inherit+0x44/0x24c [<1f03679c>] cgroup_setup_root+0x174/0x37c [<ed4b0ac5>] cgroup1_get_tree+0x2c0/0x4a0 [<f85b12fd>] vfs_get_tree+0x24/0x108 [<f55aec5c>] path_mount+0x384/0x988 [<e2d5e9cd>] do_mount+0x64/0x9c [<208c9cfe>] sys_mount+0xfc/0x1f4 [<06dd06e0>] ret_fast_syscall+0x0/0x48 [<a8308cb3>] 0xbeb4daa8 This is because that since the commit 2b0d3d3e4fcf ("percpu_ref: reduce memory footprint of percpu_ref in fast path") root_cgrp->bpf.refcnt.data is allocated by the function percpu_ref_init in cgroup_bpf_inherit which is called by cgroup_setup_root when mounting, but not freed along with root_cgrp when umounting. Adding cgroup_bpf_offline which calls percpu_ref_kill to cgroup_kill_sb can free root_cgrp->bpf.refcnt.data in umount path. This patch also fixes the commit 4bfc0bb2c60e ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself"). A cgroup_bpf_offline is needed to do a cleanup that frees the resources which are allocated by cgroup_bpf_inherit in cgroup_setup_root. And inside cgroup_bpf_offline, cgroup_get() is at the beginning and cgroup_put is at the end of cgroup_bpf_release which is called by cgroup_bpf_offline. So cgroup_bpf_offline can keep the balance of cgroup's refcount. En el kernel de Linux, se resolvió la siguiente vulnerabilidad: cgroup: corrige la pérdida de memoria causada por la falta de cgroup_bpf_offline Al habilitar CONFIG_CGROUP_BPF, se puede observar kmemleak ejecutando el siguiente comando: $mount -t cgroup -o none,name=foo cgroup cgroup / $umount cgroup/ objeto sin referencia 0xc3585c40 (tamaño 64): comm "mount", pid 425, sjiffies 4294959825 (edad 31.990s) volcado hexadecimal (primeros 32 bytes): 01 00 00 80 84 8c 28 c0 00 00 00 00 00 00 00 00 ......(....... 00 00 00 00 00 00 00 00 6c 43 a0 c3 00 00 00 00 ........lC...... retroceso : [] cgroup_bpf_inherit+0x44/0x24c [<1f03679c>] cgroup_setup_root+0x174/0x37c [] cgroup1_get_tree+0x2c0/0x4a0 [] 8 [] ruta_montaje+0x384/ 0x988 [] do_mount+0x64/0x9c [<208c9cfe>] sys_mount+0xfc/0x1f4 [<06dd06e0>] ret_fast_syscall+0x0/0x48 [] 0xbeb4daa8 Esto se debe a que desde El commit 2b0d3d3e4f cf ("percpu_ref: reducir huella de memoria de percpu_ref en la ruta rápida") root_cgrp->bpf.refcnt.data es asignada por la función percpu_ref_init en cgroup_bpf_inherit, que es llamada por cgroup_setup_root al montar, pero no se libera junto con root_cgrp al desmontar. • https://git.kernel.org/stable/c/4bfc0bb2c60e2f4cc8eb60f03cf8dfa72336272a https://git.kernel.org/stable/c/01599bf7cc2b49c3d2be886cb438647dc25446ed https://git.kernel.org/stable/c/b529f88d93884cf8ccafda793ee3d27b82fa578d https://git.kernel.org/stable/c/04f8ef5643bcd8bcde25dfdebef998aea480b2ba •
CVSS: -EPSS: 0%CPEs: 8EXPL: 0CVE-2021-47485 – IB/qib: Protect from buffer overflow in struct qib_user_sdma_pkt fields
https://notcve.org/view.php?id=CVE-2021-47485
In the Linux kernel, the following vulnerability has been resolved: IB/qib: Protect from buffer overflow in struct qib_user_sdma_pkt fields Overflowing either addrlimit or bytes_togo can allow userspace to trigger a buffer overflow of kernel memory. Check for overflows in all the places doing math on user controlled buffers. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: IB/qib: Protege contra el desbordamiento del búfer en los campos de struct qib_user_sdma_pkt. El desbordamiento de addrlimit o bytes_togo puede permitir que el espacio de usuario desencadene un desbordamiento del búfer de la memoria del kernel. Compruebe si hay desbordamientos en todos los lugares que realizan cálculos en búferes controlados por el usuario. • https://git.kernel.org/stable/c/f931551bafe1f10ded7f5282e2aa162c267a2e5d https://git.kernel.org/stable/c/bda41654b6e0c125a624ca35d6d20beb8015b5d0 https://git.kernel.org/stable/c/3f57c3f67fd93b4da86aeffea1ca32c484d054ad https://git.kernel.org/stable/c/60833707b968d5ae02a75edb7886dcd4a957cf0d https://git.kernel.org/stable/c/73d2892148aa4397a885b4f4afcfc5b27a325c42 https://git.kernel.org/stable/c/0f8cdfff06829a0b0348b6debc29ff6a61967724 https://git.kernel.org/stable/c/c3e17e58f571f34c51aeb17274ed02c2ed5cf780 https://git.kernel.org/stable/c/0d4395477741608d123dad51def9fe50b •
CVSS: -EPSS: 0%CPEs: 8EXPL: 0CVE-2021-47483 – regmap: Fix possible double-free in regcache_rbtree_exit()
https://notcve.org/view.php?id=CVE-2021-47483
In the Linux kernel, the following vulnerability has been resolved: regmap: Fix possible double-free in regcache_rbtree_exit() In regcache_rbtree_insert_to_block(), when 'present' realloc failed, the 'blk' which is supposed to assign to 'rbnode->block' will be freed, so 'rbnode->block' points a freed memory, in the error handling path of regcache_rbtree_init(), 'rbnode->block' will be freed again in regcache_rbtree_exit(), KASAN will report double-free as follows: BUG: KASAN: double-free or invalid-free in kfree+0xce/0x390 Call Trace: slab_free_freelist_hook+0x10d/0x240 kfree+0xce/0x390 regcache_rbtree_exit+0x15d/0x1a0 regcache_rbtree_init+0x224/0x2c0 regcache_init+0x88d/0x1310 __regmap_init+0x3151/0x4a80 __devm_regmap_init+0x7d/0x100 madera_spi_probe+0x10f/0x333 [madera_spi] spi_probe+0x183/0x210 really_probe+0x285/0xc30 To fix this, moving up the assignment of rbnode->block to immediately after the reallocation has succeeded so that the data structure stays valid even if the second reallocation fails. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: regmap: corrige posible doble liberación en regcache_rbtree_exit() En regcache_rbtree_insert_to_block(), cuando la realloc 'presente' fallaba, el 'blk' que se supone debe asignarse a 'rbnode->block ' se liberará, por lo que 'rbnode->block' apunta a una memoria liberada, en la ruta de manejo de errores de regcache_rbtree_init(), 'rbnode->block' se liberará nuevamente en regcache_rbtree_exit(), KASAN informará la doble liberación de la siguiente manera : ERROR: KASAN: doble libre o no válido en kfree+0xce/0x390 Rastreo de llamadas: slab_free_freelist_hook+0x10d/0x240 kfree+0xce/0x390 regcache_rbtree_exit+0x15d/0x1a0 regcache_rbtree_init+0x224/0x2c0 regcache_init+0x88d/ 0x1310 __regmap_init+0x3151/ 0x4a80 __devm_regmap_init+0x7d/0x100 madera_spi_probe+0x10f/0x333 [madera_spi] spi_probe+0x183/0x210 Actually_probe+0x285/0xc30 Para solucionar este problema, mueva hacia arriba la asignación de rbnode->block inmediatamente después de que la reasignación se haya realizado correctamente para que la estructura de datos permanezca válido incluso si la segunda reasignación falla. • https://git.kernel.org/stable/c/3f4ff561bc88b074d5e868dde4012d89cbb06c87 https://git.kernel.org/stable/c/e72dce9afbdbfa70d9b44f5908a50ff6c4858999 https://git.kernel.org/stable/c/fc081477b47dfc3a6cb50a96087fc29674013fc2 https://git.kernel.org/stable/c/758ced2c3878ff789801e6fee808e185c5cf08d6 https://git.kernel.org/stable/c/3dae1a4eced3ee733d7222e69b8a55caf2d61091 https://git.kernel.org/stable/c/1cead23c1c0bc766dacb900a3b0269f651ad596f https://git.kernel.org/stable/c/36e911a16b377bde0ad91a8c679069d0d310b1a6 https://git.kernel.org/stable/c/50cc1462a668dc62949a1127388bc3af7 •