CVSS: 5.5EPSS: 0%CPEs: 3EXPL: 0CVE-2021-47492 – mm, thp: bail out early in collapse_file for writeback page
https://notcve.org/view.php?id=CVE-2021-47492
In the Linux kernel, the following vulnerability has been resolved: mm, thp: bail out early in collapse_file for writeback page Currently collapse_file does not explicitly check PG_writeback, instead, page_has_private and try_to_release_page are used to filter writeback pages. This does not work for xfs with blocksize equal to or larger than pagesize, because in such case xfs has no page->private. This makes collapse_file bail out early for writeback page. Otherwise, xfs end_page_writeback will panic as follows. page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:ffff0003f88c86a8 index:0x0 pfn:0x84ef32 aops:xfs_address_space_operations [xfs] ino:30000b7 dentry name:"libtest.so" flags: 0x57fffe0000008027(locked|referenced|uptodate|active|writeback) raw: 57fffe0000008027 ffff80001b48bc28 ffff80001b48bc28 ffff0003f88c86a8 raw: 0000000000000000 0000000000000000 00000000ffffffff ffff0000c3e9a000 page dumped because: VM_BUG_ON_PAGE(((unsigned int) page_ref_count(page) + 127u <= 127u)) page->mem_cgroup:ffff0000c3e9a000 ------------[ cut here ]------------ kernel BUG at include/linux/mm.h:1212! Internal error: Oops - BUG: 0 [#1] SMP Modules linked in: BUG: Bad page state in process khugepaged pfn:84ef32 xfs(E) page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:0 index:0x0 pfn:0x84ef32 libcrc32c(E) rfkill(E) aes_ce_blk(E) crypto_simd(E) ... CPU: 25 PID: 0 Comm: swapper/25 Kdump: loaded Tainted: ... pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--) Call trace: end_page_writeback+0x1c0/0x214 iomap_finish_page_writeback+0x13c/0x204 iomap_finish_ioend+0xe8/0x19c iomap_writepage_end_bio+0x38/0x50 bio_endio+0x168/0x1ec blk_update_request+0x278/0x3f0 blk_mq_end_request+0x34/0x15c virtblk_request_done+0x38/0x74 [virtio_blk] blk_done_softirq+0xc4/0x110 __do_softirq+0x128/0x38c __irq_exit_rcu+0x118/0x150 irq_exit+0x1c/0x30 __handle_domain_irq+0x8c/0xf0 gic_handle_irq+0x84/0x108 el1_irq+0xcc/0x180 arch_cpu_idle+0x18/0x40 default_idle_call+0x4c/0x1a0 cpuidle_idle_call+0x168/0x1e0 do_idle+0xb4/0x104 cpu_startup_entry+0x30/0x9c secondary_start_kernel+0x104/0x180 Code: d4210000 b0006161 910c8021 94013f4d (d4210000) ---[ end trace 4a88c6a074082f8c ]--- Kernel panic - not syncing: Oops - BUG: Fatal exception in interrupt En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mm, thp: rescatar temprano en el colapso_archivo para la página de reescritura. Actualmente, colapso_archivo no verifica explícitamente PG_writeback; en su lugar, page_has_private y try_to_release_page se utilizan para filtrar las páginas de reescritura. • https://git.kernel.org/stable/c/99cb0dbd47a15d395bf3faa78dc122bc5efe3fc0 https://git.kernel.org/stable/c/69a7fa5cb0de06c8956b040f19a7248c8c8308ca https://git.kernel.org/stable/c/5e669d8ab30ab61dec3c36e27b4711f07611e6fc https://git.kernel.org/stable/c/74c42e1baacf206338b1dd6b6199ac964512b5bb https://access.redhat.com/security/cve/CVE-2021-47492 https://bugzilla.redhat.com/show_bug.cgi?id=2282924 • CWE-372: Incomplete Internal State Distinction •
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 •