CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2024-35878 – of: module: prevent NULL pointer dereference in vsnprintf()
https://notcve.org/view.php?id=CVE-2024-35878
In the Linux kernel, the following vulnerability has been resolved: of: module: prevent NULL pointer dereference in vsnprintf() In of_modalias(), we can get passed the str and len parameters which would cause a kernel oops in vsnprintf() since it only allows passing a NULL ptr when the length is also 0. Also, we need to filter out the negative values of the len parameter as these will result in a really huge buffer since snprintf() takes size_t parameter while ours is ssize_t... Found by Linux Verification Center (linuxtesting.org) with the Svace static analysis tool. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: de: módulo: evita la desreferencia del puntero NULL en vsnprintf() En of_modalias(), podemos pasar los parámetros str y len que provocarían un kernel ups en vsnprintf() ya que solo permite pasar un ptr NULL cuando la longitud también es 0. Además, necesitamos filtrar los valores negativos del parámetro len ya que estos darán como resultado un búfer realmente enorme ya que snprintf() toma el parámetro size_t mientras que el nuestro es ssize_t... Encontrado por el Centro de verificación de Linux (linuxtesting.org) con la herramienta de análisis estático Svace. • https://git.kernel.org/stable/c/e4a449368a2ce6d57a775d0ead27fc07f5a86e5b https://git.kernel.org/stable/c/544561dc56f7e69a053c25e11e6170f48bb97898 https://git.kernel.org/stable/c/a1aa5390cc912934fee76ce80af5f940452fa987 •
CVSS: 5.5EPSS: 0%CPEs: 8EXPL: 0CVE-2024-35877 – x86/mm/pat: fix VM_PAT handling in COW mappings
https://notcve.org/view.php?id=CVE-2024-35877
In the Linux kernel, the following vulnerability has been resolved: x86/mm/pat: fix VM_PAT handling in COW mappings PAT handling won't do the right thing in COW mappings: the first PTE (or, in fact, all PTEs) can be replaced during write faults to point at anon folios. Reliably recovering the correct PFN and cachemode using follow_phys() from PTEs will not work in COW mappings. Using follow_phys(), we might just get the address+protection of the anon folio (which is very wrong), or fail on swap/nonswap entries, failing follow_phys() and triggering a WARN_ON_ONCE() in untrack_pfn() and track_pfn_copy(), not properly calling free_pfn_range(). In free_pfn_range(), we either wouldn't call memtype_free() or would call it with the wrong range, possibly leaking memory. To fix that, let's update follow_phys() to refuse returning anon folios, and fallback to using the stored PFN inside vma->vm_pgoff for COW mappings if we run into that. We will now properly handle untrack_pfn() with COW mappings, where we don't need the cachemode. We'll have to fail fork()->track_pfn_copy() if the first page was replaced by an anon folio, though: we'd have to store the cachemode in the VMA to make this work, likely growing the VMA size. For now, lets keep it simple and let track_pfn_copy() just fail in that case: it would have failed in the past with swap/nonswap entries already, and it would have done the wrong thing with anon folios. Simple reproducer to trigger the WARN_ON_ONCE() in untrack_pfn(): <--- C reproducer ---> #include <stdio.h> #include <sys/mman.h> #include <unistd.h> #include <liburing.h> int main(void) { struct io_uring_params p = {}; int ring_fd; size_t size; char *map; ring_fd = io_uring_setup(1, &p); if (ring_fd < 0) { perror("io_uring_setup"); return 1; } size = p.sq_off.array + p.sq_entries * sizeof(unsigned); /* Map the submission queue ring MAP_PRIVATE */ map = mmap(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, ring_fd, IORING_OFF_SQ_RING); if (map == MAP_FAILED) { perror("mmap"); return 1; } /* We have at least one page. Let's COW it. */ *map = 0; pause(); return 0; } <--- C reproducer ---> On a system with 16 GiB RAM and swap configured: # . • https://git.kernel.org/stable/c/5899329b19100c0b82dc78e9b21ed8b920c9ffb3 https://git.kernel.org/stable/c/f18681daaec9665a15c5e7e0f591aad5d0ac622b https://git.kernel.org/stable/c/09e6bb53217bf388a0d2fd7fb21e74ab9dffc173 https://git.kernel.org/stable/c/c2b2430b48f3c9eaccd2c3d2ad75bb540d4952f4 https://git.kernel.org/stable/c/7cfee26d1950250b14c5cb0a37b142f3fcc6396a https://git.kernel.org/stable/c/97e93367e82752e475a33839a80b33bdbef1209f https://git.kernel.org/stable/c/51b7841f3fe84606ec0bd8da859d22e05e5419ec https://git.kernel.org/stable/c/1341e4b32e1fb1b0acd002ccd56f07bd3 •
CVSS: 5.5EPSS: 0%CPEs: 4EXPL: 0CVE-2024-35875 – x86/coco: Require seeding RNG with RDRAND on CoCo systems
https://notcve.org/view.php?id=CVE-2024-35875
In the Linux kernel, the following vulnerability has been resolved: x86/coco: Require seeding RNG with RDRAND on CoCo systems There are few uses of CoCo that don't rely on working cryptography and hence a working RNG. Unfortunately, the CoCo threat model means that the VM host cannot be trusted and may actively work against guests to extract secrets or manipulate computation. Since a malicious host can modify or observe nearly all inputs to guests, the only remaining source of entropy for CoCo guests is RDRAND. If RDRAND is broken -- due to CPU hardware fault -- the RNG as a whole is meant to gracefully continue on gathering entropy from other sources, but since there aren't other sources on CoCo, this is catastrophic. This is mostly a concern at boot time when initially seeding the RNG, as after that the consequences of a broken RDRAND are much more theoretical. So, try at boot to seed the RNG using 256 bits of RDRAND output. If this fails, panic(). This will also trigger if the system is booted without RDRAND, as RDRAND is essential for a safe CoCo boot. Add this deliberately to be "just a CoCo x86 driver feature" and not part of the RNG itself. • https://git.kernel.org/stable/c/22943e4fe4b3a2dcbadc3d38d5bf840bbdbfe374 https://git.kernel.org/stable/c/453b5f2dec276c1bb4ea078bf8c0da57ee4627e5 https://git.kernel.org/stable/c/08044b08b37528b82f70a87576c692b4e4b7716e https://git.kernel.org/stable/c/99485c4c026f024e7cb82da84c7951dbe3deb584 https://access.redhat.com/security/cve/CVE-2024-35875 https://bugzilla.redhat.com/show_bug.cgi?id=2281727 •
CVSS: -EPSS: 0%CPEs: 5EXPL: 0CVE-2024-35872 – mm/secretmem: fix GUP-fast succeeding on secretmem folios
https://notcve.org/view.php?id=CVE-2024-35872
In the Linux kernel, the following vulnerability has been resolved: mm/secretmem: fix GUP-fast succeeding on secretmem folios folio_is_secretmem() currently relies on secretmem folios being LRU folios, to save some cycles. However, folios might reside in a folio batch without the LRU flag set, or temporarily have their LRU flag cleared. Consequently, the LRU flag is unreliable for this purpose. In particular, this is the case when secretmem_fault() allocates a fresh page and calls filemap_add_folio()->folio_add_lru(). The folio might be added to the per-cpu folio batch and won't get the LRU flag set until the batch was drained using e.g., lru_add_drain(). Consequently, folio_is_secretmem() might not detect secretmem folios and GUP-fast can succeed in grabbing a secretmem folio, crashing the kernel when we would later try reading/writing to the folio, because the folio has been unmapped from the directmap. Fix it by removing that unreliable check. En el kernel de Linux, se resolvió la siguiente vulnerabilidad: mm/secretmem: corrige el éxito rápido de GUP en folios secretmem folio_is_secretmem() actualmente depende de que los folios secretmem sean folios LRU, para guardar algunos ciclos. Sin embargo, las publicaciones pueden residir en un lote de publicaciones sin el indicador LRU establecido o tener su indicador LRU borrado temporalmente. • https://git.kernel.org/stable/c/1507f51255c9ff07d75909a84e7c0d7f3c4b2f49 https://git.kernel.org/stable/c/6564b014af92b677c1f07c44d7f5b595d589cf6e https://git.kernel.org/stable/c/9c2b4b657739ecda38e3b383354a29566955ac48 https://git.kernel.org/stable/c/43fad1d0284de30159661d0badfc3cbaf7e6f8f8 https://git.kernel.org/stable/c/201e4aaf405dfd1308da54448654053004c579b5 https://git.kernel.org/stable/c/65291dcfcf8936e1b23cfd7718fdfde7cfaf7706 •
CVSS: -EPSS: 0%CPEs: 6EXPL: 0CVE-2024-35871 – riscv: process: Fix kernel gp leakage
https://notcve.org/view.php?id=CVE-2024-35871
In the Linux kernel, the following vulnerability has been resolved: riscv: process: Fix kernel gp leakage childregs represents the registers which are active for the new thread in user context. For a kernel thread, childregs->gp is never used since the kernel gp is not touched by switch_to. For a user mode helper, the gp value can be observed in user space after execve or possibly by other means. [From the email thread] The /* Kernel thread */ comment is somewhat inaccurate in that it is also used for user_mode_helper threads, which exec a user process, e.g. /sbin/init or when /proc/sys/kernel/core_pattern is a pipe. Such threads do not have PF_KTHREAD set and are valid targets for ptrace etc. even before they exec. childregs is the *user* context during syscall execution and it is observable from userspace in at least five ways: 1. kernel_execve does not currently clear integer registers, so the starting register state for PID 1 and other user processes started by the kernel has sp = user stack, gp = kernel __global_pointer$, all other integer registers zeroed by the memset in the patch comment. This is a bug in its own right, but I'm unwilling to bet that it is the only way to exploit the issue addressed by this patch. 2. ptrace(PTRACE_GETREGSET): you can PTRACE_ATTACH to a user_mode_helper thread before it execs, but ptrace requires SIGSTOP to be delivered which can only happen at user/kernel boundaries. 3. • https://git.kernel.org/stable/c/7db91e57a0acde126a162ababfb1e0ab190130cb https://git.kernel.org/stable/c/9abc3e6f1116adb7a2d4fbb8ce20c37916976bf5 https://git.kernel.org/stable/c/dff6072124f6df77bfd36951fbd88565746980ef https://git.kernel.org/stable/c/f6583444d7e78dae750798552b65a2519ff3ca84 https://git.kernel.org/stable/c/00effef72c98294edb1efa87ffa0f6cfb61b36a4 https://git.kernel.org/stable/c/d8dcba0691b8e42bddb61aab201e4d918a08e5d9 https://git.kernel.org/stable/c/d14fa1fcf69db9d070e75f1c4425211fa619dfc8 https://lists.debian.org/debian-lts-announce/2024/06/ •