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CVE-2026-63806: Linux, отказ на услуга

7.1

CVSS 3.1

Няма данни

Вероятност да бъде експлоатирана в следващите 30 дни (EPSS)

Няма потвърждение

Атакува се

Няма данни

Време до експлоатация

Атакува се локално, без особени условия, без вход и без действие от потребителя.

CVE радар: още уязвимости от този вид

  • Експлоатация: няма данни за експлоатация
  • Атаката не може да се автоматизира

Описание

Оригинално описание

In the Linux kernel, the following vulnerability has been resolved: KVM: Replace guest-triggerable BUG_ON() in ioeventfd datamatch with get_unaligned() Drop a BUG_ON() that has been reachable since it was first added, way back in 2009, and instead use get_unaligned() to perform potentially-unaligned accesses. For a given store, KVM x86's emulator tracks the entire value in the destination operand, x86_emulate_ctxt.dst. If the destination is memory, and the target splits multiple pages and/or is emulated MMIO, then KVM handles each fragment independently. E.g. on a page split starting at page offset 0xffc, KVM writes 4 bytes to the first page, then the remaining bytes to the second page, using ctxt->dst as the source for both (with appropriate offsets). If the destination splits a page *and* hits emulated MMIO on the second page, then KVM will complete the write to the first page, then emulate the MMIO access to the second page. If there is a datamatch-enabled ioeventfd at offset 0 of the second page, then KVM will process the remainder of the store as a potential ioeventfd signal. Putting it all together, if the guest emits a store that splits a page starting at page offset N, and the second page has a datamatch-enabled ioeventfd at offset 0, then KVM will check for datamatch using &dst.valptr[N] as the source. Due to dst (and thus dst.valptr) being 32-byte aligned, if N is not aligned to @len, the BUG_ON() fires. E.g. with a 16-byte store at page offset 0xffc, to an ioeventfd of len 8, all initial checks in ioeventfd_in_range() will succeed, and the BUG_ON() fires due to @val being 4-byte aligned, but not 8-byte aligned. ------------[ cut here ]------------ kernel BUG at arch/x86/kvm/../../../virt/kvm/eventfd.c:783! Oops: invalid opcode: 0000 [#1] SMP CPU: 0 UID: 1000 PID: 615 Comm: repro Not tainted 7.1.0-rc2-ff238429d1ea #365 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:ioeventfd_write+0x6c/0x7

Засегнати продукти

  • Linux Linux: d34e6b175e61821026893ec5298cc8e7558df43a преди 2426c15c1395b7d5ccf1e5025ca898af7f3decb6; d34e6b175e61821026893ec5298cc8e7558df43a преди 4186c850789906b875a1d263377a4d37c078e317; d34e6b175e61821026893ec5298cc8e7558df43a преди 36ff44fb3d89960391e013fb9d91e23dbc48be47; d34e6b175e61821026893ec5298cc8e7558df43a преди 92fc631b69deb1c7d56aec2663003600799dcd75; d34e6b175e61821026893ec5298cc8e7558df43a преди bf89e3738480d33cd515b4a18900e8443d40cd2e; d34e6b175e61821026893ec5298cc8e7558df43a преди 5da9b1a87ec7cc3489c27016313524769f12d9e0; d34e6b175e61821026893ec5298cc8e7558df43a преди 5c87b47374682f69686068ad0a7779365a527b1c; d34e6b175e61821026893ec5298cc8e7558df43a преди f1edbed787ba67988ed34e0132ca128b052b6ce8
  • Linux Linux: 2.6.32; преди 2.6.32; 5.10.261 до 5.10.*; 5.15.212 до 5.15.*; 6.1.178 до 6.1.*; 6.6.145 до 6.6.*; 6.12.95 до 6.12.*; 6.18.38 до 6.18.*; 7.1.3 до 7.1.*; от 7.2 нататък

Вид слабост

История

  • 19 юли 2026 Публикувано

Други уязвимости в Linux Linux

Първоизточници

CVE-2026-63806: Linux, отказ на услуга | freedomonline.bg