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CVE-2026-31649: Linux, грешка в паметта

9.8

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 по мрежата, без особени условия, без вход и без действие от потребителя.

CVE радар: още уязвимости от този вид

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

Описание

Оригинално описание

In the Linux kernel, the following vulnerability has been resolved: net: stmmac: fix integer underflow in chain mode The jumbo_frm() chain-mode implementation unconditionally computes len = nopaged_len - bmax; where nopaged_len = skb_headlen(skb) (linear bytes only) and bmax is BUF_SIZE_8KiB or BUF_SIZE_2KiB. However, the caller stmmac_xmit() decides to invoke jumbo_frm() based on skb->len (total length including page fragments): is_jumbo = stmmac_is_jumbo_frm(priv, skb->len, enh_desc); When a packet has a small linear portion (nopaged_len <= bmax) but a large total length due to page fragments (skb->len > bmax), the subtraction wraps as an unsigned integer, producing a huge len value (~0xFFFFxxxx). This causes the while (len != 0) loop to execute hundreds of thousands of iterations, passing skb->data + bmax * i pointers far beyond the skb buffer to dma_map_single(). On IOMMU-less SoCs (the typical deployment for stmmac), this maps arbitrary kernel memory to the DMA engine, constituting a kernel memory disclosure and potential memory corruption from hardware. Fix this by introducing a buf_len local variable clamped to min(nopaged_len, bmax). Computing len = nopaged_len - buf_len is then always safe: it is zero when the linear portion fits within a single descriptor, causing the while (len != 0) loop to be skipped naturally, and the fragment loop in stmmac_xmit() handles page fragments afterward.

Засегнати продукти

  • Linux Linux: 286a837217204b1ef105e3a554d0757e4fdfaac1 преди 513e06735f5be575b409d195822195348b164e48; 286a837217204b1ef105e3a554d0757e4fdfaac1 преди 275bdf762e82082f064e60a92448fa2ac43cf95b; 286a837217204b1ef105e3a554d0757e4fdfaac1 преди a2b68a9a476b9544ff31f1fbcd5d80867a8a5e2f; 286a837217204b1ef105e3a554d0757e4fdfaac1 преди b7b8012193fd98236d7ae05d4b553f010a77b2ef; 286a837217204b1ef105e3a554d0757e4fdfaac1 преди 2c91b39912278d0878f9ba60ba04d2518b18a08d; 286a837217204b1ef105e3a554d0757e4fdfaac1 преди 6fca757c20396dc2e604dcc61922264e9e3dc803; 286a837217204b1ef105e3a554d0757e4fdfaac1 преди 10d12b9240ebf96c785f0e2e4228318cd5f3a3eb; 286a837217204b1ef105e3a554d0757e4fdfaac1 преди 51f4e090b9f87b40c21b6daadb5c06e6c0a07b67
  • Linux Linux: 3.2; преди 3.2; 5.10.253 до 5.10.*; 5.15.203 до 5.15.*; 6.1.169 до 6.1.*; 6.6.135 до 6.6.*; 6.12.82 до 6.12.*; 6.18.23 до 6.18.*; 6.19.13 до 6.19.*; от 7.0 нататък
  • Siemens: още 3 продукта, добавени от Siemens

    SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP, SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Вид слабост

История

  • 24 април 2026 Публикувано

Други уязвимости в Linux Linux

Първоизточници

CVE-2026-31649: Linux, грешка в паметта | freedomonline.bg