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Vulnerability · Published Sep 19, 2025 · Assigned by Linux

CVE-2025-39847ppp: fix memory leak in pad_compress_skb

Medium 5.5

In plain English

A medium-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.2%top 94.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: ppp: fix memory leak in pad_compress_skb If alloc_skb() fails in pad_compress_skb(), it returns NULL without releasing the old skb. The caller does: skb = pad_compress_skb(ppp, skb); if (!skb) goto drop; drop: kfree_skb(skb); When pad_compress_skb() returns NULL, the reference to the old skb is lost and kfree_skb(skb) ends up doing nothing, leading to a memory leak. Align pad_compress_skb() semantics with realloc(): only free the old skb if allocation and compression succeed. At the call site, use the new_skb variable so the original skb is not lost when pad_compress_skb() fails.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.153-1DEBIAN-CVE-2025-39847
Debian:13linux6.12.48-1DEBIAN-CVE-2025-39847
Debian:14linux6.16.6-1DEBIAN-CVE-2025-39847
Ubuntu:22.04:LTSlinux5.15.0-163.173UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux6.8.0-106.106UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-aws5.15.0-1097.104UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-aws6.8.0-1050.53UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1050.53~22.04.1UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-azure5.15.0-1101.110UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-azure6.8.0-1051.57UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1051.57~22.04.1UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1102.111.1UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1058.65UBUNTU-CVE-2025-39847
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1058.65~22.04.1UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-gcp5.15.0-1097.106UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-gcp6.8.0-1052.55UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1052.55~22.04.1UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-gke5.15.0-1093.99UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-gke6.8.0-1048.53UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1080.88UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1035.38UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-106.106~22.04.1UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-ibm5.15.0-1091.94UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-ibm6.8.0-1049.49UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1049.49~22.04.1UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-intelno fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1092.98UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-kvm5.15.0-1089.94UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-163.173UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-106.106.1UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-106.106.1~22.04.1UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1092.93UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1049.52UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1049.52~22.04.1UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1049.52.1UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1049.49UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1020.20UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1038.38UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-oracle5.15.0-1094.100UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-oracle6.8.0-1047.48UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1047.48~22.04.1UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-raspi5.15.0-1091.94UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-raspi6.8.0-1050.54UBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-106.106~22.04.1UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2025-39847
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1028.29UBUNTU-CVE-2025-39847
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1061.65UBUNTU-CVE-2025-39847

Affected products (as reported)

VendorProductVersions
Linux Linux b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c – before 9ca6a040f76c0b149293e430dabab446f3fc8ab7b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c – before 87a35a36742df328d0badf4fbc2e56061c15846cb3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c – before 0b21e9cd4559102da798bdcba453b64ecd7be7eeb3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c – before 1d8b354eafb8876d8bdb1bef69c7d2438aacfbe8b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c – before 85c1c86a67e09143aa464e9bf09c397816772348b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c – before 631fc8ab5beb9e0ec8651fb9875b9a968e7b4ae4b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c – before 33a5bac5f14772730d2caf632ae97b6c2ee95044b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c – before 4844123fe0b853a4982c02666cb3fd863d701d50
Linux Linux 2.6.15

References