{"id":"CVE-2025-39847","state":"PUBLISHED","title":"ppp: fix memory leak in pad_compress_skb","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nppp: fix memory leak in pad_compress_skb\n\nIf alloc_skb() fails in pad_compress_skb(), it returns NULL without\nreleasing the old skb. The caller does:\n\n    skb = pad_compress_skb(ppp, skb);\n    if (!skb)\n        goto drop;\n\ndrop:\n    kfree_skb(skb);\n\nWhen pad_compress_skb() returns NULL, the reference to the old skb is\nlost and kfree_skb(skb) ends up doing nothing, leading to a memory leak.\n\nAlign pad_compress_skb() semantics with realloc(): only free the old\nskb if allocation and compression succeed.  At the call site, use the\nnew_skb variable so the original skb is not lost when pad_compress_skb()\nfails.","publishedAt":"2025-09-19T15:26:20.648Z","updatedAt":"2026-05-12T12:07:35.941Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"9ca6a040f76c0b149293e430dabab446f3fc8ab7","versionType":"git"},{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"87a35a36742df328d0badf4fbc2e56061c15846c","versionType":"git"},{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"0b21e9cd4559102da798bdcba453b64ecd7be7ee","versionType":"git"},{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"1d8b354eafb8876d8bdb1bef69c7d2438aacfbe8","versionType":"git"},{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"85c1c86a67e09143aa464e9bf09c397816772348","versionType":"git"},{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"631fc8ab5beb9e0ec8651fb9875b9a968e7b4ae4","versionType":"git"},{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"33a5bac5f14772730d2caf632ae97b6c2ee95044","versionType":"git"},{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"4844123fe0b853a4982c02666cb3fd863d701d50","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ppp/ppp_generic.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.15","versionType":"semver"},{"version":"5.4.299","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.243","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.192","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.151","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.105","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.46","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.16.6","status":"unaffected","lessThanOrEqual":"6.16.*","versionType":"semver"},{"version":"6.17","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ppp/ppp_generic.c"]}],"references":["https://git.kernel.org/stable/c/9ca6a040f76c0b149293e430dabab446f3fc8ab7","https://git.kernel.org/stable/c/87a35a36742df328d0badf4fbc2e56061c15846c","https://git.kernel.org/stable/c/0b21e9cd4559102da798bdcba453b64ecd7be7ee","https://git.kernel.org/stable/c/1d8b354eafb8876d8bdb1bef69c7d2438aacfbe8","https://git.kernel.org/stable/c/85c1c86a67e09143aa464e9bf09c397816772348","https://git.kernel.org/stable/c/631fc8ab5beb9e0ec8651fb9875b9a968e7b4ae4","https://git.kernel.org/stable/c/33a5bac5f14772730d2caf632ae97b6c2ee95044","https://git.kernel.org/stable/c/4844123fe0b853a4982c02666cb3fd863d701d50","https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html","https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html","https://cert-portal.siemens.com/productcert/html/ssa-032379.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/39xxx/CVE-2025-39847.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-39847","state":"PUBLISHED","datePublished":"2025-09-19T15:26:20.648Z","dateUpdated":"2026-05-12T12:07:35.941Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T07:20:57.141Z"},"containers":{"cna":{"title":"ppp: fix memory leak in pad_compress_skb","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nppp: fix memory leak in pad_compress_skb\n\nIf alloc_skb() fails in pad_compress_skb(), it returns NULL without\nreleasing the old skb. The caller does:\n\n    skb = pad_compress_skb(ppp, skb);\n    if (!skb)\n        goto drop;\n\ndrop:\n    kfree_skb(skb);\n\nWhen pad_compress_skb() returns NULL, the reference to the old skb is\nlost and kfree_skb(skb) ends up doing nothing, leading to a memory leak.\n\nAlign pad_compress_skb() semantics with realloc(): only free the old\nskb if allocation and compression succeed.  At the call site, use the\nnew_skb variable so the original skb is not lost when pad_compress_skb()\nfails."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"9ca6a040f76c0b149293e430dabab446f3fc8ab7","versionType":"git"},{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"87a35a36742df328d0badf4fbc2e56061c15846c","versionType":"git"},{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"0b21e9cd4559102da798bdcba453b64ecd7be7ee","versionType":"git"},{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"1d8b354eafb8876d8bdb1bef69c7d2438aacfbe8","versionType":"git"},{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"85c1c86a67e09143aa464e9bf09c397816772348","versionType":"git"},{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"631fc8ab5beb9e0ec8651fb9875b9a968e7b4ae4","versionType":"git"},{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"33a5bac5f14772730d2caf632ae97b6c2ee95044","versionType":"git"},{"version":"b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c","status":"affected","lessThan":"4844123fe0b853a4982c02666cb3fd863d701d50","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ppp/ppp_generic.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.15","versionType":"semver"},{"version":"5.4.299","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.243","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.192","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.151","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.105","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.46","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.16.6","status":"unaffected","lessThanOrEqual":"6.16.*","versionType":"semver"},{"version":"6.17","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ppp/ppp_generic.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/9ca6a040f76c0b149293e430dabab446f3fc8ab7"},{"url":"https://git.kernel.org/stable/c/87a35a36742df328d0badf4fbc2e56061c15846c"},{"url":"https://git.kernel.org/stable/c/0b21e9cd4559102da798bdcba453b64ecd7be7ee"},{"url":"https://git.kernel.org/stable/c/1d8b354eafb8876d8bdb1bef69c7d2438aacfbe8"},{"url":"https://git.kernel.org/stable/c/85c1c86a67e09143aa464e9bf09c397816772348"},{"url":"https://git.kernel.org/stable/c/631fc8ab5beb9e0ec8651fb9875b9a968e7b4ae4"},{"url":"https://git.kernel.org/stable/c/33a5bac5f14772730d2caf632ae97b6c2ee95044"},{"url":"https://git.kernel.org/stable/c/4844123fe0b853a4982c02666cb3fd863d701d50"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T21:37:35.647Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.15","versionEndExcluding":"5.4.299"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.15","versionEndExcluding":"5.10.243"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.15","versionEndExcluding":"5.15.192"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.15","versionEndExcluding":"6.1.151"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.15","versionEndExcluding":"6.6.105"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.15","versionEndExcluding":"6.12.46"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.15","versionEndExcluding":"6.16.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.15","versionEndExcluding":"6.17"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE 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