CVE-2025-39847

ppp: fix memory leak in pad_compress_skb

State: Published
Severity: Not scored
Published: Sep 19, 2025
Updated: May 12, 2026
Reserved: Apr 16, 2025

Read the record on cve.org

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.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 9ca6a040f76c0b149293e430dabab446f3fc8ab7Affected b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 87a35a36742df328d0badf4fbc2e56061c15846cAffected b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 0b21e9cd4559102da798bdcba453b64ecd7be7eeAffected b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 1d8b354eafb8876d8bdb1bef69c7d2438aacfbe8Affected b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 85c1c86a67e09143aa464e9bf09c397816772348Affected b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 631fc8ab5beb9e0ec8651fb9875b9a968e7b4ae4Affected b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 33a5bac5f14772730d2caf632ae97b6c2ee95044Affected b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 4844123fe0b853a4982c02666cb3fd863d701d50Affected
LinuxLinux	2.6.15Affected before 2.6.15Not affected 5.4.299 through 5.4.Not affected 5.10.243 through 5.10.Not affected 5.15.192 through 5.15.Not affected 6.1.151 through 6.1.Not affected 6.6.105 through 6.6.Not affected 6.12.46 through 6.12.Not affected 6.16.6 through 6.16.*Not affected 6.17 and laterNot affected

Product

Versions

LinuxLinux

b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 9ca6a040f76c0b149293e430dabab446f3fc8ab7Affected
b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 87a35a36742df328d0badf4fbc2e56061c15846cAffected
b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 0b21e9cd4559102da798bdcba453b64ecd7be7eeAffected
b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 1d8b354eafb8876d8bdb1bef69c7d2438aacfbe8Affected
b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 85c1c86a67e09143aa464e9bf09c397816772348Affected
b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 631fc8ab5beb9e0ec8651fb9875b9a968e7b4ae4Affected
b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 33a5bac5f14772730d2caf632ae97b6c2ee95044Affected
b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c to before 4844123fe0b853a4982c02666cb3fd863d701d50Affected

LinuxLinux

2.6.15Affected
before 2.6.15Not affected
5.4.299 through 5.4.*Not affected
5.10.243 through 5.10.*Not affected
5.15.192 through 5.15.*Not affected
6.1.151 through 6.1.*Not affected
6.6.105 through 6.6.*Not affected
6.12.46 through 6.12.*Not affected
6.16.6 through 6.16.*Not affected
6.17 and laterNot affected

References

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