Overview
About vulnerability
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.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- kernel @ 4.18.0 (+15 more)
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.