CVE-2026-90077net: fix a resource leak in copy_net_ns() error handling path

Official description

In the Linux kernel, the following vulnerability has been resolved: net: fix a resource leak in copy_net_ns() error handling path Currently, preinit_net() does two things: (1) call ns_common_init() which might fail (2) initialize resources which does not fail However, preinit_net() is returning early when (1) fails, and copy_net_ns() is jumping to the dec_ucounts: label. As a result, resources allocated by net_alloc() are leaking. We need to call key_remove_domain() and net_passive_dec() in order to release resources allocated by net_alloc(). We cannot simply jump to the put_userns: label when preinit_net() failed, for (2) is not yet done. But we can reorder (1) and (2), for there is no dependency between (1) and (2). Therefore, this patch decouples (1) from preinit_net() and changes preinit_net() back to a void function, and calls ns_common_init() after preinit_net() succeeded. Then, we can jump to immediately after ns_common_free() of the put_userns: label.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/76c847e80d2b6be047707d58e8e05eedbe2593ad
• https://git.kernel.org/stable/c/e69bde4eb566aea8fa97cbb93e0bab608964f1a5
• https://git.kernel.org/stable/c/3220b62fbb8a55feebd2a826d5ead0f49f09ed5a