CVE-2024-40983

In the Linux kernel, the following vulnerability has been resolved:

tipc: force a dst refcount before doing decryption

As it says in commit 3bc07321ccc2 ("xfrm: Force a dst refcount before entering the xfrm type handlers"):

"Crypto requests might return asynchronous. In this case we leave the rcu protected region, so force a refcount on the skb's destination entry before we enter the xfrm type input/output handlers."

On TIPC decryption path it has the same problem, and skbdstforce() should be called before doing decryption to avoid a possible crash.

Shuang reported this issue when this warning is triggered:

[] WARNING: include/net/dst.h:337 tipcskrcv+0x1055/0x1ea0 [tipc] [] Kdump: loaded Tainted: G W --------- - - 4.18.0-496.el8.x8664+debug [] Workqueue: crypto cryptdqueueworker [] RIP: 0010:tipcskrcv+0x1055/0x1ea0 [tipc] [] Call Trace: [] tipcskmcastrcv+0x548/0xea0 [tipc] [] tipcrcv+0xcf5/0x1060 [tipc] [] tipcaeaddecryptdone+0x215/0x2e0 [tipc] [] cryptdaeadcrypt+0xdb/0x190 [] cryptdqueueworker+0xed/0x190 [] processonework+0x93d/0x17e0