NFSv4.0: Fix a use-after-free problem in the asynchronous open()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: NFSv4.0: Fix a use-after-free problem in the asynchronous open() Yang Erkun reports that when two threads are opening files at the same time, and are forced to abort before a reply is seen, then the call to nfs_release_seqid() in nfs4_opendata_free() can result in a use-after-free of the pointer to the defunct rpc task of the other thread. The fix is to ensure that if the RPC call is aborted before the call to nfs_wait_on_sequence() is complete, then we must call nfs_release_seqid() in nfs4_open_release() before the rpc_task is freed.

References

• https://git.kernel.org/stable/c/1cfae9575296f5040cdc84b0730e79078c081d2d
• https://git.kernel.org/stable/c/7bf6bf130af8ee7d93a99c28a7512df3017ec759
• https://git.kernel.org/stable/c/5237a297ffd374a1c4157a53543b7a69d7bbbc03
• https://git.kernel.org/stable/c/2ab9639f16b05d948066a6c4cf19a0fdc61046ff
• https://git.kernel.org/stable/c/ba6e6c04f60fe52d91520ac4d749d372d4c74521
• https://git.kernel.org/stable/c/229a30ed42bb87bcb044c5523fabd9e4f0e75648
• https://git.kernel.org/stable/c/e2277a1d9d5cd0d625a4fd7c04fce2b53e66df77
• https://git.kernel.org/stable/c/b56ae8e715557b4fc227c9381d2e681ffafe7b15
• https://git.kernel.org/stable/c/2fdb05dc0931250574f0cb0ebeb5ed8e20f4a889