In the Linux kernel, the following vulnerability has been resolved: cachefiles: Set object to close if ondemand_id < 0 in copen If copen is maliciously called in the user mode, it may delete the request corresponding to the random id. And the request may have not been read yet. Note that when the object is set to reopen, the open request will be done with the still reopen state in above case. As a result, the request corresponding to this object is always skipped in select_req function, so the read request is never completed and blocks other process. Fix this issue by simply set object to close if its id < 0 in copen.
https://git.kernel.org/stable/c/c32ee78fbc670e6f90989a45d340748e34cad333
https://git.kernel.org/stable/c/703bea37d13e4ccdafd17ae7c4cb583752ba7663
https://git.kernel.org/stable/c/4f8703fb3482f92edcfd31661857b16fec89c2c0
https://git.kernel.org/stable/c/0845c553db11c84ff53fccd59da11b6d6ece4a60