Описание
In the Linux kernel, the following vulnerability has been resolved:
NFSv4.2: Rework scratch handling for READ_PLUS (again)
I found that the read code might send multiple requests using the same nfs_pgio_header, but nfs4_proc_read_setup() is only called once. This is how we ended up occasionally double-freeing the scratch buffer, but also means we set a NULL pointer but non-zero length to the xdr scratch buffer. This results in an oops the first time decoding needs to copy something to scratch, which frequently happens when decoding READ_PLUS hole segments.
I fix this by moving scratch handling into the pageio read code. I provide a function to allocate scratch space for decoding read replies, and free the scratch buffer when the nfs_pgio_header is freed.
Ссылки
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Уязвимые конфигурации
Одно из
EPSS
9.8 Critical
CVSS3
5.5 Medium
CVSS3
Дефекты
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: NFSv4.2: Rework scratch handling for READ_PLUS (again) I found that the read code might send multiple requests using the same nfs_pgio_header, but nfs4_proc_read_setup() is only called once. This is how we ended up occasionally double-freeing the scratch buffer, but also means we set a NULL pointer but non-zero length to the xdr scratch buffer. This results in an oops the first time decoding needs to copy something to scratch, which frequently happens when decoding READ_PLUS hole segments. I fix this by moving scratch handling into the pageio read code. I provide a function to allocate scratch space for decoding read replies, and free the scratch buffer when the nfs_pgio_header is freed.
In the Linux kernel, the following vulnerability has been resolved: NFSv4.2: Rework scratch handling for READ_PLUS (again) I found that the read code might send multiple requests using the same nfs_pgio_header, but nfs4_proc_read_setup() is only called once. This is how we ended up occasionally double-freeing the scratch buffer, but also means we set a NULL pointer but non-zero length to the xdr scratch buffer. This results in an oops the first time decoding needs to copy something to scratch, which frequently happens when decoding READ_PLUS hole segments. I fix this by moving scratch handling into the pageio read code. I provide a function to allocate scratch space for decoding read replies, and free the scratch buffer when the nfs_pgio_header is freed.
In the Linux kernel, the following vulnerability has been resolved: N ...
In the Linux kernel, the following vulnerability has been resolved: NFSv4.2: Rework scratch handling for READ_PLUS (again) I found that the read code might send multiple requests using the same nfs_pgio_header, but nfs4_proc_read_setup() is only called once. This is how we ended up occasionally double-freeing the scratch buffer, but also means we set a NULL pointer but non-zero length to the xdr scratch buffer. This results in an oops the first time decoding needs to copy something to scratch, which frequently happens when decoding READ_PLUS hole segments. I fix this by moving scratch handling into the pageio read code. I provide a function to allocate scratch space for decoding read replies, and free the scratch buffer when the nfs_pgio_header is freed.
Уязвимость функций nfs4_read_done(), nfs42_read_plus_support() модуля fs/nfs/nfs4proc.c драйвера файловой системы NFS ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании
EPSS
9.8 Critical
CVSS3
5.5 Medium
CVSS3