CVE-2021-47107
Vulnerability from cvelistv5
Published
2024-03-04 18:15
Modified
2024-12-19 07:35
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: NFSD: Fix READDIR buffer overflow If a client sends a READDIR count argument that is too small (say, zero), then the buffer size calculation in the new init_dirlist helper functions results in an underflow, allowing the XDR stream functions to write beyond the actual buffer. This calculation has always been suspect. NFSD has never sanity- checked the READDIR count argument, but the old entry encoders managed the problem correctly. With the commits below, entry encoding changed, exposing the underflow to the pointer arithmetic in xdr_reserve_space(). Modern NFS clients attempt to retrieve as much data as possible for each READDIR request. Also, we have no unit tests that exercise the behavior of READDIR at the lower bound of @count values. Thus this case was missed during testing.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/53b1119a6e5028b125f431a0116ba73510d82a72
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9e291a6a28d32545ed2fd959a8165144d1724df1
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/eabc0aab98e5218ceecd82069b0d6fdfff5ee885
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/53b1119a6e5028b125f431a0116ba73510d82a72
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/9e291a6a28d32545ed2fd959a8165144d1724df1
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/eabc0aab98e5218ceecd82069b0d6fdfff5ee885
Impacted products
Vendor Product Version
Linux Linux Version: 5.13
Show details on NVD website

To clipboard 

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