Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix XDR length calculation in nfsd4_ff_encode_layoutget The XDR buffer size calculation in nfsd4_ff_encode_layoutget() has multiple errors that can result in either an out-of-bounds write or leaking uninitialized kernel memory to the client: - fh_len doesn't account for XDR padding on the file handle data - uid and gid lengths use "8 + len" but xdr_encode_opaque() actually writes "4 + xdr_align_size(len)" bytes - ds_len omits the flags and stats_collect_hint fields (8 bytes), while len's header constant overestimates by 8 bytes -- these partially cancel but leave a net mismatch The worst case occurs with short strings (e.g. uid=0, gid=0 with an odd-sized file handle), where the function writes up to 5 bytes past the reserved XDR buffer. Conversely, when string lengths happen to be 4-byte aligned, the reservation is too large and stale buffer content is sent to the client. Fix this by breaking out every encoded field explicitly in the ds_len calculation, using xdr_align_size() for all variable-length opaque fields, and correcting the header constants.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 9b9960a0ca4773e21c4b153ed355583946346b25 before 3a7fd224df0fbb42167eb1b77be45d72fe0b1098; affected 9b9960a0ca4773e21c4b153ed355583946346b25 before 29e4478e2ed5a227e8f0c33cacb91bf227cedd47; affected 9b9960a0ca4773e21c4b153ed355583946346b25 before 65a72b721943618eeb3a41c8b36e915591f3f83f; affected 9b9960a0ca4773e21c4b153ed355583946346b25 before bee826c00ac900473f91306f1f3e5a5a81fd4a74; affected 9b9960a0ca4773e21c4b153ed355583946346b25 before e7d9d23ecd9172f05b09bb678ff22db8e361c428; affected 9b9960a0ca4773e21c4b153ed355583946346b25 before 0380129b1373c437eb35401a174671c8888f4b80; affected 9b9960a0ca4773e21c4b153ed355583946346b25 before c81cef6a805dec266c10fc4f83c93d6fcf1a2b43; affected 9b9960a0ca4773e21c4b153ed355583946346b25 before f9868174af49d207fbaf0c5e055d088a983684af |
| Linux / Linux | affected 4.8; unaffected 0 before 4.8; unaffected 5.10.270 through 5.10.*; unaffected 5.15.221 through 5.15.*; unaffected 6.1.188 through 6.1.*; unaffected 6.6.157 through 6.6.*; unaffected 6.12.109 through 6.12.*; unaffected 6.18.50 through 6.18.*; unaffected 7.2.4 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/3a7fd224df0fbb42167eb1b77be45d72fe0b1098
- https://git.kernel.org/stable/c/29e4478e2ed5a227e8f0c33cacb91bf227cedd47
- https://git.kernel.org/stable/c/65a72b721943618eeb3a41c8b36e915591f3f83f
- https://git.kernel.org/stable/c/bee826c00ac900473f91306f1f3e5a5a81fd4a74
- https://git.kernel.org/stable/c/e7d9d23ecd9172f05b09bb678ff22db8e361c428
- https://git.kernel.org/stable/c/0380129b1373c437eb35401a174671c8888f4b80
- https://git.kernel.org/stable/c/c81cef6a805dec266c10fc4f83c93d6fcf1a2b43
- https://git.kernel.org/stable/c/f9868174af49d207fbaf0c5e055d088a983684af