Description
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 products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
9b9960a0ca4773e21c4b153ed355583946346b25 to < 3a7fd224df0fbb42167eb1b77be45d72fe0b1098affected9b9960a0ca4773e21c4b153ed355583946346b25 to < 29e4478e2ed5a227e8f0c33cacb91bf227cedd47affected9b9960a0ca4773e21c4b153ed355583946346b25 to < 65a72b721943618eeb3a41c8b36e915591f3f83faffected9b9960a0ca4773e21c4b153ed355583946346b25 to < bee826c00ac900473f91306f1f3e5a5a81fd4a74affected9b9960a0ca4773e21c4b153ed355583946346b25 to < e7d9d23ecd9172f05b09bb678ff22db8e361c428affected9b9960a0ca4773e21c4b153ed355583946346b25 to < 0380129b1373c437eb35401a174671c8888f4b80affected9b9960a0ca4773e21c4b153ed355583946346b25 to < c81cef6a805dec266c10fc4f83c93d6fcf1a2b43affected9b9960a0ca4773e21c4b153ed355583946346b25 to < f9868174af49d207fbaf0c5e055d088a983684afaffected
Linux Linux
Default version status: affected
4.8affected0 to < 4.8unaffected5.10.270 to ≤ 5.10.*unaffected5.15.221 to ≤ 5.15.*unaffected6.1.188 to ≤ 6.1.*unaffected6.6.157 to ≤ 6.6.*unaffected6.12.109 to ≤ 6.12.*unaffected6.18.50 to ≤ 6.18.*unaffected7.2.4 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
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 ↗