CVSS 7.1 · High EPSS 0,16%
Kerentanan Out-of-bounds Read pada linux kernel. Skor CVSS 3.1 7.1 (High) menurut NVD.
In the Linux kernel, the following vulnerability has been resolved: dm-verity-fec: fix reading parity bytes split across blocks (take 3) fec_decode_bufs() assumes that the parity bytes of the first RS codeword it decodes are never split across parity blocks. This assumption is false. Consider v->fec->block_size == 4096 && v->fec->roots == 17 && fio->nbufs == 1, for example. In that case, each call to fec_decode_bufs() consumes v->fec->roots * (fio->nbufs << DM_VERITY_FEC_BUF_RS_BITS) = 272 parity bytes. Considering that the parity data for each message block starts on a block boundary, the byte alignment in the parity data will iterate through 272*i mod 4096 until the 3 parity blocks have been consumed. On the 16th call (i=15), the alignment will be 4080 bytes into the first block. Only 16 bytes remain in that block, but 17 parity bytes will be needed. The code reads out-of-bounds from the parity block buffer. Fortunately this doesn't normally happen, since it can occur only for certain non-default values of fec_roots *and* when the maximum number of buffers couldn't be allocated due to low memory. For example with block_size=4096 only the following cases are affected: fec_roots=17: nbufs in [1, 3, 5, 15] fec_roots=19: nbufs in [1, 229] fec_roots=21: nbufs in [1, 3, 5, 13, 15, 39, 65, 195] fec_roots=23: nbufs in [1, 89] Regardless, fix it by refactoring how the parity blocks are read.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
· uraikan di kalkulator | Vendor | Produk | Versi terdampak |
|---|---|---|
| linux | linux kernel | Versi 6.1.125 hingga sebelum 6.2 |
| linux | linux kernel | Versi 6.6.72 hingga sebelum 6.7 |
| linux | linux kernel | Versi 6.12.10 hingga sebelum 6.13 |
| linux | linux kernel | Versi 6.13.1 hingga sebelum 7.0.7 |
| linux | linux kernel | Versi 6.13 |
| linux | linux kernel | Versi 6.13 rc7 |