جزئیات آسیب‌پذیری

In the Linux kernel, the following vulnerability has been resolved: block: don't overwrite bip_vcnt in bio_integrity_copy_user() bio_integrity_add_page() already sets bip_vcnt to 1 for the bounce segment. Overwriting it with nr_vecs breaks bip_vcnt <= bip_max_vcnt on WRITE (bip_max_vcnt is 1), so the gap-merge checks in block/blk.h read past the bip_vec[] flex array. On READ the read is in bounds but lands on a saved user bvec instead of the bounce. The line was added for split propagation, but bio_integrity_clone() doesn't copy bip_vcnt and BIP_CLONE_FLAGS excludes BIP_COPY_USER.

• https://git.kernel.org/stable/c/d18160c9525c63c203656fefd847e94b538cd4a4
• https://git.kernel.org/stable/c/0d48654af4d1390c888389206cc13b51b82c30e6
• https://git.kernel.org/stable/c/066be1439593a381b1a29663becfcfe0c92363e7
• https://git.kernel.org/stable/c/637ad3a56a3b889527d1dacea6fea2a8bd648140