جزئیات آسیب‌پذیری

In the Linux kernel, the following vulnerability has been resolved: smb: client: split cached_fid bitfields to avoid shared-byte RMW races is_open, has_lease and on_list are stored in the same bitfield byte in struct cached_fid but are updated in different code paths that may run concurrently. Bitfield assignments generate byte read–modify–write operations (e.g. `orb $mask, addr` on x86_64), so updating one flag can restore stale values of the others. A possible interleaving is: CPU1: load old byte (has_lease=1, on_list=1) CPU2: clear both flags (store 0) CPU1: RMW store (old | IS_OPEN) -> reintroduces cleared bits To avoid this class of races, convert these flags to separate bool fields.

• https://git.kernel.org/stable/c/569fecc56bfe4df66f05734d67daef887746656b
• https://git.kernel.org/stable/c/4386f6af8aaedd0c5ad6f659b40cadcc8f423828
• https://git.kernel.org/stable/c/3eaa22d688311c708b73f3c68bc6d0c8e3f0f77a
• https://git.kernel.org/stable/c/c4b9edd55987384a1f201d3d07ff71e448d79c1b
• https://git.kernel.org/stable/c/4cfa4c37dcbcfd70866e856200ed8a2894cac578
• https://git.kernel.org/stable/c/ec306600d5ba7148c9dbf8f5a8f1f5c1a044a241
• https://cert-portal.siemens.com/productcert/html/ssa-253495.html