CVE-2026-23230
Description
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.
How to fix
- linux linux_kernel6.1.164, 6.6.125, 6.12.72, 6.18.11, 6.19.1 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| linux linux_kernel | 6.1 ≤ v < 6.1.164, 6.2 ≤ v < 6.6.125, 6.7 ≤ v < 6.12.72, 6.13 ≤ v < 6.18.11, 6.19 ≤ v < 6.19.1 | 6.1.164, 6.6.125, 6.12.72, 6.18.11, 6.19.1 |
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