Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: arm64: io: Reject non-user protection in ioremap_prot() Mapping a stack-top page via /dev/mem with PROT_NONE and then reading that process's /proc/<pid>/cmdline triggers a spurious WARN in ioremap_prot() through generic_access_phys(): WARNING: ./arch/arm64/include/asm/io.h:275 at generic_access_phys Call trace: generic_access_phys+0x1c8/0x228 (P) __access_remote_vm+0x2b4/0x398 access_remote_vm+0x14/0x30 get_mm_cmdline+0xf8/0x2a0 proc_pid_cmdline_read+0x68/0x120 generic_access_phys() passes the protection derived from the user PTE to ioremap_prot(). On arm64, a PROT_NONE mapping is represented by a present-invalid PTE, so pte_present() still returns true and the protection reaches ioremap_prot(). A PROT_NONE mapping does not have PTE_USER, causing the existing WARN_ON_ONCE() in ioremap_prot() to fire even though this is a valid user mapping. Execute-only mappings have the same issue and must not be readable through this path either. ioremap_prot() should therefore reject protection values without PTE_USER without warning. This makes the access fail cleanly for PROT_NONE and execute-only mappings while retaining the existing user-protection contract.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 64858b76ec67c5fc40fef8ec1841fecb78c1ebde before fddc90d4af4550af410f52d11bbf6b5f36443838; affected eeecafce5afffb4da703666ebefbd4d6e2a5abf6 before 0b04af3d88bb7fc69b2d92457890608860e42365; affected 3d64dcc0799c2d6921ba027716b7be721eb19fa8 before b17aa4955e3a694c663ebe99626e4c76ca4f7cfb; affected 8f098037139b294050053123ab2bc0f819d08932 before 9b583795feb51f8d50203228d001760d1344ef01; affected 8f098037139b294050053123ab2bc0f819d08932 before bb756b11ad63832ebee58caf9e8f9381eaecff9f; affected d1ad8fe7f72d73e1617bac79f2ec7a3bedf47e2a; affected 6.6.143 before 6.6.158; affected 6.12.93 before 6.12.112; affected 6.18.17 before 6.18.55; affected 6.19.7 before 6.20 |
| Linux / Linux | affected 7.0; unaffected 0 before 7.0; unaffected 6.6.158 through 6.6.*; unaffected 6.12.112 through 6.12.*; unaffected 6.18.55 through 6.18.*; unaffected 7.2.9 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/fddc90d4af4550af410f52d11bbf6b5f36443838
- https://git.kernel.org/stable/c/0b04af3d88bb7fc69b2d92457890608860e42365
- https://git.kernel.org/stable/c/b17aa4955e3a694c663ebe99626e4c76ca4f7cfb
- https://git.kernel.org/stable/c/9b583795feb51f8d50203228d001760d1344ef01
- https://git.kernel.org/stable/c/bb756b11ad63832ebee58caf9e8f9381eaecff9f