io_uring/register: don't exempt disabled rings from task restrictions
Impact
In the Linux kernel, the following vulnerability has been resolved:
Source excerpt · LinuxEnabling such a ring now requires IORING_REGISTER_ENABLE_RINGS to be in the task's allowed set.
Affected packages
Affected products
Vendor version evidence. Product records are separate from automatic dependency matching.
Linux · Linux
Other versions: unaffected
| Version / range | Source status |
|---|---|
| ed82f35b926b2e505c14b7006473614b8f58b4f4 to before f55c240192ded562386de843bfa067671d2731d5 | affected |
| ed82f35b926b2e505c14b7006473614b8f58b4f4 to before 6da8f402e362b2f546e2efb7167fc9597aef6faf | affected |
Linux · Linux
Other versions: affected
| Version / range | Source status |
|---|---|
| 7.0 | affected |
| 0 to before 7.0 | unaffected |
| 7.2.11 through 7.2.* (inclusive) | unaffected |
| 7.3 through * (inclusive) | unaffected |
Original source description
In the Linux kernel, the following vulnerability has been resolved:
io_uring/register: don't exempt disabled rings from task restrictions
A ring created with IORING_SETUP_R_DISABLED is exempt from its register restrictions until it is enabled. This lets the creator register the restrictions and then enable the ring with IORING_REGISTER_ENABLE_RINGS, whether or not that opcode is in the allowed set.
Since commit ed82f35b926b ("io_uring: allow registration of per-task restrictions"), a ring also inherits restrictions from the task that creates it, and the same exemption applies to those. A task whose register opcodes are restricted can therefore create a disabled ring, issue any register opcode on it, and then enable it.
Mark rings whose restrictions were inherited from the task, and keep checking register opcodes for them while the ring is disabled. Enabling such a ring now requires IORING_REGISTER_ENABLE_RINGS to be in the task's allowed set. Per-ring restrictions registered on a disabled ring work as before.
[axboe: amend with inheritance flag fixup]