Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: gpio: sch: use raw_spinlock_t in the irq startup path sch_irq_unmask() enables the GPIO IRQ and then updates the controller state through sch_irq_mask_unmask(), which takes sch->lock with spin_lock_irqsave(). The callback can be reached from irq_startup() while setting up a requested IRQ. That path is not sleepable, but on PREEMPT_RT a regular spinlock_t becomes a sleeping lock. This issue was found by our static analysis tool and then manually reviewed against the current tree. The grounded PoC kept the request_threaded_irq() -> __setup_irq() -> irq_startup() -> sch_irq_unmask() -> sch_irq_mask_unmask() carrier and used the original spin_lock_irqsave(&sch->lock) edge. Lockdep reported: BUG: sleeping function called from invalid context hardirqs last disabled at ... __setup_irq.constprop.0 ... [vuln_msv] sch_rt_spin_lock_irqsave+0x1c/0x30 [vuln_msv] sch_irq_mask_unmask.constprop.0+0x31/0x70 [vuln_msv] __setup_irq.constprop.0+0xd/0x30 [vuln_msv] Convert the SCH controller lock to raw_spinlock_t. The same lock is also used by the GPIO direction and value callbacks, but those critical sections only update MMIO-backed GPIO registers and do not contain sleepable operations. Keeping this register lock non-sleeping is therefore appropriate for the irqchip callbacks and does not change the GPIO-side locking contract.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 7a81638485c1a62a87b4c391ecc9c651a4a9dc19 before 3b1aa05ec27eeccc889ecaa3f2d9baa9f453e50d; affected 7a81638485c1a62a87b4c391ecc9c651a4a9dc19 before 4f03a15cc73c83740fc355ee22b336492d17b4da; affected 7a81638485c1a62a87b4c391ecc9c651a4a9dc19 before 7a550256d68bbdfa0903ab1c4595c04a6815493a; affected 7a81638485c1a62a87b4c391ecc9c651a4a9dc19 before a235cec779bb39ec8f961a935b28a2ce278c6c64; affected 7a81638485c1a62a87b4c391ecc9c651a4a9dc19 before 4508366ab7dd0c2917a51a9c2e23cc1b9d35157a; affected 7a81638485c1a62a87b4c391ecc9c651a4a9dc19 before 41cad91a09d69e8fff4e936db29b1054b4e9f9f7; affected 7a81638485c1a62a87b4c391ecc9c651a4a9dc19 before 286533cb14a3c8a8bd39ff64ea2fc8e1aa0f638b |
| Linux / Linux | affected 5.13; unaffected 0 before 5.13; unaffected 5.15.212 through 5.15.*; unaffected 6.1.178 through 6.1.*; unaffected 6.6.145 through 6.6.*; unaffected 6.12.97 through 6.12.*; unaffected 6.18.39 through 6.18.*; unaffected 7.1.4 through 7.1.*; unaffected 7.2 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/3b1aa05ec27eeccc889ecaa3f2d9baa9f453e50d
- https://git.kernel.org/stable/c/4f03a15cc73c83740fc355ee22b336492d17b4da
- https://git.kernel.org/stable/c/7a550256d68bbdfa0903ab1c4595c04a6815493a
- https://git.kernel.org/stable/c/a235cec779bb39ec8f961a935b28a2ce278c6c64
- https://git.kernel.org/stable/c/4508366ab7dd0c2917a51a9c2e23cc1b9d35157a
- https://git.kernel.org/stable/c/41cad91a09d69e8fff4e936db29b1054b4e9f9f7
- https://git.kernel.org/stable/c/286533cb14a3c8a8bd39ff64ea2fc8e1aa0f638b