diff options
| author | Christoffer Dall <christoffer.dall@linaro.org> | 2016-08-02 22:05:42 +0200 |
|---|---|---|
| committer | Christoffer Dall <christoffer.dall@linaro.org> | 2016-08-10 11:41:54 +0200 |
| commit | 2cccbb368a2bf27d98cf36bb424fbbf5572c0fab (patch) | |
| tree | 83edb3161029df208d04341330a381b8c6e9f5a1 | |
| parent | 99e5e886a0a59df267ff6838f763b789847df982 (diff) | |
KVM: arm64: vgic-its: Plug race in vgic_put_irq
Right now the following sequence of events can happen:
1. Thread X calls vgic_put_irq
2. Thread Y calls vgic_add_lpi
3. Thread Y gets lpi_list_lock
4. Thread X drops the ref count to 0 and blocks on lpi_list_lock
5. Thread Y finds the irq via the lpi_list_lock, raises the ref
count to 1, and release the lpi_list_lock.
6. Thread X proceeds and frees the irq.
Avoid this by holding the spinlock around the kref_put.
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>