| commit | a2e1753b8054344f32cf94f31c6399a58794a380 | [log] [tgz] |
|---|---|---|
| author | Alexander Bulekov <alxndr@bu.edu> | Thu Apr 27 17:10:06 2023 -0400 |
| committer | Thomas Huth <thuth@redhat.com> | Fri Apr 28 11:20:01 2023 +0200 |
| tree | 73c716abd3831946029a0ea185659cb99ebf1bbb | |
| parent | 3ee7f21ed292966f5cd3eb71aa06f8ffc0e5ae41 [diff] |
memory: prevent dma-reentracy issues Add a flag to the DeviceState, when a device is engaged in PIO/MMIO/DMA. This flag is set/checked prior to calling a device's MemoryRegion handlers, and set when device code initiates DMA. The purpose of this flag is to prevent two types of DMA-based reentrancy issues: 1.) mmio -> dma -> mmio case 2.) bh -> dma write -> mmio case These issues have led to problems such as stack-exhaustion and use-after-frees. Summary of the problem from Peter Maydell: https://lore.kernel.org/qemu-devel/CAFEAcA_23vc7hE3iaM-JVA6W38LK4hJoWae5KcknhPRD5fPBZA@mail.gmail.com Resolves: https://gitlab.com/qemu-project/qemu/-/issues/62 Resolves: https://gitlab.com/qemu-project/qemu/-/issues/540 Resolves: https://gitlab.com/qemu-project/qemu/-/issues/541 Resolves: https://gitlab.com/qemu-project/qemu/-/issues/556 Resolves: https://gitlab.com/qemu-project/qemu/-/issues/557 Resolves: https://gitlab.com/qemu-project/qemu/-/issues/827 Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1282 Resolves: CVE-2023-0330 Signed-off-by: Alexander Bulekov <alxndr@bu.edu> Reviewed-by: Thomas Huth <thuth@redhat.com> Message-Id: <20230427211013.2994127-2-alxndr@bu.edu> [thuth: Replace warn_report() with warn_report_once()] Signed-off-by: Thomas Huth <thuth@redhat.com>