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| author | Alexander Bulekov <alxndr@bu.edu> | 2023-04-27 17:10:06 -0400 |
|---|---|---|
| committer | Thomas Huth <thuth@redhat.com> | 2023-04-28 11:20:01 +0200 |
| commit | a2e1753b8054344f32cf94f31c6399a58794a380 (patch) | |
| tree | 73c716abd3831946029a0ea185659cb99ebf1bbb /docs | |
| parent | 3ee7f21ed292966f5cd3eb71aa06f8ffc0e5ae41 (diff) | |
| download | qemu-a2e1753b8054344f32cf94f31c6399a58794a380.zip qemu-a2e1753b8054344f32cf94f31c6399a58794a380.tar.gz qemu-a2e1753b8054344f32cf94f31c6399a58794a380.tar.bz2 | |
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>
Diffstat (limited to 'docs')
0 files changed, 0 insertions, 0 deletions