[release/9.0] Avoid signed overflow in DBG_FlushInstructionCache #106823
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On ARM32 Linux we can have an infinite loop because of integer overflow. For example, if DBG_FlushInstructionCache is called with the following parameters & locals: dwSize = 28 pageSize = 4096 begin = lpBaseAddress = 0x7ffff000 end = begin + dwSize = 0x7ffff01c ALIGN_UP(0x7ffff000, 4096) returns 0x80000000 which is actually a negative number because INT_PTR is just int32_t (on ARM32). And here we are getting an infinite loop because "begin" will never be greater or equal than "end". So, this issue is related to all addresses between INT32_MAX - PAGE_SIZE and INT32_MAX because ALIGN_UP returns the address of the next page which will be greater or equal to INT32_MAX Signed-off-by: Andrei Lalaev <[email protected]>
jkotas
approved these changes
Aug 22, 2024
jeffschwMSFT
approved these changes
Aug 22, 2024
This was referenced Aug 22, 2024
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Backport of #105918 to release/9.0
/cc @jkotas @AndreyLalaev
Customer Impact
Intermittent hang (infinite loop) on some Linux Arm32 systems.
Regression
Testing
Fix proposed and validated by the customer
Risk
Low
IMPORTANT: If this backport is for a servicing release, please verify that:
The PR target branch is
release/X.0-staging, notrelease/X.0.If the change touches code that ships in a NuGet package, you have added the necessary package authoring and gotten it explicitly reviewed.