uc_mem: reject address+size wrap-around in check_mem_area#2324
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uc_mem: reject address+size wrap-around in check_mem_area#2324MarkLee131 wants to merge 1 commit into
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uc_mem_map() rejects address+size wrap-around in mem_map_check(), but
uc_mem_read/write/unmap/protect() didn't have the same guard. They go
through check_mem_area(), which iterated pages without an overflow
check and happily walked from the top of the address space back to 0
when a low page was also mapped.
Concretely, with two legal mappings at the top page and at address 0:
- uc_mem_read(top, buf, 0x2000) writes 0x2000 bytes into a 0x1000
buffer (host heap-overflow into the caller's storage) and returns
UC_ERR_OK.
- uc_mem_write mirrors that as a 0x1000 OOB read of the source.
- uc_mem_unmap returns OK and silently drops both regions.
- uc_mem_protect returns OK and demotes both regions' permissions.
Adding the wrap check inside check_mem_area() lets the four callers
keep their existing not-mapped error codes (READ_UNMAPPED /
WRITE_UNMAPPED / NOMEM) without any per-call-site changes.
Adds a regression test in tests/unit/test_mem.c that maps both pages,
exercises all four entry points with a wrapping range, and checks that
the non-wrapping single-page case still works.
Closes unicorn-engine#1641. Fixes unicorn-engine#2321.
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uc_mem_map() rejects address+size wrap-around in mem_map_check(), but uc_mem_read/write/unmap/protect() didn't have the same guard. They go through check_mem_area(), which iterated pages without an overflow check and happily walked from the top of the address space back to 0 when a low page was also mapped.
Concretely, with two legal mappings at the top page and at address 0:
Adding the wrap check inside check_mem_area() lets the four callers keep their existing not-mapped error codes (READ_UNMAPPED / WRITE_UNMAPPED / NOMEM) without any per-call-site changes.
Adds a regression test in tests/unit/test_mem.c that maps both pages, exercises all four entry points with a wrapping range, and checks that the non-wrapping single-page case still works.
Closes #1641. Fixes #2321.