diff options
| author | Kevin Lourenco <klourencodev@gmail.com> | 2025-12-29 17:13:21 +0100 |
|---|---|---|
| committer | Mike Rapoport (Microsoft) <rppt@kernel.org> | 2026-01-09 11:53:51 +0200 |
| commit | f56ccc32468ee7885d3a9175e7d2cb608d301521 (patch) | |
| tree | 65e1b0a398d3949843c6abeae1c982293dd2b497 | |
| parent | 58e3e5265484a1bf39569903630a45a924621aaa (diff) | |
mm/memtest: add underflow detection for size calculation
The computation:
end = start + (size - (start_phys_aligned - start_phys)) / incr
could theoretically underflow if size < offset, leading to a massive
iteration.
Add VM_WARN_ON_ONCE() to detect cases where the region size is smaller
than the alignment offset. While this should never happen in practice
due to memblock guarantees, the warning helps catch potential bugs in
early memory initialization code.
Suggested-by: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Kevin Lourenco <klourencodev@gmail.com>
Link: https://patch.msgid.link/20251229161321.9079-1-klourencodev@gmail.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
| -rw-r--r-- | mm/memtest.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/memtest.c b/mm/memtest.c index c2c609c39119..520d41534cfa 100644 --- a/mm/memtest.c +++ b/mm/memtest.c @@ -50,6 +50,8 @@ static void __init memtest(u64 pattern, phys_addr_t start_phys, phys_addr_t size start_bad = 0; last_bad = 0; + VM_WARN_ON_ONCE(size < start_phys_aligned - start_phys); + for (p = start; p < end; p++) WRITE_ONCE(*p, pattern); |