rust/neon
1
0
Fork 0
mirror of https://github.com/neondatabase/neon.git synced 2026-01-03 19:42:55 +00:00
Code Issues Packages Projects Releases Wiki Activity

Fix out-of-boundaries access in addSHLL function (#10840)

Browse Source 
## Problem

See https://github.com/neondatabase/neon/issues/10839

rho(x,b) functions returns values in range [1,b+1] and addSHLL tries to
store it in array of size b+1.

## Summary of changes

Subtract 1 fro value returned by rho

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
This commit is contained in:
Konstantin Knizhnik
2025-02-17 14:54:17 +02:00
committed by GitHub
parent 81f08d304a
commit 8c6d133d31
1 changed files with 3 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
pgxn/neon/hll.c
View File

@@ -122,8 +122,8 @@ addSHLL(HyperLogLogState *cState, uint32 hash)
index = hash >> HLL_C_BITS;
/* Compute the rank of the remaining 32 - "k" (registerWidth) bits */
count = rho(hash << HLL_BIT_WIDTH, HLL_C_BITS);
count = rho(hash << HLL_BIT_WIDTH, HLL_C_BITS) - 1;
Assert(count <= HLL_C_BITS);
cState->regs[index][count] = now;
}
@@ -136,7 +136,7 @@ getMaximum(const TimestampTz* reg, TimestampTz since)
{
if (reg[i] >= since)
{
max = i;
max = i + 1;
}
}