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| author | Peter Geoghegan <pg@bowt.ie> | 2024-08-26 11:29:15 -0400 |
|---|---|---|
| committer | Peter Geoghegan <pg@bowt.ie> | 2024-08-26 11:29:15 -0400 |
| commit | 09a8407dbfd848301cd2c9801c3b4d75adc6cabc (patch) | |
| tree | 46d022c2976d08386e83555173b35149c0a162c3 /src | |
| parent | dbe37f1adb9fd10dc273ccf50816895360bcbc15 (diff) | |
| download | postgresql-09a8407dbfd848301cd2c9801c3b4d75adc6cabc.tar.gz postgresql-09a8407dbfd848301cd2c9801c3b4d75adc6cabc.zip | |
Fix nbtree lookahead overflow bug.
Add bounds checking to nbtree's lookahead/skip-within-a-page mechanism.
Otherwise it's possible for cases with lots of before-array-keys tuples
to overflow an int16 variable, causing the mechanism to generate an out
of bounds page offset number.
Oversight in commit 5bf748b8, which enhanced nbtree ScalarArrayOp
execution.
Reported-By: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/6c68ac42-bbb5-8b24-103e-af0e279c536f@gmail.com
Backpatch: 17-, where nbtree SAOP execution was enhanced.
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/access/nbtree/nbtutils.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/backend/access/nbtree/nbtutils.c b/src/backend/access/nbtree/nbtutils.c index d6de2072d40..c22ccec789d 100644 --- a/src/backend/access/nbtree/nbtutils.c +++ b/src/backend/access/nbtree/nbtutils.c @@ -4091,7 +4091,7 @@ _bt_checkkeys_look_ahead(IndexScanDesc scan, BTReadPageState *pstate, */ if (!pstate->targetdistance) pstate->targetdistance = LOOK_AHEAD_DEFAULT_DISTANCE; - else + else if (pstate->targetdistance < MaxIndexTuplesPerPage / 2) pstate->targetdistance *= 2; /* Don't read past the end (or before the start) of the page, though */ |