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Infinite Loop Breakout

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There is a very rare potential, mostly in custom situations, for the 'BaseRunicTool' 'ApplySkillBonus' method to cause the server to become unresponsive.
The reason for this is that, if you call the method on a 'Spellbook' which already has all 4 of the skills listed by default in 'm_PossibleSpellbookSkills', then 'found' is always true.

This issue has been reproduced on a shard that calls 'ApplySkillBonus' more than once when crafting 'Spellbooks'; the rarity is that the 'ApplyAttributesTo' method may call the 'ApplySkillBonus' more than once; the off-chance of 5 consecutive calls, where each preceding call applies one unique skill of the 'possibleSkills', would result in the 5th call entering the deadlock state.

The fix is quite simple, evaluate the 'count' in the while statement and decrement it for each skill that is checked; removing each skill from the 'possibleSkills' list as they are checked, to prevent them being checked multiple times due to the random indices selection.
This commit is contained in:
Vorspire 2015-07-21 00:45:43 +01:00
parent 1a5653c40d
commit 1e5bc72366
1 changed files with 6 additions and 4 deletions
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10
Scripts/Items/Skill Items/Tools/BaseRunicTool.cs
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@ -1,5 +1,6 @@
using System;
using System.Collections;
using System.Collections.Generic;
namespace Server.Items
{
@ -180,7 +181,7 @@ namespace Server.Items
private static void ApplySkillBonus( AosSkillBonuses attrs, int min, int max, int index, int low, int high )
{
SkillName[] possibleSkills = ( attrs.Owner is Spellbook ? m_PossibleSpellbookSkills : m_PossibleBonusSkills );
List<SkillName> possibleSkills = new List<SkillName>( attrs.Owner is Spellbook ? m_PossibleSpellbookSkills : m_PossibleBonusSkills );
int count = ( Core.SE ? possibleSkills.Length : possibleSkills.Length - 2 );
SkillName sk, check;
@ -190,11 +191,12 @@ namespace Server.Items
do
{
found = false;
sk = possibleSkills[Utility.Random( count )];
sk = possibleSkills[Utility.Random( count-- )];
possibleSkills.Remove(sk);
for ( int i = 0; !found && i < 5; ++i )
found = ( attrs.GetValues( i, out check, out bonus ) && check == sk );
} while ( found );
} while ( found && count > 0 );
attrs.SetValues( index, sk, Scale( min, max, low, high ) );
}
@ -685,4 +687,4 @@ namespace Server.Items
}
}
}
}
}