xfree86: device parser fix crash with duplicate "Clocks" property #1416
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This commit fixes when processing the first line, the clock frequency value ptr->dev_clocks is 0. If the first line of the clock frequency contains 100 values, the clock frequency value ptr->dev_clocks will be 100. When processing the second row "Clocks", which contains, for example, 100 more values, the loop will start with i = 100. This will cause 72 values to be written outside the 128-element dev_block array, which will lead to buffer overflow and an emergency crash xserver.
Contributor
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does this also need to be backported to maint-25.0 ? |
stefan11111
reviewed
Nov 22, 2025
| break; | ||
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| case CLOCKS: | ||
| ptr->dev_clocks = 0; |
Contributor
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Why are we setting this to 0 here?
It is overwritten after a few lines.
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Related to issue: #1407
This commit fixes when processing the first line, the clock frequency value ptr->dev_clocks is 0. If the first line of the clock frequency contains 100 values, the clock frequency value ptr->dev_clocks will be 100. When processing the second row "Clocks", which contains, for example, 100 more values, the loop will start with i = 100. This will cause 72 values to be written outside the 128-element dev_block array, which will lead to buffer overflow and an emergency crash xserver.