Fix potential OOB read in zend_dirname() on Windows #16995
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Only on Windows `IS_SLASH_P()` may read the previous byte, and so may in unlikely cases read one byte out of bounds. Since `IS_SLASH_P()` is in a public header (albeit not likely to be used by external extensions or SAPIs), we introduce `IS_SLASH_P_EX()` which accepts a second argument to prevent that OOB read. It should be noted that the PHP userland function `dirname()` is not affected by this issue, since it does not call `zend_dirname()` on Windows.
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No ABI break here. |
nielsdos
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Nov 29, 2024
charmitro
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Mar 13, 2025
Only on Windows `IS_SLASH_P()` may read the previous byte, and so may in unlikely cases read one byte out of bounds. Since `IS_SLASH_P()` is in a public header (albeit not likely to be used by external extensions or SAPIs), we introduce `IS_SLASH_P_EX()` which accepts a second argument to prevent that OOB read. It should be noted that the PHP userland function `dirname()` is not affected by this issue, since it does not call `zend_dirname()` on Windows. Closes phpGH-16995.
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Only on Windows
IS_SLASH_P()may read the previous byte, and so may in unlikely cases read one byte out of bounds. SinceIS_SLASH_P()is in a public header (albeit not likely to be used by external extensions or SAPIs), we introduceIS_SLASH_P_EX()which accepts a second argument to prevent that OOB read.It should be noted that the PHP userland function
dirname()is not affected by this issue, since it does not callzend_dirname()on Windows.