Remove tv_str and use a unsigned int for slot in mkstr#526
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Remove tv_str and use a unsigned int for slot in mkstr#526
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…will increase slot++ in mkstr Signed-off-by: nook24 <d.ziegler@avendis.com>
The static 'slot' variable in mkstr() was previously a signed 32-bit integer. On high-load systems (e.g., during status data dumps), this counter could overflow, becoming negative. In C, a negative dividend with the modulo operator (slot % 256) results in a negative index. This caused the 'ret' pointer to point to memory addresses BEFORE the actual buffer. In our case, this led to a SIGSEGV because a timestamp string was written directly over the 'contact_list' pointer, which happened to be located in that memory region. Changes: - Changed 'slot' from signed int to unsigned int (uint) to ensure the modulo result is always positive and within buffer bounds. - This ensures that upon reaching UINT_MAX, the counter wraps safely back to zero. Signed-off-by: nook24 <d.ziegler@avendis.com>
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Please see #527 |
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We have noticed random segfaults on one of our systems during the creating of
status.dat.Since Naemon 1.5.0,
tv_stris called in the For-loop for each host and service status object, which will increase the counter ofslotby one each time. After 2.147.483.647 the integer will flip into -2.147.483.648 and modulo of a negativ dividend will result in a negativ value in C (and PHP, Go JavaScript).When reading
buf[-2147468803]whatever is at this address will be overwritten.