[lxml-dev] xmlHashComputeKey crash

[Stefan Behnel]

Hi,

Kevin Watters wrote:
> I've been getting crash reports from a user--the app is crashing when "import 
> lxml.etree" happens. Unfortunately the default lxml build (for Windows, at 
> least) doesn't include /Zi flags to build PDB files--so the stack doesn't 
> include function names for the lxml bits.
> 
> I'll be recompiling with /Zi, but still, I thought maybe I would ask here to 
> see if anyone had run into this:
> 
> 036ccbe0 01de0578 026a9128 10010ef8 05690ee0 libxml2!xmlHashComputeKey+0x12
> 036ccc04 01de0b3d 026a9128 10010ef8 05690ee0 libxml2!xmlHashUpdateEntry3+0xec
> 036ccc24 02bb2aee 026a9128 10010ef8 05690ee0 libxml2!xmlHashUpdateEntry2+0x19
> 036ccc40 0568c956 10010ef8 05690ee0 0568c6fb 
> libxslt!xsltRegisterExtModuleFunction+0x54
> 036ccc54 0568cc30 03df5810 05629b42 00000000 libexslt!exsltCryptoRegister+0x45
> 036ccc5c 05629b42 00000000 03dd8b24 03dda424 libexslt!exsltRegisterAll+0xd
> WARNING: Stack unwind information not available. Following frames may be wrong.
> 036ccd08 1e0769ab 1e076210 03dd8b98 00000000 lxml_etree!initetree+0xdd22
> 036ccd1c 1e076276 03dda424 00b7f828 00000000 
> python25!_PyImport_LoadDynamicModule+0x7b
> 036ccd34 1e087247 00000000 03dd8b98 00b7f828 python25!imp_load_dynamic+0x66
> 036ccd4c 1e03aa81 00b7f828 03dd8b98 00000000 python25!PyCFunction_Call+0x47
> 036ccd7c 1e038b9b 036ccde0 00000000 03e07c40 python25!call_function+0x2b1
> 036ccdf8 1e03abd5 03e07c40 00000000 03dd62b0 python25!PyEval_EvalFrameEx+0x210b
> 036cce14 1e03aaf8 036ccea8 00000000 00000000 python25!fast_function+0x85
> 
> The xsltRegisterExtModuleFunction gets an xmlChar* "name" argument that appears 
> to be a bad pointer, and is eventually accessed in xmlHashComputeKey.

thanks for the report. Could you add what version of lxml and especially
libxml2 and libxslt you are using? This actually looks more like a problem in
libxml2 or libexslt, although I never stumbled over anything related so far.

Stefan