On Wed, 28 Mar 2018 16:14:04 +0200 Tomas Vondra <tomas.von...@2ndquadrant.com> wrote:
> On 03/28/2018 03:54 PM, Nicolas Thauvin wrote: > > Hello, > > > > A customer sent us a core dump of the crash of the background > > worker of the powa extension, running on 9.6.8 along side with > > cstore_fdw. > > > > The background worker loops on a plpgsql function, which then > > execute another plpgsql function that issues the query "TRUNCATE > > powa_statements_history_current". > > > > Here is the backtrace : > > > > ... > > > > The core shows that ProcessUtility hook of cstore_fdw produces a > > segfault when trying to copy the relation list of the truncate > > statement plan. > > > > In frame 2: > > (gdb) p *((TruncateStmt *)parseTree) > > $26 = {type = T_TruncateStmt, relations = 0x2f106a8, restart_seqs = > > 0 '\000', behavior = DROP_RESTRICT} (gdb) p *(((TruncateStmt > > *)parseTree)->relations) $27 = {type = 49574520, length = 0, head = > > 0x0, tail = 0x2faaab8} > > > > With this invalid list, standard_ProcessUtility would not have > > failed but the relation would not have been truncated. > > > > ... > > > > Could you please give me some pointers to further investigate this > > crash? > > > > Sounds like a bug in CStoreProcessUtility, which is part of > cstore_fdw, not PostgreSQL. So I guess the right place to report the > issue is > > https://github.com/citusdata/cstore_fdw > > Having a second look at the code of cstore_fdw, it modifies the data. I'll investigate more on this code. Thank you -- Nicolas Thauvin +33 (0)1 84 16 92 09 http://dalibo.com - http://dalibo.org