Re: Crash of mod_dav_svn Apache thread in membuf_create() at subversion/libsvn_subr/string.c:58

Szőts Ákos <szotsaki_at_gmail.com> writes:

> When I update my repository, from time to time Apache threads crash with
> Subversion functions appearing on the top.
>
> I use SVN with mod_dav_svn via HTTPS connections.
>
> Versions:
> OS: openSUSE 13.2 x64
> Kernel: 3.16.7
> apache2-prefork: 2.4.10
> subversion and subversion_server: 1.8.13

> Full backtrace:
> #0 apr_palloc (pool=pool_at_entry=0x7fbc49587028, in_size=in_size_at_entry=48) at
> memory/unix/apr_pools.c:684
> active = 0x30312037310a0a0a

That value looks like text: "01 71\n\n\n", so the heap appears to be
corrupt. If you have a core file then looking at other memory nearby,
things like pool->tag and pool->self, might help.

The pool pointer 0x7fbc49587028 is r->pool passed all the way through
from here:

#15 0x00007fbc4d390538 in svn_repos_has_capability (repos=0x7fbc4958d490, has=has_at_entry=0x7fff6437f290, capability=<optimized out>, capability_at_entry=0x7fbc4d5c90d9 "mergeinfo", pool=0x7fbc4955c028) at subversion/libsvn_repos/repos.c:1635
        svn_err__temp = <optimized out>
        err = <optimized out>
        root = 0x1300000010
        ignored = 0x7fbc49551748
        paths = 0x7fbc495811c0
        val = <optimized out>
#16 0x00007fbc4d5c2bfa in get_option (resource=0x7fbc4956ebe8, elem=0x7fbc49551560, option=0x7fff6437f370) at subversion/mod_dav_svn/version.c:252
        serr = <optimized out>
        has = 1230508376
        r = 0x7fbc4955c0a0
        repos_root_uri = 0x7fbc49551cc0 "/svn/skyrim"
#17 0x00007fbc500f9337 in dav_method_options (r=r_at_entry=0x7fbc4955c0a0) at mod_dav.c:1892

That is early in Subversion's handling of the request. Subversion might
be responsible for the corruption, but it is also possible that some
other Apache module was responsible.

-- 
Philip Martin | Subversion Committer
WANdisco // *Non-Stop Data*