rsync crashing under centos 4
John Van Essen
vanes002 at umn.edu
Fri Mar 11 18:10:53 GMT 2005
On Thu, 10 Mar 2005, Joe Pruett <joey at clean.q7.com> wrote:
> the rsync in centos 4 (a recompile of rhel4) is version 2.6.3. and under
> certain circumstances it will segfault when run in daemon mode. i have
> tracked it down to the nss code in libc. so this could be a general libc
> bug, but it is possible that rsync is doing things that don't help matters
> the problem manifests when you have chroot mode on (which seems to be the
> default), have files on the server owned by someone other than root, and
> request an rsync with -o enabled. this causes the server process to try
> to call getpwuid for the file uid and things segfault. ...
A similar problem was reported back in February:
that manifested itself after an upgrade to Fedora Core 2. It had worked
fine previously (on FC1, presumably).
That user (David Blunkett) provided an strace log that showed this:
[pid 27916] open("/usr/lib/libnss_compat.so.2", O_RDONLY) = -1 ENOENT (No such file or directory)
[pid 27916] stat64("/usr/lib", 0xfef74ac8) = -1 ENOENT (No such file or directory)
[pid 27916] --- SIGSEGV (Segmentation fault) @ 0 (0) ---
where it's trying to load a dynamically linked library and ends up
crapping out at the end. So this is a problem with some run-time
dynamically linked library failing to load. But why the delayed
load attempt? Aren't these supposed to be resolved when the program
is initially loaded at run-time?
This has not been a problem in the past, AFAIK.
Perhaps some newer library is trying to be too clever for its own good.
As a workaround, maybe rsync could do a call to getpwuid() and getgrgid()
before doing the chroot to make sure it has the required library loaded?
John Van Essen Univ of Minn. Alumnus <vanes002 at umn.edu>
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