Description of problem:
My regular backups started to crash on the remote side.

Version-Release number of selected component (if applicable):
rsync-2.6.9-2.fc6.i386 (crashing remote server side, F6.i386)
rsync-2.6.9-2.fc7.x86_64 (local client side, F7.x86_64)

How reproducible:
Always since 2007-06-05, IIRC since upgrading local F6.x86_64 to F7.x86_64.

Steps to Reproduce:
1. host0$ /usr/bin/rsync -aHAXrxS -e ssh --delete --stats / host1:/backup

Actual results:
local side hang
on --timeout: 
 io timeout after 900 seconds -- exiting
 rsync error: timeout in data send/receive (code 30) at io.c(165) [sender=2.6.9]
on remote side `ulimit -c unlimited' wrapper:
 /usr/local/bin/rsynccore: line 4:  6137 Segmentation fault      (core dumped)
 /usr/bin/rsync "$@"
 rsync: writefd_unbuffered failed to write 4 bytes [sender]: Broken pipe (32)
 rsync: connection unexpectedly closed (1598312 bytes received so far) [sender]
 rsync error: unexplained error (code 139) at io.c(453) [sender=2.6.9]

Expected results:
Successfully synced directory tree (45GB).

Additional info:
#0  0x004d76ac in free () from /lib/libc.so.6
#1  0x0806ef87 in rsync_acl_free (racl=0x5a6ff4) at acls.c:192
#2  0x0806f446 in free_acl (sxp=0xbfa48488) at acls.c:201
#3  0x08069a68 in hard_link_cluster (file=0xb727fe70, master=1155130,
itemizing=1, code=FLOG) at hlink.c:323
#4  0x0804ba7a in check_for_finished_hlinks (itemizing=1, code=FLOG) at
generator.c:611
#5  0x0804ef2e in generate_files (f_out=1, flist=0x8788a10, local_name=0x0) at
generator.c:1531
#6  0x080588f5 in do_recv (f_in=0, f_out=1, flist=0x8788a10, local_name=0x0) at
main.c:764
#7  0x080590e0 in start_server (f_in=0, f_out=1, argc=2, argv=0x87889e8) at
main.c:871
#8  0x0805998e in main (argc=2, argv=Cannot access memory at address 0x4
) at main.c:1378
#9  0x00483f2c in __libc_start_main () from /lib/libc.so.6
#10 0x0804a811 in _start ()

Core file not supplied due to the risk of private data exposure.

Attached patch file fixes the problem although it SHOULD be reviewed.
Unaware how it relates to the upstream rsync versions.
So far able to provide more reproducibility testing but the dataset may change.