libnl: report an error if unexpected control data was received

Currently, we try to handle MSG_CTRUNC, but if msg_controllen is zero, we make
double free for the same address.

realloc(0, 0) returns non-zero address
realloc(addr, 0) returns zero and free(addr) has already been called

Then we call free(addr) again and get an error like this:

*** Error in `./task_diag_all': double free or corruption (fasttop): 0x0000000000f9c160 ***
======= Backtrace: =========
/lib64/libc.so.6(+0x77e9d)[0x7f360ed96e9d]
/lib64/libc.so.6(+0x7f53c)[0x7f360ed9e53c]
/lib64/libc.so.6(cfree+0x4c)[0x7f360eda2e9c]
/lib64/libnl-3.so.200(nl_recv+0x221)[0x7f360f2f6361]
/lib64/libnl-3.so.200(nl_recvmsgs_report+0x555)[0x7f360f2f6a95]
/lib64/libnl-3.so.200(nl_recvmsgs+0x9)[0x7f360f2f6d89]
./task_diag_all[0x400f8d]
/lib64/libc.so.6(__libc_start_main+0xf0)[0x7f360ed3f790]
./task_diag_all[0x401169]

http://lists.infradead.org/pipermail/libnl/2015-September/001965.html

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Thomas Haller <thaller@redhat.com>

0 files changed, 0 insertions, 0 deletions