shaba/systemd
1
0
Fork 0
mirror of https://github.com/systemd/systemd.git synced 2024-12-25 01:34:28 +03:00
Code

nss-myhostname: copy first result to preallocated buffer

Browse Source 
Fixes a segfault in nscd when using nss-myhostname.

Nscd expects that an NSS module's gethostbyname4_r function returns
its first result in the pre-allocated gaih_addrtuple denoted by **pat.
(See nscd/aicache.c in the Glibc sources.)  However, nss-myhostname
doesn't fill in **pat but allocates the first result in ‘buffer’, then
sets *pat.  So nscd crashes (e.g. when running ‘getent ahosts
my-machine’).

Hard to tell if this is a bug in nscd, since there doesn't seem to be
a proper API spec for gethostbyname4_r.  But in any case, this patch
fixes the crash by copying the first result to **pat.
This commit is contained in:
Eelco Dolstra 2013-02-04 15:56:26 +01:00 committed by Zbigniew Jędrzejewski-Szmek
parent 13219b7f74
commit d2f1f23ad2
1 changed files with 5 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/nss-myhostname/nss-myhostname.c
View File

@ -176,7 +176,11 @@ enum nss_status _nss_myhostname_gethostbyname4_r(
/* Verify the size matches */
assert(idx == ms);
*pat = r_tuple_prev;
/* Nscd expects us to store the first record in **pat. */
if (*pat)
**pat = *r_tuple_prev;
else
*pat = r_tuple_prev;
if (ttlp)
*ttlp = 0;