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| author | Eelco Dolstra <eelco.dolstra@logicblox.com> | 2013-02-04 15:56:26 +0100 |
|---|---|---|
| committer | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2013-02-07 01:02:33 -0500 |
| commit | d2f1f23ad2636cf05589a67b5229c7fd604bc21f (patch) | |
| tree | 96d3821b0e03230b6797b7c8cf5665e62df2cb9d /src/nss-myhostname | |
| parent | 13219b7f74cb2722746b953bbec7593d5cc665e3 (diff) | |
| download | systemd-d2f1f23ad2636cf05589a67b5229c7fd604bc21f.tar.gz | |
nss-myhostname: copy first result to preallocated buffer
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.
Diffstat (limited to 'src/nss-myhostname')
| -rw-r--r-- | src/nss-myhostname/nss-myhostname.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/src/nss-myhostname/nss-myhostname.c b/src/nss-myhostname/nss-myhostname.c index 834a80690f..b0fb8323ad 100644 --- a/src/nss-myhostname/nss-myhostname.c +++ b/src/nss-myhostname/nss-myhostname.c @@ -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; |