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BZ#14498: fix infinite loop in nss_db_getservbyname
- From: Alexandre Oliva <aoliva at redhat dot com>
- To: libc-alpha at sourceware dot org
- Date: Thu, 13 Nov 2014 19:52:29 -0200
- Subject: BZ#14498: fix infinite loop in nss_db_getservbyname
- Authentication-results: sourceware.org; auth=none
nss_db uses nss_files code for services, but a continue on protocol
mismatch that doesn't affect nss_files skipped the code that advanced
to the next db entry. Any one of these changes would suffice to fix
it, but fixing both makes them both safer to reuse elsewhere.
Regression tested on x86_64-linux-gnu. Ok to install?
for ChangeLog
[BZ #14498]
* NEWS: Fixed.
* nss/nss_db/db-XXX.c (_nss_db_get##name##_r): Update hidx
after parsing line but before break_if_match.
* nss/nss_files/files-service (DB_LOOKUP): Don't "continue;"
if there is a protocol mismatch.
---
NEWS | 8 ++++----
nss/nss_db/db-XXX.c | 9 ++++++---
nss/nss_files/files-service.c | 7 +++++--
3 files changed, 15 insertions(+), 9 deletions(-)
diff --git a/NEWS b/NEWS
index 918b4a1..9ed697c 100644
--- a/NEWS
+++ b/NEWS
@@ -9,10 +9,10 @@ Version 2.21
* The following bugs are resolved with this release:
- 6652, 12926, 14132, 14138, 14171, 15215, 15884, 17266, 17344, 17363,
- 17370, 17371, 17411, 17460, 17475, 17485, 17501, 17506, 17508, 17522,
- 17555, 17570, 17571, 17572, 17573, 17574, 17582, 17583, 17584, 17585,
- 17589.
+ 6652, 12926, 14132, 14138, 14171, 14498, 15215, 15884, 17266, 17344,
+ 17363, 17370, 17371, 17411, 17460, 17475, 17485, 17501, 17506, 17508,
+ 17522, 17555, 17570, 17571, 17572, 17573, 17574, 17582, 17583, 17584,
+ 17585, 17589.
* New locales: tu_IN, bh_IN.
diff --git a/nss/nss_db/db-XXX.c b/nss/nss_db/db-XXX.c
index 89b1a12..e950887 100644
--- a/nss/nss_db/db-XXX.c
+++ b/nss/nss_db/db-XXX.c
@@ -191,6 +191,12 @@ enum nss_status \
char *p = memcpy (buffer, valstr, len); \
\
int err = parse_line (p, result, data, buflen, errnop EXTRA_ARGS); \
+ \
+ /* Advance before break_if_match, lest it uses continue to skip
+ to the next entry. */ \
+ if ((hidx += hval2) >= header->dbs[i].hashsize) \
+ hidx -= header->dbs[i].hashsize; \
+ \
if (err > 0) \
{ \
status = NSS_STATUS_SUCCESS; \
@@ -203,9 +209,6 @@ enum nss_status \
status = NSS_STATUS_TRYAGAIN; \
break; \
} \
- \
- if ((hidx += hval2) >= header->dbs[i].hashsize) \
- hidx -= header->dbs[i].hashsize; \
} \
\
if (status == NSS_STATUS_NOTFOUND) \
diff --git a/nss/nss_files/files-service.c b/nss/nss_files/files-service.c
index 2401cb0..c28c62f 100644
--- a/nss/nss_files/files-service.c
+++ b/nss/nss_files/files-service.c
@@ -44,8 +44,11 @@ DB_LOOKUP (servbyname, ':',
{
/* Must match both protocol (if specified) and name. */
if (proto != NULL && strcmp (result->s_proto, proto))
- continue;
- LOOKUP_NAME (s_name, s_aliases)
+ /* A continue statement here breaks nss_db, because it
+ bypasses advancing to the next db entry, and it
+ doesn't make nss_files any more efficient. */;
+ else
+ LOOKUP_NAME (s_name, s_aliases)
},
const char *name, const char *proto)
--
Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/ FSF Latin America board member
Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer