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53 lines
2.3 KiB
53 lines
2.3 KiB
commit b048a482f088e53144d26a61c390bed0210f49f2 |
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Author: Florian Weimer <fweimer@redhat.com> |
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Date: Thu Apr 25 15:01:07 2024 +0200 |
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CVE-2024-33600: nscd: Avoid null pointer crashes after notfound response (bug 31678) |
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The addgetnetgrentX call in addinnetgrX may have failed to produce |
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a result, so the result variable in addinnetgrX can be NULL. |
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Use db->negtimeout as the fallback value if there is no result data; |
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the timeout is also overwritten below. |
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Also avoid sending a second not-found response. (The client |
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disconnects after receiving the first response, so the data stream did |
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not go out of sync even without this fix.) It is still beneficial to |
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add the negative response to the mapping, so that the client can get |
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it from there in the future, instead of going through the socket. |
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Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org> |
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diff --git a/nscd/netgroupcache.c b/nscd/netgroupcache.c |
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index 08668e96a9fd2c77..5ed16f871c433531 100644 |
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--- a/nscd/netgroupcache.c |
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+++ b/nscd/netgroupcache.c |
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@@ -512,14 +512,15 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req, |
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datahead_init_pos (&dataset->head, sizeof (*dataset) + req->key_len, |
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sizeof (innetgroup_response_header), |
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- he == NULL ? 0 : dh->nreloads + 1, result->head.ttl); |
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+ he == NULL ? 0 : dh->nreloads + 1, |
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+ result == NULL ? db->negtimeout : result->head.ttl); |
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/* Set the notfound status and timeout based on the result from |
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getnetgrent. */ |
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- dataset->head.notfound = result->head.notfound; |
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+ dataset->head.notfound = result == NULL || result->head.notfound; |
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dataset->head.timeout = timeout; |
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dataset->resp.version = NSCD_VERSION; |
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- dataset->resp.found = result->resp.found; |
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+ dataset->resp.found = result != NULL && result->resp.found; |
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/* Until we find a matching entry the result is 0. */ |
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dataset->resp.result = 0; |
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@@ -567,7 +568,9 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req, |
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goto out; |
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} |
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- if (he == NULL) |
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+ /* addgetnetgrentX may have already sent a notfound response. Do |
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+ not send another one. */ |
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+ if (he == NULL && dataset->resp.found) |
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{ |
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/* We write the dataset before inserting it to the database |
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since while inserting this thread might block and so would
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