mirrors
/
postgres
mirror of https://github.com/postgres/postgres
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Avoid crash in rare case of concurrent DROP 

When a role being dropped contains is referenced by catalog objects that
are concurrently also being dropped, a crash can result while trying to
construct the string that describes the objects.  Suppress that by
ignoring objects whose descriptions are returned as NULL.

The majority of relevant codesites were already cautious about this
already; we had just missed a couple.

This is an old bug, so backpatch all the way back.

Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/17126-21887f04508cb5c8@postgresql.org
This commit is contained in:
Alvaro Herrera 2021-11-05 12:29:35 -03:00
parent 71aeaf245b
commit e0eaeafd66
No known key found for this signature in database
GPG Key ID: 1C20ACB9D5C564AE
2 changed files with 26 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
src/backend/catalog/dependency.c
View File

@ -905,6 +905,10 @@ reportDependentObjects(const ObjectAddresses *targetObjects,
objDesc = getObjectDescription(obj);
/* An object being dropped concurrently doesn't need to be reported */
if (objDesc == NULL)
continue;
/*
* If, at any stage of the recursive search, we reached the object via
* an AUTO, INTERNAL, or EXTENSION dependency, then it's okay to
@ -928,23 +932,28 @@ reportDependentObjects(const ObjectAddresses *targetObjects,
{
char *otherDesc = getObjectDescription(&extra->dependee);
if (numReportedClient < MAX_REPORTED_DEPS)
if (otherDesc)
{
if (numReportedClient < MAX_REPORTED_DEPS)
{
/* separate entries with a newline */
if (clientdetail.len != 0)
appendStringInfoChar(&clientdetail, '\n');
appendStringInfo(&clientdetail, _("%s depends on %s"),
objDesc, otherDesc);
numReportedClient++;
}
else
numNotReportedClient++;
/* separate entries with a newline */
if (clientdetail.len != 0)
appendStringInfoChar(&clientdetail, '\n');
appendStringInfo(&clientdetail, _("%s depends on %s"),
if (logdetail.len != 0)
appendStringInfoChar(&logdetail, '\n');
appendStringInfo(&logdetail, _("%s depends on %s"),
objDesc, otherDesc);
numReportedClient++;
pfree(otherDesc);
}
else
numNotReportedClient++;
/* separate entries with a newline */
if (logdetail.len != 0)
appendStringInfoChar(&logdetail, '\n');
appendStringInfo(&logdetail, _("%s depends on %s"),
objDesc, otherDesc);
pfree(otherDesc);
ok = false;
}
else

6
src/backend/catalog/pg_shdepend.c
View File

@ -1073,6 +1073,12 @@ storeObjectDescription(StringInfo descs,
{
char *objdesc = getObjectDescription(object);
/*
* An object being dropped concurrently doesn't need to be reported.
*/
if (objdesc == NULL)
return;
/* separate entries with a newline */
if (descs->len != 0)
appendStringInfoChar(descs, '\n');