It was reported [1c that Git started to fail with an out-of-memory error
when initializing repositories with the reftable backend on NonStop
platforms. A bisect led to 802c0646ac (reftable/merged: handle
allocation failures in `merged_table_init_iter()`, 2024-10-02), which
changed how we allocate memory when initializing a merged table.
The root cause of this seems to be that NonStop returns a `NULL` pointer
when doing a zero-sized allocation. This would've already happened
before the above change, but we never noticed because we did not check
the result. Now that we do we notice and thus return an out-of-memory
error to the caller.
Fix the issue by skipping the allocation altogether in case there are no
readers.
[1]: <00ad01db5017$aa9ce340$ffd6a9c0$@nexbridge.com>
Reported-by: Randall S. Becker <rsbecker@xxxxxxxxxxxxx>
Signed-off-by: Patrick Steinhardt <ps@xxxxxx>
---
reftable/merged.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/reftable/merged.c b/reftable/merged.c
index bb0836e3443271f9c0d5ba5582c78694d437ddc2..e72b39e178d4dec6ddfca970b5af71b71431397a 100644
--- a/reftable/merged.c
+++ b/reftable/merged.c
@@ -240,14 +240,16 @@ int merged_table_init_iter(struct reftable_merged_table *mt,
struct reftable_iterator *it,
uint8_t typ)
{
- struct merged_subiter *subiters;
+ struct merged_subiter *subiters = NULL;
struct merged_iter *mi = NULL;
int ret;
- REFTABLE_CALLOC_ARRAY(subiters, mt->readers_len);
- if (!subiters) {
- ret = REFTABLE_OUT_OF_MEMORY_ERROR;
- goto out;
+ if (mt->readers_len) {
+ REFTABLE_CALLOC_ARRAY(subiters, mt->readers_len);
+ if (!subiters) {
+ ret = REFTABLE_OUT_OF_MEMORY_ERROR;
+ goto out;
+ }
}
for (size_t i = 0; i < mt->readers_len; i++) {
--
2.48.0.rc0.184.g0fc57dec57.dirty
