@leroysheep / CrazyWebTemps / commits / 64b6922562

patch-id: discard hash when done

When computing a patch-id, we have a flush_one_hunk() helper that calls git_hash_final() on our running hunk git_hash_ctx, and then reinitializes that context for the next hunk. When we run out of hunks to look at, we return, discarding the git_hash_ctx. This can cause a leak if the hash implementation we are using allocates any memory during its initialization. This includes OpenSSL >= 3.0, for both SHA-1 and SHA-256. Normally we would not use SHA-1 here at all, as we only recommend using non-DC implementations for the "unsafe" variant (and patch-id, though they probably _could_ use the unsafe variant, were never taught to do so). But it is certainly a problem for SHA-256, which you can see with: make SANITIZE=leak \ OPENSSL_SHA256=1 \ GIT_TEST_DEFAULT_HASH=sha256 \ test That results in leak failures of 60 scripts, 57 of which are fixed by this patch (basically anything which runs rebase will hit this case). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Jul 2, 2026 at 04:04 UTC 64b69225620a4119e1ee6e02620c56a58dc442fb

2 files changed +2

builtin/patch-id.c

index 2781598ede..57d9bd4a65 100644 --- a/builtin/patch-id.c +++ b/builtin/patch-id.c @@ -173,6 +173,7 @@ static size_t get_one_patchid(struct object_id *next_oid, struct object_id *resu oidclr(next_oid, the_repository->hash_algo); flush_one_hunk(result, &ctx); + git_hash_discard(&ctx); return patchlen; }

diff.c

index 397e38b41c..f631bf1e2a 100644 --- a/diff.c +++ b/diff.c @@ -6958,6 +6958,7 @@ static int diff_get_patch_id(struct diff_options *options, struct object_id *oid flush_one_hunk(oid, &ctx); } + git_hash_discard(&ctx); return 0; }