Re: bug report: "git pack-redundant --all" crash in minimize()
From: Jiang Xin <hidden>
Date: 2020-12-16 09:22:39
Subsystem:
the rest · Maintainer:
Linus Torvalds
Jeff King [off-list ref] 于2020年12月16日周三 上午2:24写道：
quoted hunk ↗ jump to hunk
On Tue, Dec 15, 2020 at 06:34:53PM +0100, Daniel C. Klauer wrote:quoted
I'm getting the following crash from "git pack-redundant --all" (output from valgrind): ==14070== Invalid read of size 8 ==14070== at 0x18F165: minimize (pack-redundant.c:399) ==14070== by 0x18F165: cmd_pack_redundant (pack-redundant.c:622) ==14070== by 0x1242D3: run_builtin (git.c:444) ==14070== by 0x1242D3: handle_builtin (git.c:674) ==14070== by 0x125393: run_argv (git.c:741) ==14070== by 0x125393: cmd_main (git.c:872) ==14070== by 0x123E7D: main (common-main.c:52) ==14070== Address 0x10 is not stack'd, malloc'd or (recently) free'd Commands to reproduce: mkdir new cd new git init touch foo.txt git add foo.txt git commit -m "first commit" git gc git pack-redundant --allThanks for an easy reproduction. This bisects to 3011177640 (pack-redundant: delay creation of unique_objects, 2019-02-02). I suspect the fix is just:diff --git a/builtin/pack-redundant.c b/builtin/pack-redundant.c index 3e70f2a4c1..68afcfeb7b 100644 --- a/builtin/pack-redundant.c +++ b/builtin/pack-redundant.c@@ -396,7 +396,7 @@ static void minimize(struct pack_list **min) pl = local_packs; while (pl) { - if (pl->unique_objects->size) + if (pl->unique_objects && pl->unique_objects->size) pack_list_insert(&unique, pl); else pack_list_insert(&non_unique, pl);but I didn't look closely (author cc'd).
Will fix like this:
pack-redundant: fix crash when one packfile in repo
Command `git pack-redundant --all` will crash if there is only one
packfile in the repository. This is because, if there is only one
packfile in local_packs, `cmp_local_packs` will do nothing and will
leave `pl->unique_objects` as uninitialized.
... ...
diff --git a/builtin/pack-redundant.c b/builtin/pack-redundant.c
index 178e3409b7..9b0646a5e2 100644
--- a/builtin/pack-redundant.c
+++ b/builtin/pack-redundant.c@@ -473,6 +473,12 @@ static void cmp_local_packs(void) { struct pack_list *subset, *pl = local_packs; + /* only one packfile */ + if (!pl->next && !pl->unique_objects) { + llist_init(&pl->unique_objects); + return; + } + while ((subset = pl)) { while ((subset = subset->next)) cmp_two_packs(pl, subset);