| Message ID | patch-1.2-e5ef1be2aa9-20211006T093405Z-avarab@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | dir & unpak-trees: memory-leak fixes | expand |
On Wed, Oct 6, 2021 at 2:40 AM Ævar Arnfjörð Bjarmason <avarab@gmail.com> wrote: > > Fix two different but related memory leaks in > verify_clean_subdirectory(). We leaked both the "pathbuf" if > read_directory() returned non-zero, and we never cleaned up our own > "struct dir_struct" either. > > * "pathbuf": When the read_directory() call followed by the > free(pathbuf) was added in c81935348be (Fix switching to a branch > with D/F when current branch has file D., 2007-03-15) we didn't > bother to free() before we called die(). > > But when this code was later libified in 203a2fe1170 (Allow callers > of unpack_trees() to handle failure, 2008-02-07) we started to leak > as we returned data to the caller. This fixes that memory leak, > which can be observed under SANITIZE=leak with e.g. the > "t1001-read-tree-m-2way.sh" test. > > * "struct dir_struct": We've leaked the dir_struct ever since this > code was added back in c81935348be. > > When that commit was written there wasn't an equivalent of > dir_clear(). Since it was added in 270be816049 (dir.c: provide > clear_directory() for reclaiming dir_struct memory, 2013-01-06) > we've omitted freeing the memory allocated here. > > This memory leak could also be observed under SANITIZE=leak and the > "t1001-read-tree-m-2way.sh" test. > > This makes all the test in "t1001-read-tree-m-2way.sh" pass under > "GIT_TEST_PASSING_SANITIZE_LEAK=true", we'd previously die in tests > 25, 26 & 28. > > Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> > --- > t/t1001-read-tree-m-2way.sh | 2 ++ > unpack-trees.c | 3 ++- > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/t/t1001-read-tree-m-2way.sh b/t/t1001-read-tree-m-2way.sh > index 1057a96b249..d1115528cb9 100755 > --- a/t/t1001-read-tree-m-2way.sh > +++ b/t/t1001-read-tree-m-2way.sh > @@ -20,6 +20,8 @@ In the test, these paths are used: > rezrov - in H, deleted in M > yomin - not in H or M > ' > + > +TEST_PASSES_SANITIZE_LEAK=true > . ./test-lib.sh > . "$TEST_DIRECTORY"/lib-read-tree.sh > > diff --git a/unpack-trees.c b/unpack-trees.c > index a7e1712d236..89ca95ce90b 100644 > --- a/unpack-trees.c > +++ b/unpack-trees.c > @@ -2156,9 +2156,10 @@ static int verify_clean_subdirectory(const struct cache_entry *ce, > if (o->dir) > d.exclude_per_dir = o->dir->exclude_per_dir; > i = read_directory(&d, o->src_index, pathbuf, namelen+1, NULL); > + dir_clear(&d); > + free(pathbuf); > if (i) > return add_rejected_path(o, ERROR_NOT_UPTODATE_DIR, ce->name); > - free(pathbuf); > return cnt; > } > > -- > 2.33.0.1441.gbbcdb4c3c66 Nicely explained; and nice clean patch.
diff --git a/t/t1001-read-tree-m-2way.sh b/t/t1001-read-tree-m-2way.sh index 1057a96b249..d1115528cb9 100755 --- a/t/t1001-read-tree-m-2way.sh +++ b/t/t1001-read-tree-m-2way.sh @@ -20,6 +20,8 @@ In the test, these paths are used: rezrov - in H, deleted in M yomin - not in H or M ' + +TEST_PASSES_SANITIZE_LEAK=true . ./test-lib.sh . "$TEST_DIRECTORY"/lib-read-tree.sh diff --git a/unpack-trees.c b/unpack-trees.c index a7e1712d236..89ca95ce90b 100644 --- a/unpack-trees.c +++ b/unpack-trees.c @@ -2156,9 +2156,10 @@ static int verify_clean_subdirectory(const struct cache_entry *ce, if (o->dir) d.exclude_per_dir = o->dir->exclude_per_dir; i = read_directory(&d, o->src_index, pathbuf, namelen+1, NULL); + dir_clear(&d); + free(pathbuf); if (i) return add_rejected_path(o, ERROR_NOT_UPTODATE_DIR, ce->name); - free(pathbuf); return cnt; }
Fix two different but related memory leaks in verify_clean_subdirectory(). We leaked both the "pathbuf" if read_directory() returned non-zero, and we never cleaned up our own "struct dir_struct" either. * "pathbuf": When the read_directory() call followed by the free(pathbuf) was added in c81935348be (Fix switching to a branch with D/F when current branch has file D., 2007-03-15) we didn't bother to free() before we called die(). But when this code was later libified in 203a2fe1170 (Allow callers of unpack_trees() to handle failure, 2008-02-07) we started to leak as we returned data to the caller. This fixes that memory leak, which can be observed under SANITIZE=leak with e.g. the "t1001-read-tree-m-2way.sh" test. * "struct dir_struct": We've leaked the dir_struct ever since this code was added back in c81935348be. When that commit was written there wasn't an equivalent of dir_clear(). Since it was added in 270be816049 (dir.c: provide clear_directory() for reclaiming dir_struct memory, 2013-01-06) we've omitted freeing the memory allocated here. This memory leak could also be observed under SANITIZE=leak and the "t1001-read-tree-m-2way.sh" test. This makes all the test in "t1001-read-tree-m-2way.sh" pass under "GIT_TEST_PASSING_SANITIZE_LEAK=true", we'd previously die in tests 25, 26 & 28. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> --- t/t1001-read-tree-m-2way.sh | 2 ++ unpack-trees.c | 3 ++- 2 files changed, 4 insertions(+), 1 deletion(-)