| Message ID | patch-08.10-32acc5e5c9e-20211004T002226Z-avarab@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | unpack-trees & dir APIs: fix memory leaks | expand |
On Sun, Oct 3, 2021 at 5:46 PM 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. > > Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> > --- > unpack-trees.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/unpack-trees.c b/unpack-trees.c > index bea598c9ece..260e7ec5bb4 100644 > --- a/unpack-trees.c > +++ b/unpack-trees.c > @@ -2138,9 +2138,10 @@ static int verify_clean_subdirectory(const struct cache_entry *ce, > > 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; > } > > -- > 2.33.0.1404.g83021034c5d Good catches, and nicely explained.
diff --git a/unpack-trees.c b/unpack-trees.c index bea598c9ece..260e7ec5bb4 100644 --- a/unpack-trees.c +++ b/unpack-trees.c @@ -2138,9 +2138,10 @@ static int verify_clean_subdirectory(const struct cache_entry *ce, 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. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> --- unpack-trees.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)