On 30.04.21 18:25, Philippe Mathieu-Daudé wrote:
read_directory() keeps pointers to alloc'ed data in path ...:
743 static int read_directory(BDRVVVFATState* s, int mapping_index)
744 {
...
792 buffer = g_malloc(length);
...
828 /* create mapping for this file */
829 if(!is_dot && !is_dotdot && (S_ISDIR(st.st_mode) || st.st_size)) {
830 s->current_mapping = array_get_next(&(s->mapping));
...
847 s->current_mapping->path=buffer;
... but these pointers are never free'd.
“Never” is not quite right, they are freed in some places: Namely in
remove_mapping(), and in handle_renames_and_mkdirs().
Speaking of the latter, which does some commit_t handling – should those
paths also be freed? (i.e. the ones in commit_t, in s->commits)
Free them in vvfat_close(),
to fix (QEMU built with --enable-sanitizers):
Direct leak of 148 byte(s) in 6 object(s) allocated from:
#0 0x55d7a363773f in malloc (qemu-system-x86_64+0x1dab73f)
#1 0x7f55c6447958 in g_malloc (/lib64/libglib-2.0.so.0+0x58958)
#2 0x55d7a5e17679 in init_directories block/vvfat.c:962:16
#3 0x55d7a5e1251e in vvfat_open block/vvfat.c:1255:9
#4 0x55d7a5a5363f in bdrv_open_driver block.c:1526:15
#5 0x55d7a5a9d369 in bdrv_open_common block.c:1802:11
#6 0x55d7a5a609f1 in bdrv_open_inherit block.c:3444:11
#7 0x55d7a5a65411 in bdrv_open_child_bs block.c:3079:10
#8 0x55d7a5a60079 in bdrv_open_inherit block.c:3391:19
#9 0x55d7a5a65da3 in bdrv_open block.c:3537:12
#10 0x55d7a5b33f6a in blk_new_open block/block-backend.c:421:10
#11 0x55d7a5a0a33e in blockdev_init blockdev.c:610:15
#12 0x55d7a5a088e7 in drive_new blockdev.c:994:11
#13 0x55d7a51b10c4 in drive_init_func softmmu/vl.c:636:12
#14 0x55d7a620e148 in qemu_opts_foreach util/qemu-option.c:1167:14
#15 0x55d7a51b0e20 in configure_blockdev softmmu/vl.c:695:9
#16 0x55d7a51a70b5 in qemu_create_early_backends softmmu/vl.c:1895:5
#17 0x55d7a519bf87 in qemu_init softmmu/vl.c:3551:5
#18 0x55d7a366f619 in main softmmu/main.c:49:5
Fixes: a046433a161 ("Major overhaul of the virtual FAT driver for read/write
support")
Signed-off-by: Philippe Mathieu-Daudé
---
block/vvfat.c | 5 +
1 file changed, 5 insertions(+)
First:
Reviewed-by: Max Reitz
Second:
In commit_mappings(), there is this line:
next_mapping->path = mapping->path;
That looks strange. Should that be a g_strdup(), or am I missing the
place where only one of them can really exist?
But, well, all of the vvfat code is just strange to me.
diff --git a/block/vvfat.c b/block/vvfat.c
index 2cc21787600..c193a816646 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -3228,6 +3228,11 @@ static void vvfat_close(BlockDriverState *bs)
{
BDRVVVFATState *s = bs->opaque;
+for (unsigned j = 0; j < s->mapping.next; j++) {
+mapping_t *mapping = array_get(&(s->mapping), j);
+
+g_free(mapping->path);
+}
vvfat_close_current_file(s);
array_free(&(s->fat));
array_free(&(s->directory));
