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exfat: fix refcount leak in exfat_find 

Fix refcount leaks in `exfat_find` related to `exfat_get_dentry_set`.

Function `exfat_get_dentry_set` would increase the reference counter of
`es->bh` on success. Therefore, `exfat_put_dentry_set` must be called
after `exfat_get_dentry_set` to ensure refcount consistency. This patch
relocate two checks to avoid possible leaks.

Fixes: 82ebecdc74 ("exfat: fix improper check of dentry.stream.valid_size")
Fixes: 13940cef95 ("exfat: add a check for invalid data size")
Signed-off-by: Shuhao Fu <sfual@cse.ust.hk>
Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
pull/1354/merge
Shuhao Fu 2025-10-21 16:42:28 +08:00 committed by Namjae Jeon
parent d61f1cc5db
commit 9aee8de970
1 changed files with 10 additions and 10 deletions
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20
fs/exfat/namei.c
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@ -645,16 +645,6 @@ static int exfat_find(struct inode *dir, const struct qstr *qname,
info->valid_size = le64_to_cpu(ep2->dentry.stream.valid_size);
info->size = le64_to_cpu(ep2->dentry.stream.size);
if (info->valid_size < 0) {
exfat_fs_error(sb, "data valid size is invalid(%lld)", info->valid_size);
return -EIO;
}
if (unlikely(EXFAT_B_TO_CLU_ROUND_UP(info->size, sbi) > sbi->used_clusters)) {
exfat_fs_error(sb, "data size is invalid(%lld)", info->size);
return -EIO;
}
info->start_clu = le32_to_cpu(ep2->dentry.stream.start_clu);
if (!is_valid_cluster(sbi, info->start_clu) && info->size) {
exfat_warn(sb, "start_clu is invalid cluster(0x%x)",
@ -692,6 +682,16 @@ static int exfat_find(struct inode *dir, const struct qstr *qname,
0);
exfat_put_dentry_set(&es, false);
if (info->valid_size < 0) {
exfat_fs_error(sb, "data valid size is invalid(%lld)", info->valid_size);
return -EIO;
}
if (unlikely(EXFAT_B_TO_CLU_ROUND_UP(info->size, sbi) > sbi->used_clusters)) {
exfat_fs_error(sb, "data size is invalid(%lld)", info->size);
return -EIO;
}
if (ei->start_clu == EXFAT_FREE_CLUSTER) {
exfat_fs_error(sb,
"non-zero size file starts with zero cluster (size : %llu, p_dir : %u, entry : 0x%08x)",