From: Jaegeuk Kim jaegeuk@kernel.org
commit 4e240d1bab1ead280ddf5eb05058dba6bbd57d10 upstream.
If namelen is corrupted to have very long value, fill_dentries can copy wrong memory area.
Reviewed-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Ben Hutchings ben.hutchings@codethink.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/f2fs/dir.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
--- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -806,6 +806,17 @@ int f2fs_fill_dentries(struct dir_contex de_name.name = d->filename[bit_pos]; de_name.len = le16_to_cpu(de->name_len);
+ /* check memory boundary before moving forward */ + bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); + if (unlikely(bit_pos > d->max)) { + f2fs_msg(sbi->sb, KERN_WARNING, + "%s: corrupted namelen=%d, run fsck to fix.", + __func__, le16_to_cpu(de->name_len)); + set_sbi_flag(sbi, SBI_NEED_FSCK); + err = -EINVAL; + goto out; + } + if (f2fs_encrypted_inode(d->inode)) { int save_len = fstr->len;
@@ -826,7 +837,6 @@ int f2fs_fill_dentries(struct dir_contex if (sbi->readdir_ra == 1) f2fs_ra_node_page(sbi, le32_to_cpu(de->ino));
- bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); ctx->pos = start_pos + bit_pos; } out: