f2fs: fix to avoid memory leakage in f2fs_listxattr

In f2fs_listxattr, there is no boundary check before
memcpy e_name to buffer.
If the e_name_len is corrupted,
unexpected memory contents may be returned to the buffer.

Signed-off-by: Randall Huang <huangrandall@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Randall Huang 2019-10-18 14:56:22 +08:00 committed by Jaegeuk Kim
parent 9f701f6c77
commit 688078e7f3

View File

@ -539,8 +539,9 @@ out:
ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
{
struct inode *inode = d_inode(dentry);
nid_t xnid = F2FS_I(inode)->i_xattr_nid;
struct f2fs_xattr_entry *entry;
void *base_addr;
void *base_addr, *last_base_addr;
int error = 0;
size_t rest = buffer_size;
@ -550,6 +551,8 @@ ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
if (error)
return error;
last_base_addr = (void *)base_addr + XATTR_SIZE(xnid, inode);
list_for_each_xattr(entry, base_addr) {
const struct xattr_handler *handler =
f2fs_xattr_handler(entry->e_name_index);
@ -557,6 +560,15 @@ ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
size_t prefix_len;
size_t size;
if ((void *)(entry) + sizeof(__u32) > last_base_addr ||
(void *)XATTR_NEXT_ENTRY(entry) > last_base_addr) {
f2fs_err(F2FS_I_SB(inode), "inode (%lu) has corrupted xattr",
inode->i_ino);
set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_FSCK);
error = -EFSCORRUPTED;
goto cleanup;
}
if (!handler || (handler->list && !handler->list(dentry)))
continue;