From: Randall Huang <huangrandall@xxxxxxxxxx>
commit 688078e7f36c293dae25b338ddc9e0a2790f6e06 upstream.
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@xxxxxxxxxx>
Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
[bwh: Backported to 4.19: Use f2fs_msg() instead of f2fs_err()]
Signed-off-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/f2fs/xattr.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index 1dae74f7cccac..201e9da1692a4 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -538,8 +538,9 @@ 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;
@@ -549,6 +550,8 @@ 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);
@@ -556,6 +559,16 @@ 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_msg(dentry->d_sb, KERN_ERR,
+ "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;
--
2.20.1
