Skip to content

Commit

Permalink
ext4: report correct st_size for encrypted symlinks
Browse files Browse the repository at this point in the history
The stat() family of syscalls report the wrong size for encrypted
symlinks, which has caused breakage in several userspace programs.

Fix this by calling fscrypt_symlink_getattr() after ext4_getattr() for
encrypted symlinks.  This function computes the correct size by reading
and decrypting the symlink target (if it's not already cached).

For more details, see the commit which added fscrypt_symlink_getattr().

Fixes: f348c25 ("ext4 crypto: add symlink encryption")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210702065350.209646-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
  • Loading branch information
Eric Biggers committed Jul 26, 2021
1 parent d187605 commit 8c4bca1
Showing 1 changed file with 11 additions and 1 deletion.
12 changes: 11 additions & 1 deletion fs/ext4/symlink.c
Original file line number Diff line number Diff line change
Expand Up @@ -52,10 +52,20 @@ static const char *ext4_encrypted_get_link(struct dentry *dentry,
return paddr;
}

static int ext4_encrypted_symlink_getattr(struct user_namespace *mnt_userns,
const struct path *path,
struct kstat *stat, u32 request_mask,
unsigned int query_flags)
{
ext4_getattr(mnt_userns, path, stat, request_mask, query_flags);

return fscrypt_symlink_getattr(path, stat);
}

const struct inode_operations ext4_encrypted_symlink_inode_operations = {
.get_link = ext4_encrypted_get_link,
.setattr = ext4_setattr,
.getattr = ext4_getattr,
.getattr = ext4_encrypted_symlink_getattr,
.listxattr = ext4_listxattr,
};

Expand Down

0 comments on commit 8c4bca1

Please sign in to comment.