From f99cbf2880f8968e67e56228c79bd76fe94c7d7b Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Wed, 1 Sep 2021 09:27:19 -0700 Subject: [PATCH] ext4: report correct st_size for encrypted symlinks commit 8c4bca10ceafc43b1ca0a9fab5fa27e13cbce99e upstream. 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: f348c252320b ("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 Signed-off-by: Greg Kroah-Hartman --- fs/ext4/symlink.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c index 75f250850d5d..baaee1b993a4 100644 --- a/fs/ext4/symlink.c +++ b/fs/ext4/symlink.c @@ -55,6 +55,15 @@ static const char *ext4_encrypted_get_link(struct dentry *dentry, return paddr; } +static int ext4_encrypted_symlink_getattr(const struct path *path, + struct kstat *stat, u32 request_mask, + unsigned int query_flags) +{ + ext4_getattr(path, stat, request_mask, query_flags); + + return fscrypt_symlink_getattr(path, stat); +} + const struct inode_operations ext4_encrypted_symlink_inode_operations = { #ifdef MY_ABC_HERE .syno_getattr = ext4_syno_getattr, @@ -68,7 +77,7 @@ const struct inode_operations ext4_encrypted_symlink_inode_operations = { #endif /* MY_ABC_HERE */ .get_link = ext4_encrypted_get_link, .setattr = ext4_setattr, - .getattr = ext4_getattr, + .getattr = ext4_encrypted_symlink_getattr, .listxattr = ext4_listxattr, #ifdef MY_ABC_HERE .syno_get_crtime = ext4_syno_get_crtime,