From: Eric Biggers ebiggers@google.com
stable inclusion from stable-5.10.63 commit 894a02236d0d20305556af4bfba3259f28c0b86b bugzilla: 182231 https://gitee.com/openeuler/kernel/issues/I4EFS1
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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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 ebiggers@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com
Signed-off-by: Chen Jun chenjun102@huawei.com --- 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 dd05af983092..a9457fed351e 100644 --- a/fs/ext4/symlink.c +++ b/fs/ext4/symlink.c @@ -52,10 +52,19 @@ 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 = { .get_link = ext4_encrypted_get_link, .setattr = ext4_setattr, - .getattr = ext4_getattr, + .getattr = ext4_encrypted_symlink_getattr, .listxattr = ext4_listxattr, };