Since the kernel's minimum gcc version is now 8.1, the workaround for a strange gcc bug in fscrypt_ioctl_set_policy() is no longer needed.
Signed-off-by: Eric Biggers <[email protected]> --- fs/crypto/policy.c | 17 ++--------------- 1 file changed, 2 insertions(+), 15 deletions(-) diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c index 9915e39362db..f40fb5924e75 100644 --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -505,36 +505,23 @@ static int set_encryption_policy(struct inode *inode, int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg) { union fscrypt_policy policy; union fscrypt_policy existing_policy; struct inode *inode = file_inode(filp); - u8 version; int size; int ret; if (get_user(policy.version, (const u8 __user *)arg)) return -EFAULT; size = fscrypt_policy_size(&policy); if (size <= 0) return -EINVAL; - /* - * We should just copy the remaining 'size - 1' bytes here, but a - * bizarre bug in gcc 7 and earlier (fixed by gcc r255731) causes gcc to - * think that size can be 0 here (despite the check above!) *and* that - * it's a compile-time constant. Thus it would think copy_from_user() - * is passed compile-time constant ULONG_MAX, causing the compile-time - * buffer overflow check to fail, breaking the build. This only occurred - * when building an i386 kernel with -Os and branch profiling enabled. - * - * Work around it by just copying the first byte again... - */ - version = policy.version; - if (copy_from_user(&policy, arg, size)) + if (copy_from_user((u8 *)&policy + 1, (const u8 __user *)arg + 1, + size - 1)) return -EFAULT; - policy.version = version; if (!inode_owner_or_capable(&nop_mnt_idmap, inode)) return -EACCES; ret = mnt_want_write_file(filp); base-commit: 83f1454877cc292b88baf13c829c16ce6937d120 -- 2.54.0
