diff options
author | Al Viro <viro@zeniv.linux.org.uk> | 2012-02-13 05:56:29 +0400 |
---|---|---|
committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-02-14 05:45:39 +0400 |
commit | fcf83067bf6eb101a35620d752bd559d473cfbaa (patch) | |
tree | a34e89f84bea5bd9193ed12bc49361950bba03a8 | |
parent | dcdbed853d9fbb0547b781ba676049b87f54129a (diff) | |
download | linux-fcf83067bf6eb101a35620d752bd559d473cfbaa.tar.xz |
vfs: fix compat_sys_stat() handling of overflows in st_nlink
Massaged cp_compat_stat() into form closer to cp_new_stat(); the only
real issue had been in handling of st_nlink overflows - native 32bit
stat(2) returns -EOVERFLOW in such situations, compat one silently
loses upper bits.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r-- | fs/compat.c | 56 |
1 files changed, 25 insertions, 31 deletions
diff --git a/fs/compat.c b/fs/compat.c index fa9d721ecfee..07880bae28a9 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -131,41 +131,35 @@ asmlinkage long compat_sys_utimes(const char __user *filename, struct compat_tim static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf) { - compat_ino_t ino = stat->ino; - typeof(ubuf->st_uid) uid = 0; - typeof(ubuf->st_gid) gid = 0; - int err; + struct compat_stat tmp; - SET_UID(uid, stat->uid); - SET_GID(gid, stat->gid); + if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev)) + return -EOVERFLOW; - if ((u64) stat->size > MAX_NON_LFS || - !old_valid_dev(stat->dev) || - !old_valid_dev(stat->rdev)) + memset(&tmp, 0, sizeof(tmp)); + tmp.st_dev = old_encode_dev(stat->dev); + tmp.st_ino = stat->ino; + if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) return -EOVERFLOW; - if (sizeof(ino) < sizeof(stat->ino) && ino != stat->ino) + tmp.st_mode = stat->mode; + tmp.st_nlink = stat->nlink; + if (tmp.st_nlink != stat->nlink) return -EOVERFLOW; - - if (clear_user(ubuf, sizeof(*ubuf))) - return -EFAULT; - - err = __put_user(old_encode_dev(stat->dev), &ubuf->st_dev); - err |= __put_user(ino, &ubuf->st_ino); - err |= __put_user(stat->mode, &ubuf->st_mode); - err |= __put_user(stat->nlink, &ubuf->st_nlink); - err |= __put_user(uid, &ubuf->st_uid); - err |= __put_user(gid, &ubuf->st_gid); - err |= __put_user(old_encode_dev(stat->rdev), &ubuf->st_rdev); - err |= __put_user(stat->size, &ubuf->st_size); - err |= __put_user(stat->atime.tv_sec, &ubuf->st_atime); - err |= __put_user(stat->atime.tv_nsec, &ubuf->st_atime_nsec); - err |= __put_user(stat->mtime.tv_sec, &ubuf->st_mtime); - err |= __put_user(stat->mtime.tv_nsec, &ubuf->st_mtime_nsec); - err |= __put_user(stat->ctime.tv_sec, &ubuf->st_ctime); - err |= __put_user(stat->ctime.tv_nsec, &ubuf->st_ctime_nsec); - err |= __put_user(stat->blksize, &ubuf->st_blksize); - err |= __put_user(stat->blocks, &ubuf->st_blocks); - return err; + SET_UID(tmp.st_uid, stat->uid); + SET_GID(tmp.st_gid, stat->gid); + tmp.st_rdev = old_encode_dev(stat->rdev); + if ((u64) stat->size > MAX_NON_LFS) + return -EOVERFLOW; + tmp.st_size = stat->size; + tmp.st_atime = stat->atime.tv_sec; + tmp.st_atime_nsec = stat->atime.tv_nsec; + tmp.st_mtime = stat->mtime.tv_sec; + tmp.st_mtime_nsec = stat->mtime.tv_nsec; + tmp.st_ctime = stat->ctime.tv_sec; + tmp.st_ctime_nsec = stat->ctime.tv_nsec; + tmp.st_blocks = stat->blocks; + tmp.st_blksize = stat->blksize; + return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0; } asmlinkage long compat_sys_newstat(const char __user * filename, |