diff options
| author | Li Wang <liwang@redhat.com> | 2016-11-15 17:19:01 +0800 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2016-12-07 17:44:38 -0500 |
| commit | 64d2ab32efe39354c29e1ecefea3769586026979 (patch) | |
| tree | 915c8f0ac6207ce09a15e6cad275cd3788401c19 | |
| parent | 450630975da9e7dffe540753e169dc4da5fe7c29 (diff) | |
vfs: fix put_compat_statfs64() does not handle errors
put_compat_statfs64() does NOT return -1 and setting errno to EOVERFLOW
when some variables(like: f_bsize) overflowed in the returned struct.
The reason is that the ubuf->f_blocks is __u64 type, it couldn't be
4bits as the judgement in put_comat_statfs64(). Here correct the
__u32 variables(in struct compat_statfs64) for comparison.
reproducer:
step1. mount hugetlbfs with two different pagesize on ppc64 arch.
$ hugeadm --pool-pages-max 16M:0
$ hugeadm --create-mount
$ mount | grep -i hugetlbfs
none on /var/lib/hugetlbfs/pagesize-16MB type hugetlbfs (rw,relatime,seclabel,pagesize=16777216)
none on /var/lib/hugetlbfs/pagesize-16GB type hugetlbfs (rw,relatime,seclabel,pagesize=17179869184)
step2. compile & run this C program.
$ cat statfs64_test.c
#define _LARGEFILE64_SOURCE
#include <stdio.h>
#include <sys/syscall.h>
#include <sys/statfs.h>
int main()
{
struct statfs64 sb;
int err;
err = syscall(SYS_statfs64, "/var/lib/hugetlbfs/pagesize-16GB", sizeof(sb), &sb);
if (err)
return -1;
printf("sizeof f_bsize = %d, f_bsize=%ld\n", sizeof(sb.f_bsize), sb.f_bsize);
return 0;
}
$ gcc -m32 statfs64_test.c
$ ./a.out
sizeof f_bsize = 4, f_bsize=0
Signed-off-by: Li Wang <liwang@redhat.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/compat.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/compat.c b/fs/compat.c index bd064a2c3550..543b48c29ac3 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -253,9 +253,9 @@ COMPAT_SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct compat_statfs __user *, static int put_compat_statfs64(struct compat_statfs64 __user *ubuf, struct kstatfs *kbuf) { - if (sizeof ubuf->f_blocks == 4) { - if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail | - kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL) + if (sizeof(ubuf->f_bsize) == 4) { + if ((kbuf->f_type | kbuf->f_bsize | kbuf->f_namelen | + kbuf->f_frsize | kbuf->f_flags) & 0xffffffff00000000ULL) return -EOVERFLOW; /* f_files and f_ffree may be -1; it's okay * to stuff that into 32 bits */ |