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authorLi Wang <liwang@redhat.com>2016-11-15 17:19:01 +0800
committerAl Viro <viro@zeniv.linux.org.uk>2016-12-07 17:44:38 -0500
commit64d2ab32efe39354c29e1ecefea3769586026979 (patch)
tree915c8f0ac6207ce09a15e6cad275cd3788401c19 /fs
parent450630975da9e7dffe540753e169dc4da5fe7c29 (diff)
downloadlinux-64d2ab32efe39354c29e1ecefea3769586026979.tar.bz2
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>
Diffstat (limited to 'fs')
-rw-r--r--fs/compat.c6
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 */