From 64d2ab32efe39354c29e1ecefea3769586026979 Mon Sep 17 00:00:00 2001 From: Li Wang Date: Tue, 15 Nov 2016 17:19:01 +0800 Subject: 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 #include #include 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 Reviewed-by: Andreas Dilger Signed-off-by: Al Viro --- fs/compat.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'fs/compat.c') 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 */ -- cgit v1.2.3-55-g7522