diff options
author | Lee Schermerhorn <Lee.Schermerhorn@hp.com> | 2007-07-15 23:40:54 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-16 09:05:46 -0700 |
commit | b4c07bce796833401317519e44075889c5fd4d5f (patch) | |
tree | 569448b0cc6e0eb1516e38c98bc770ad73308880 /fs/super.c | |
parent | e73a75fa7f062b52d015f1c961685dcaac57f710 (diff) | |
download | linux-b4c07bce796833401317519e44075889c5fd4d5f.tar.bz2 |
hugetlbfs: handle empty options string
I was seeing a null pointer deref in fs/super.c:vfs_kern_mount().
Some file system get_sb() handler was returning NULL mnt_sb with
a non-negative return value. I also noticed a "hugetlbfs: Bad
mount option:" message in the log.
Turns out that hugetlbfs_parse_options() was not checking for an
empty option string after call to strsep(). On failure,
hugetlbfs_parse_options() returns 1. hugetlbfs_fill_super() just
passed this return code back up the call stack where
vfs_kern_mount() missed the error and proceeded with a NULL mnt_sb.
Apparently introduced by patch:
hugetlbfs-use-lib-parser-fix-docs.patch
The problem was exposed by this line in my fstab:
none /huge hugetlbfs defaults 0 0
It can also be demonstrated by invoking mount of hugetlbfs
directly with no options or a bogus option.
This patch:
1) adds the check for empty option to hugetlbfs_parse_options(),
2) enhances the error message to bracket any unrecognized
option with quotes ,
3) modifies hugetlbfs_parse_options() to return -EINVAL on any
unrecognized option,
4) adds a BUG_ON() to vfs_kern_mount() to catch any get_sb()
handler that returns a NULL mnt->mnt_sb with a return value
>= 0.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/super.c')
-rw-r--r-- | fs/super.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/super.c b/fs/super.c index 5260d620c555..fc8ebedc6bed 100644 --- a/fs/super.c +++ b/fs/super.c @@ -884,6 +884,7 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void error = type->get_sb(type, flags, name, data, mnt); if (error < 0) goto out_free_secdata; + BUG_ON(!mnt->mnt_sb); error = security_sb_kern_mount(mnt->mnt_sb, secdata); if (error) |