Messages in this thread | | | Date | Mon, 4 Sep 2017 13:53:39 -0500 | From | "Serge E. Hallyn" <> | Subject | Re: [PATCH][capabilities-next] commoncap: move assignment of fs_ns to avoid null pointer dereference |
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On Mon, Sep 04, 2017 at 06:50:05PM +0100, Colin King wrote: > From: Colin Ian King <colin.king@canonical.com> > > The pointer fs_ns is assigned from inode->i_ib->s_user_ns before > a null pointer check on inode, hence if inode is actually null we > will get a null pointer dereference on this assignment. Fix this > by only dereferencing inode after the null pointer check on > inode. > > Detected by CoverityScan CID#1455328 ("Dereference before null check") > > Fixes: 8db6c34f1dbc ("Introduce v3 namespaced file capabilities") > Signed-off-by: Colin Ian King <colin.king@canonical.com>
thanks!
Acked-by: Serge Hallyn <serge@hallyn.com>
> --- > security/commoncap.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/security/commoncap.c b/security/commoncap.c > index c25e0d27537f..fc46f5b85251 100644 > --- a/security/commoncap.c > +++ b/security/commoncap.c > @@ -585,13 +585,14 @@ int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data > struct vfs_ns_cap_data data, *nscaps = &data; > struct vfs_cap_data *caps = (struct vfs_cap_data *) &data; > kuid_t rootkuid; > - struct user_namespace *fs_ns = inode->i_sb->s_user_ns; > + struct user_namespace *fs_ns; > > memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data)); > > if (!inode) > return -ENODATA; > > + fs_ns = inode->i_sb->s_user_ns; > size = __vfs_getxattr((struct dentry *)dentry, inode, > XATTR_NAME_CAPS, &data, XATTR_CAPS_SZ); > if (size == -ENODATA || size == -EOPNOTSUPP) > -- > 2.14.1
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