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| author | Colin Ian King <colin.king@canonical.com> | 2017-09-04 18:50:05 +0100 |
|---|---|---|
| committer | James Morris <james.l.morris@oracle.com> | 2017-10-19 13:09:33 +1100 |
| commit | 76ba89c76f2c74e208d93a9e7c698e39eeb3b85c (patch) | |
| tree | 94ee1504a73ca7d7c7545f3282210d5c2091068e | |
| parent | 494b9ae7abb84e6d88d7587906aff29dd26cf9d0 (diff) | |
| download | linux-76ba89c76f2c74e208d93a9e7c698e39eeb3b85c.tar.bz2 | |
commoncap: move assignment of fs_ns to avoid null pointer dereference
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>
Cc: stable@vger.kernel.org
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
| -rw-r--r-- | security/commoncap.c | 3 |
1 files changed, 2 insertions, 1 deletions
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) |