4.14-stable review patch. If anyone has any objections, please let me know.
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From: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp
commit 1f5781725dcbb026438e77091c91a94f678c3522 upstream.
syzbot is reporting NULL pointer dereference at xattr_getsecurity() [1], for cap_inode_getsecurity() is returning sizeof(struct vfs_cap_data) when memory allocation failed. Return -ENOMEM if memory allocation failed.
[1] https://syzkaller.appspot.com/bug?id=a55ba438506fe68649a5f50d2d82d56b365e010...
Signed-off-by: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Fixes: 8db6c34f1dbc8e06 ("Introduce v3 namespaced file capabilities") Reported-by: syzbot syzbot+9369930ca44f29e60e2d@syzkaller.appspotmail.com Cc: stable stable@vger.kernel.org # 4.14+ Acked-by: Serge E. Hallyn serge@hallyn.com Acked-by: James Morris james.morris@microsoft.com Signed-off-by: Eric W. Biederman ebiederm@xmission.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- security/commoncap.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/security/commoncap.c +++ b/security/commoncap.c @@ -449,6 +449,8 @@ int cap_inode_getsecurity(struct inode * magic |= VFS_CAP_FLAGS_EFFECTIVE; memcpy(&cap->data, &nscap->data, sizeof(__le32) * 2 * VFS_CAP_U32); cap->magic_etc = cpu_to_le32(magic); + } else { + size = -ENOMEM; } } kfree(tmpbuf);