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0256b0aa80
There are a few bugs in the error handling for security_load_policy().
1) If the newpolicy->sidtab allocation fails then it leads to a NULL
dereference. Also the error code was not set to -ENOMEM on that
path.
2) If policydb_read() failed then we call policydb_destroy() twice
which meands we call kvfree(p->sym_val_to_name[i]) twice.
3) If policydb_load_isids() failed then we call sidtab_destroy() twice
and that results in a double free in the sidtab_destroy_tree()
function because entry.ptr_inner and entry.ptr_leaf are not set to
NULL.
One thing that makes this code nice to deal with is that none of the
functions return partially allocated data. In other words, the
policydb_read() either allocates everything successfully or it frees
all the data it allocates. It never returns a mix of allocated and
not allocated data.
I re-wrote this to only free the successfully allocated data which
avoids the double frees. I also re-ordered selinux_policy_free() so
it's in the reverse order of the allocation function.
Fixes: c7c556f1e8 ("selinux: refactor changing booleans")
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[PM: partially merged by hand due to merge fuzz]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.