dd08b84e35
ler@, markj@ reported a use after free in nfscl_cleanupkext().
They also provided two possible causes:
- In nfscl_cleanup_common(), "own" is the owner string
owp->nfsow_owner. If we free that particular
owner structure, than in subsequent comparisons
"own" will point to freed memory.
- nfscl_cleanup_common() can free more than one owner, so the use
of LIST_FOREACH_SAFE() in nfscl_cleanupkext() is not sufficient.
I also believe there is a 3rd:
- If nfscl_freeopenowner() or nfscl_freelockowner() is called
without the NFSCLSTATE mutex held, this could race with
nfscl_cleanupkext().
This could happen when the exclusive lock is held
on the client, such as when delegations are being returned.
This patch fixes them as follows:
1 - Copy the owner string to a local variable before the
nfscl_cleanup_common() call.
2 - Modify nfscl_cleanup_common() to return whether or not a
free was done.
When a free was done, do a goto to restart the loop, instead
of using FOREACH_SAFE, which was not safe in this case.
3 - Acquire the NFSCLSTATE mutex in nfscl_freeopenowner()
and nfscl_freelockowner(), if it not already held.
This serializes all of these calls with the ones done in
nfscl_cleanup_common().
Reported by: ler
Reviewed by: markj
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D34334
|
||
|---|---|---|
| .cirrus-ci | ||
| .github | ||
| bin | ||
| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| stand | ||
| sys | ||
| targets | ||
| tests | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| .arcconfig | ||
| .arclint | ||
| .cirrus.yml | ||
| .clang-format | ||
| .gitattributes | ||
| .gitignore | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| Makefile.libcompat | ||
| Makefile.sys.inc | ||
| ObsoleteFiles.inc | ||
| README.md | ||
| RELNOTES | ||
| UPDATING | ||
FreeBSD Source:
This is the top level of the FreeBSD source directory.
FreeBSD is an operating system used to power modern servers, desktops, and embedded platforms. A large community has continually developed it for more than thirty years. Its advanced networking, security, and storage features have made FreeBSD the platform of choice for many of the busiest web sites and most pervasive embedded networking and storage devices.
For copyright information, please see the file COPYRIGHT in this directory. Additional copyright information also exists for some sources in this tree - please see the specific source directories for more information.
The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree. See build(7), config(8), FreeBSD handbook on building userland, and Handbook for kernels for more information, including setting make(1) variables.
Source Roadmap:
| Directory | Description |
|---|---|
| bin | System/user commands. |
| cddl | Various commands and libraries under the Common Development and Distribution License. |
| contrib | Packages contributed by 3rd parties. |
| crypto | Cryptography stuff (see crypto/README). |
| etc | Template files for /etc. |
| gnu | Commands and libraries under the GNU General Public License (GPL) or Lesser General Public License (LGPL). Please see gnu/COPYING and gnu/COPYING.LIB for more information. |
| include | System include files. |
| kerberos5 | Kerberos5 (Heimdal) package. |
| lib | System libraries. |
| libexec | System daemons. |
| release | Release building Makefile & associated tools. |
| rescue | Build system for statically linked /rescue utilities. |
| sbin | System commands. |
| secure | Cryptographic libraries and commands. |
| share | Shared resources. |
| stand | Boot loader sources. |
| sys | Kernel sources. |
sys/arch/conf |
Kernel configuration files. GENERIC is the configuration used in release builds. NOTES contains documentation of all possible entries. |
| tests | Regression tests which can be run by Kyua. See tests/README for additional information. |
| tools | Utilities for regression testing and miscellaneous tasks. |
| usr.bin | User commands. |
| usr.sbin | System administration commands. |
For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see FreeBSD Handbook.