Kenneth Kasilag
1c590ed4b7
eip93_hmac_setkey() allocates a temporary ahash transform for
computing HMAC ipad/opad key material. The allocation uses the
driver-specific cra_driver_name (e.g. "sha256-eip93") but passes
CRYPTO_ALG_ASYNC as the mask, which excludes async algorithms.
Since the EIP93 hash algorithms are the only ones registered
under those driver names and they are inherently async, the
lookup is self-contradictory and always fails with -ENOENT.
When called from the AEAD setkey path, this failure leaves the
SA record partially initialized with zeroed digest fields. A
subsequent crypto operation then dereferences a NULL pointer in
the request context, resulting in a kernel panic:
```
pc : eip93_aead_handle_result+0xc8c/0x1240 [crypto_hw_eip93]
lr : eip93_aead_handle_result+0xbec/0x1240 [crypto_hw_eip93]
sp : ffffffc082feb820
x29: ffffffc082feb820 x28: ffffff8011043980 x27: 0000000000000000
x26: 0000000000000000 x25: ffffffc078da0bc8 x24: 0000000091043980
x23: ffffff8004d59e50 x22: ffffff8004d59410 x21: ffffff8004d593c0
x20: ffffff8004d593c0 x19: ffffff8004d4f300 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000007fda7aa498
x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: fffffffff8127a80 x9 : 0000000000000000
x8 : ffffff8004d4f380 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000040 x4 : 0000000000000008 x3 : 0000000000000009
x2 : 0000000000000008 x1 : 0000000028000003 x0 : ffffff8004d388c0
Code: 910142b6 f94012e0 f9002aa0 f90006d3 (f9400740)
```
The reported symbol eip93_aead_handle_result+0xc8c is a
resolution artifact from static functions being merged under
the nearest exported symbol. Decoding the faulting sequence:
```
910142b6 ADD X22, X21, #0x50
f94012e0 LDR X0, [X23, #0x20]
f9002aa0 STR X0, [X21, #0x50]
f90006d3 STR X19, [X22, #0x8]
f9400740 LDR X0, [X26, #0x8]
```
The faulting LDR at [X26, #0x8] is loading ctx->flags
(offset 8 in eip93_hash_ctx), where ctx has been resolved
to NULL from a partially initialized or unreachable
transform context following the failed setkey.
Fix this by dropping the CRYPTO_ALG_ASYNC mask from the
crypto_alloc_ahash() call. The code already handles async
completion correctly via crypto_wait_req(), so there is no
requirement to restrict the lookup to synchronous algorithms.
Note that hashing a single 64-byte block through the hardware
is likely slower than doing it in software due to the DMA
round-trip overhead, but offloading it may still spare CPU
cycles on the slower embedded cores where this IP is found.
Fixes: 9739f5f93b78 ("crypto: eip93 - Add Inside Secure SafeXcel EIP-93 crypto engine support")
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
[Detailed investigation report of this bug]
Signed-off-by: Kenneth Kasilag <kenneth@kasilag.me>
Link: https://github.com/openwrt/openwrt/pull/22886
Signed-off-by: Robert Marko <robimarko@gmail.com>
OpenWrt Project is a Linux operating system targeting embedded devices. Instead of trying to create a single, static firmware, OpenWrt provides a fully writable filesystem with package management. This frees you from the application selection and configuration provided by the vendor and allows you to customize the device through the use of packages to suit any application. For developers, OpenWrt is the framework to build an application without having to build a complete firmware around it; for users this means the ability for full customization, to use the device in ways never envisioned.
Sunshine!
Download
Built firmware images are available for many architectures and come with a package selection to be used as WiFi home router. To quickly find a factory image usable to migrate from a vendor stock firmware to OpenWrt, try the Firmware Selector.
If your device is supported, please follow the Info link to see install instructions or consult the support resources listed below.
An advanced user may require additional or specific package. (Toolchain, SDK, ...) For everything else than simple firmware download, try the wiki download page:
Development
To build your own firmware you need a GNU/Linux, BSD or macOS system (case sensitive filesystem required). Cygwin is unsupported because of the lack of a case sensitive file system.
Requirements
You need the following tools to compile OpenWrt, the package names vary between distributions. A complete list with distribution specific packages is found in the Build System Setup documentation.
binutils bzip2 diff find flex gawk gcc-6+ getopt grep install libc-dev libz-dev
make4.1+ perl python3.7+ rsync subversion unzip which
Quickstart
-
Run
./scripts/feeds update -ato obtain all the latest package definitions defined in feeds.conf / feeds.conf.default -
Run
./scripts/feeds install -ato install symlinks for all obtained packages into package/feeds/ -
Run
make menuconfigto select your preferred configuration for the toolchain, target system & firmware packages. -
Run
maketo build your firmware. This will download all sources, build the cross-compile toolchain and then cross-compile the GNU/Linux kernel & all chosen applications for your target system.
Related Repositories
The main repository uses multiple sub-repositories to manage packages of
different categories. All packages are installed via the OpenWrt package
manager called opkg. If you're looking to develop the web interface or port
packages to OpenWrt, please find the fitting repository below.
-
LuCI Web Interface: Modern and modular interface to control the device via a web browser.
-
OpenWrt Packages: Community repository of ported packages.
-
OpenWrt Routing: Packages specifically focused on (mesh) routing.
-
OpenWrt Video: Packages specifically focused on display servers and clients (Xorg and Wayland).
Support Information
For a list of supported devices see the OpenWrt Hardware Database
Documentation
Support Community
- Forum: For usage, projects, discussions and hardware advise.
- Support Chat: Channel
#openwrton oftc.net.
Developer Community
- Bug Reports: Report bugs in OpenWrt
- Dev Mailing List: Send patches
- Dev Chat: Channel
#openwrt-develon oftc.net.
License
OpenWrt is licensed under GPL-2.0