Fork of alistair23 Linux kernel for reMarkable from https://github.com/alistair23/linux
83b62687a0
The trace event "workqueue_queue_work" references an unsafe string in
dereferencing the name of the workqueue. As the name is allocated, it
could later be freed, and the pointer to that string could stay on the
tracing buffer. If the trace buffer is read after the string is freed, it
will reference an unsafe pointer.
I added a new verifier to make sure that all strings referenced in the
output of the trace buffer is safe to read and this triggered on the
workqueue_queue_work trace event:
workqueue_queue_work: work struct=00000000b2b235c7 function=gc_worker workqueue=(0xffff888100051160:events_power_efficient)[UNSAFE-MEMORY] req_cpu=256 cpu=1
workqueue_queue_work: work struct=00000000c344caec function=flush_to_ldisc workqueue=(0xffff888100054d60:events_unbound)[UNSAFE-MEMORY] req_cpu=256 cpu=4294967295
workqueue_queue_work: work struct=00000000b2b235c7 function=gc_worker workqueue=(0xffff888100051160:events_power_efficient)[UNSAFE-MEMORY] req_cpu=256 cpu=1
workqueue_queue_work: work struct=000000000b238b3f function=vmstat_update workqueue=(0xffff8881000c3760:mm_percpu_wq)[UNSAFE-MEMORY] req_cpu=1 cpu=1
Also, if this event is read via a user space application like perf or
trace-cmd, the name would only be an address and useless information:
workqueue_queue_work: work struct=0xffff953f80b4b918 function=disk_events_workfn workqueue=ffff953f8005d378 req_cpu=8192 cpu=5
Cc: Zqiang <qiang.zhang@windriver.com>
Cc: Tejun Heo <tj@kernel.org>
Fixes:
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||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.