https://github.com/torvalds/linux
Revision 51246bfd189064079c54421507236fd2723b18f3 authored by Thomas Gleixner on 02 February 2010, 10:40:27 UTC, committed by Thomas Gleixner on 03 February 2010, 14:13:22 UTC
If the owner of a PI futex dies we fix up the pi_state and set pi_state->owner to NULL. When a malicious or just sloppy programmed user space application sets the futex value to 0 e.g. by calling pthread_mutex_init(), then the futex can be acquired again. A new waiter manages to enqueue itself on the pi_state w/o damage, but on unlock the kernel dereferences pi_state->owner and oopses. Prevent this by checking pi_state->owner in the unlock path. If pi_state->owner is not current we know that user space manipulated the futex value. Ignore the mess and return -EINVAL. This catches the above case and also the case where a task hijacks the futex by setting the tid value and then tries to unlock it. Reported-by: Jermome Marchand <jmarchan@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Darren Hart <dvhltc@us.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org>
1 parent 5ecb01c
Tip revision: 51246bfd189064079c54421507236fd2723b18f3 authored by Thomas Gleixner on 02 February 2010, 10:40:27 UTC
futex: Handle user space corruption gracefully
futex: Handle user space corruption gracefully
Tip revision: 51246bf
| File | Mode | Size |
|---|---|---|
| Documentation | ||
| arch | ||
| block | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .gitignore | -rw-r--r-- | 843 bytes |
| .mailmap | -rw-r--r-- | 3.9 KB |
| COPYING | -rw-r--r-- | 18.3 KB |
| CREDITS | -rw-r--r-- | 91.8 KB |
| Kbuild | -rw-r--r-- | 2.4 KB |
| MAINTAINERS | -rw-r--r-- | 160.2 KB |
| Makefile | -rw-r--r-- | 52.0 KB |
| README | -rw-r--r-- | 17.0 KB |
| REPORTING-BUGS | -rw-r--r-- | 3.3 KB |
Computing file changes ...
