exec: delay address limit change until point of no return
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This should be continuation of http://lkml.org/lkml/2011/7/27/488
Quoted 5 lines · Andi Kleen
Quoted 4 lines · halfdog
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Hello Mr. Kleen,
Quoted 7 lines
Quoted 4 lines
I saw your posting on lkml. Currently, I have no deep enough understanding of kernel memory management, so do you think, that delaying could make a otherwise irrelevant timerace in exec arg handling somehow problematic?
I guess it would be better to fix it. Can you post your analysis to [email protected] ? Feel free to cc me.
Please see
https://bugzilla.kernel.org/show_bug.cgi?id=39222
for analysis (Timerace in sys_execve when copying argv/env data from userspace)
Seems to be historic, but not critical timerace (POC available, but no crash, mem-leaks, ..).
- From my opinion, it should be possible to make the argv ptr go over the 0xc0000000 kernel/user split on x86 architectures, but I do not know if the patch in discussion would worsen the situation. Until now, I failed to trouble the kernel using this.
- --
http://www.halfdog.net/
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