Messages in this thread | | | Date | Wed, 24 Oct 2001 17:35:33 +0200 | From | Jan Kara <> | Subject | Re: Overriding qouta limits in Linux kernel |
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Hello,
> Almost any suid binary may be used to create large files overriding quota > limits. Yes.
> When setuid-root binary inherits file descriptors from user process it may > write to it without respecting the quota restrictions. This is because > suid process has CAP_SYS_RESOURCE effective capability enabled during > writing to the file. Quota does not know anything about who opened file > descriptor and checks current process privileges only. This is bug in > kernel and not in those setuid-root binaries. Actually I think this is not a bug, it's a feature... If some process has a CAP_SYS_RESOURCE capability then it can override the limits (that's how I understand this capability). Hence it's got right to exceed user quota. I think this is reasonable behaviour (root can do anything - suid binaries are just making the will of root ;)). And BTW I know about no way how to know who opened the file...
Honza -- Jan Kara <jack@suse.cz> SuSE CR Labs - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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