Messages in this thread | | | From | Roberto Sassu <> | Subject | RE: [PATCH v3 2/3] ima: Return int in the functions to measure a buffer | Date | Tue, 20 Jul 2021 12:38:43 +0000 |
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> From: Mimi Zohar [mailto:zohar@linux.ibm.com] > Sent: Monday, July 19, 2021 10:28 PM > Hi Roberto, > > On Mon, 2021-07-05 at 11:09 +0200, Roberto Sassu wrote: > > ima_measure_critical_data() and process_buffer_measurement() currently > > don't return a result. A caller wouldn't be able to know whether those > > functions were executed successfully. > > Missing is an explanation as to why these functions aren't currently > returning a result. The LSM/IMA hooks only return a negative result > for failure to appraise a file's integrity, not measure a file. Only > failure to appraise a file's integrity results in preventing the file > from being read/executed/mmaped. Other failures are only audited.
Hi Mimi
ok, will add it.
> > This patch modifies the return type from void to int, and returns 0 if the > > buffer has been successfully measured, a negative value otherwise. > > Needed here is an explanation as to why ima_measure_critical_data() is > special.
We don't want to unnecessarily calculate the digest twice.
> > Also, this patch does not modify the behavior of existing callers by > > processing the returned value. For those, the return value is ignored. > > I agree that the existing behavior shouldn't change, but will this > result in the bots complaining?
If I remember correctly, I didn't get any error even with W=1.
Thanks
Roberto
HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063 Managing Director: Li Peng, Li Jian, Shi Yanli
> thanks, > > Mimi
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