Re: [PATCH] scsi: megaraid_sas: fix PRP list out-of-bounds write

On 7/1/26 13:09, Mira Limbeck wrote:
> We've seen some similar looking logs, but since they didn't mention
> `prp` at all, we haven't responded here before.

Thx for chiming in here.

> Instead we sent a mail
> to the linux-scsi list [0], but got no response so far.
> 
> In our case the issue was first introduced by commit:
> 9b8b84879d4a ("block: Increase BLK_DEF_MAX_SECTORS_CAP")

Any reason why you didn't CC the author and the committer of that
change? Even if the bug is in the driver that might have been a good
idea, but before doing that, let's do something else first:

> This is similar to an issue we previously reported with the mpt3sas
> driver [1].
> 
> At least for our tests and one of our users we can say with certainty
> that reducing the queue sectors back to the previous value fixed the
> issue. In our tests this was done manually, and for one of our users
> with their root on the disks, it was handled via udev rules.
> 
> echo 1280 > /sys/block/<dev>/queue/max_sectors_kb
You also in your [0] mentioned that 12da89e8844a ("block: open code
bio_add_page and fix handling of mismatching P2P ranges") fixed things
in v7.0. Make me wonder if that is the case for the others affected by
this. Hence:

Lukasz, Mats, Daniel, have you checked if 7.1 or 7.2-rc2 are still affected?

Ciao, Thorsten

> [0]
> https://lore.kernel.org/all/[email protected]/
> [1]
> https://lore.kernel.org/all/[email protected]/