Bug#1036755: linux: 6.1.26 <= x < 6.1.30 breaks applications using mmap(MAP_32BIT)

[Salvatore Bonaccorso <carnil@debian.org>]

Control: tags -1 + confirmed pending

Hi Apollon,

On Thu, May 25, 2023 at 03:26:50PM +0300, Apollon Oikonomopoulos wrote:
> Source: linux
> Version: 6.1.27-1
> Severity: critical
> Tags: upstream
> Affects: ganeti
> Justification: breaks unrelated software
> 
> Dear Kernel Maintainers,
> 
> A regression was introduced with upstream commit 58c5d0d6d5,  
> subsequently backported to 6.1 as 7e6631f7 and released with 6.1.26.  
> These commits break MAP_32BIT and affect applications relying on it. In 
> particular, we are seeing failures in ganeti's autopkgtests[1], where a 
> daemon written in Haskell (the GHC linker uses MAP_32BIT) segfaults with 
> a null pointer dereference. From the build artifacts:
> 
>  ganeti-luxid: mmap 4096 bytes at (nil): Cannot allocate memory
>  ganeti-luxid: Try specifying an address with +RTS -xm<addr> -RTS
> 
> This has already been discussed on GHC's discourse[2] and has been fixed 
> upstream, with the fix queued for 6.1.30[3]. Please consider upgrading 
> to 6.1.30 or cherry-picking the fix for Bookworm.

I'm not yet certain, that critical severity is right, and making it
RC. But will look into the issue today.

Defitnively the issue will be fixed. Just at this stage for the
bookworm release I will pick it for the first upload after the release
in a point release update or a security update (whatever will come
first likely).

In any case I'm already preparing the 6.1.30 import for bookworm.

Regards,
Salvatore