ACK/Cmnt: [SRU][Focal, hwe-5.8][PATCH 0/2] CVE-2019-19449

[Tim Gardner]

Acked-by: Tim Gardner <tim.gardner at canonical.com>

Assuming focal/linux _and_ focal/linux-hwe-5.8 since both patches 
cherry-pick cleanly.

On 9/29/21 5:57 PM, Luke Nowakowski-Krijger wrote:
> [Impact]
> Mounting a crafted f2fs file system with a segment count in a section
> that is less than segs_per_sec causes out-of-boundary memory access
> during fs initalization.
> 
> [Test case]
> Reproduced bug with syzbot reproducer
> (https://syzkaller.appspot.com/x/repro.c?x=102fbac5900000)
> with slight modification to target a valid loop device.
> Confirmed that after the patches were applied the fs reports that there
> are malformed segments/sections and mounting the file system fails,
> which stops the initialization from continuing and preventing the
> out-of-boundary memory access.
> 
> [Potential regression]
> The patches add checks that are a superset of the previous checks, which
> might cause some filesystems that succeeded in mounting to now fail.
> 
> Chao Yu (1):
>    f2fs: fix to do sanity check on segment/section count
> 
> Wang Xiaojun (1):
>    f2fs: fix wrong total_sections check and fsmeta check
> 
>   fs/f2fs/segment.h |  1 +
>   fs/f2fs/super.c   | 14 ++++++++++----
>   2 files changed, 11 insertions(+), 4 deletions(-)
> 

-- 
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Tim Gardner
Canonical, Inc