[SRU][B][PATCH 0/2] CVE-2019-19449

[Luke Nowakowski-Krijger]

[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. 

[Backports]
Changed f2fs_info to f2fs_msg due to the fact that the f2fs_info
infastructure is not present and would require backporting many patches
to implement.

[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.

Luke Nowakowski-Krijger (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   | 15 +++++++++++----
 2 files changed, 12 insertions(+), 4 deletions(-)

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2.30.2