Re: [PATCH 0/2] authencesn: Refactor in-place decryption

[Scott Guo <scott_gzh@163.com>]

Another thought: even with this fix, Fragnesia should still funciton. It 
just block current PoCs which pass in the page cache in the position for 
auth data.

Avoid changing the auth part would not be enough because attacker would 
still be able to link a page cache page within the cryptlen part and 
override it with the 4 bytes from sequence number.

在 2026/5/15 18:41, Scott Guo 写道:
> BTW, this should fix the Fragnesia vulnerability.
> 
> 在 2026/5/15 16:36, scott_gzh@163.com 写道:
>> From: Scott GUO <scottzhguo@tencent.com>
>>
>> This patch set introduced the sglist_shift_{left,right} helper
>> and refactor the sequence number handling for authencesn
>> decryption. Avoiding write to the auth part of the sg list.
>>
>> Scott GUO (2):
>>    scatterlist: Introduce sglist_shift_{left,right} helpers
>>    authencesn: Refactor inplace-decryption with sglist shift helper
>>
>>   crypto/authencesn.c          | 38 ++++++-----------
>>   crypto/scatterwalk.c         | 79 ++++++++++++++++++++++++++++++++++++
>>   include/crypto/scatterwalk.h |  6 +++
>>   3 files changed, 97 insertions(+), 26 deletions(-)
>>