lkml.org 
[lkml]   [2019]   [Dec]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [tip: core/urgent] rseq: Reject unknown flags on rseq unregister
----- On Dec 25, 2019, at 6:39 AM, Borislav Petkov bp@alien8.de wrote:

> On Wed, Dec 25, 2019 at 10:38:53AM -0000, tip-bot2 for Mathieu Desnoyers wrote:
>> The following commit has been merged into the core/urgent branch of tip:
>>
>> Commit-ID: 66528a4575eee9f5a5270219894ab6178f146e84
>> Gitweb:
>> https://git.kernel.org/tip/66528a4575eee9f5a5270219894ab6178f146e84
>> Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
>> AuthorDate: Wed, 11 Dec 2019 11:17:11 -05:00
>> Committer: Ingo Molnar <mingo@kernel.org>
>> CommitterDate: Wed, 25 Dec 2019 10:41:20 +01:00
>>
>> rseq: Reject unknown flags on rseq unregister
>>
>> It is preferrable to reject unknown flags within rseq unregistration
>> rather than to ignore them. It is an oversight caused by the fact that
>> the check for unknown flags is after the rseq unregister flag check.
>>
>> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
>> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
>> Cc: Linus Torvalds <torvalds@linux-foundation.org>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Link:
>> https://lkml.kernel.org/r/20191211161713.4490-2-mathieu.desnoyers@efficios.com
>> Signed-off-by: Ingo Molnar <mingo@kernel.org>
>> ---
>> kernel/rseq.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/kernel/rseq.c b/kernel/rseq.c
>> index 27c48eb..a4f86a9 100644
>> --- a/kernel/rseq.c
>> +++ b/kernel/rseq.c
>> @@ -310,6 +310,8 @@ SYSCALL_DEFINE4(rseq, struct rseq __user *, rseq, u32,
>> rseq_len,
>> int ret;
>>
>> if (flags & RSEQ_FLAG_UNREGISTER) {
>> + if (flags & ~RSEQ_FLAG_UNREGISTER)
>> + return -EINVAL;
>> /* Unregister rseq for current thread. */
>> if (current->rseq != rseq || !current->rseq)
>> return -EINVAL;
>
> Cc: stable perhaps?

This could indeed be a candidate for stable, even though it's just a stricter
checking of unknown flags (returning an error rather than ignoring them).

Adding stable in CC here.

Thanks,

Mathieu


--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
\
 
 \ /
  Last update: 2019-12-26 23:32    [W:0.049 / U:12.776 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site