From: John Ogness <john.ogness@linutronix.de>
To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Petr Mladek <mladek.petr@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Linux-Next Mailing List <linux-next@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
open list <linux-kernel@vger.kernel.org>,
lkft-triage@lists.linaro.org, LTP List <ltp@lists.linux.it>,
Andrew Morton <akpm@linux-foundation.org>,
Mike Rapoport <rppt@linux.ibm.com>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Rasmus Villemoes <rasmus.villemoes@prevas.dk>,
Linus Torvalds <torvalds@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Naresh Kamboju <naresh.kamboju@linaro.org>
Subject: Re: [PATCH] printk: ringbuffer: Wrong data pointer when appending small string
Date: Thu, 15 Oct 2020 12:05:42 +0206 [thread overview]
Message-ID: <875z7bhks1.fsf@jogness.linutronix.de> (raw)
In-Reply-To: <20201015063137.GA3668@jagdpanzerIV.localdomain>
On 2020-10-15, Sergey Senozhatsky <sergey.senozhatsky@gmail.com> wrote:
>> diff --git a/kernel/printk/printk_ringbuffer.c b/kernel/printk/printk_ringbuffer.c
>> index 2493348a1631..24a960a89aa8 100644
>> --- a/kernel/printk/printk_ringbuffer.c
>> +++ b/kernel/printk/printk_ringbuffer.c
>> @@ -1125,7 +1125,10 @@ static char *data_realloc(struct printk_ringbuffer *rb,
>>
>> /* If the data block does not increase, there is nothing to do. */
>> if (head_lpos - next_lpos < DATA_SIZE(data_ring)) {
>> - blk = to_block(data_ring, blk_lpos->begin);
>> + if (wrapped)
>> + blk = to_block(data_ring, 0);
>> + else
>> + blk = to_block(data_ring, blk_lpos->begin);
>> return &blk->data[0];
>> }
>
> Great catch.
Indeed. I don't know how we missed that one. :-/
Reviewed-by: John Ogness <john.ogness@linutronix.de>
next prev parent reply other threads:[~2020-10-15 9:59 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-14 10:49 BUG: KASAN: global-out-of-bounds in vprintk_store on x86_64 Naresh Kamboju
2020-10-14 12:47 ` Sergey Senozhatsky
2020-10-14 14:05 ` Petr Mladek
2020-10-14 15:13 ` Petr Mladek
2020-10-14 17:50 ` [PATCH] printk: ringbuffer: Wrong data pointer when appending small string Petr Mladek
2020-10-15 6:31 ` Sergey Senozhatsky
2020-10-15 9:59 ` John Ogness [this message]
2020-10-15 12:22 ` Petr Mladek
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