Re: [PATCH AUTOSEL 5.3 169/203] x86/platform/uv: Fix kmalloc() NULL check routine

Sasha Levin
2019-10-01T16:06:05Z

On Sun, Sep 22, 2019 at 10:25:44PM +0200, Greg KH wrote:
>On Sun, Sep 22, 2019 at 02:43:15PM -0400, Sasha Levin wrote:
>> From: Austin Kim <austindh.kim@gmail.com>
>>
>> [ Upstream commit 864b23f0169d5bff677e8443a7a90dfd6b090afc ]
>>
>> The result of kmalloc() should have been checked ahead of below statement:
>>
>> pqp = (struct bau_pq_entry *)vp;
>>
>> Move BUG_ON(!vp) before above statement.
>>
>> Signed-off-by: Austin Kim <austindh.kim@gmail.com>
>> Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
>> Cc: Hedi Berriche <hedi.berriche@hpe.com>
>> Cc: Linus Torvalds <torvalds@linux-foundation.org>
>> Cc: Mike Travis <mike.travis@hpe.com>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: Russ Anderson <russ.anderson@hpe.com>
>> Cc: Steve Wahl <steve.wahl@hpe.com>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: allison@lohutok.net
>> Cc: andy@infradead.org
>> Cc: armijn@tjaldur.nl
>> Cc: bp@alien8.de
>> Cc: dvhart@infradead.org
>> Cc: gregkh@linuxfoundation.org
>> Cc: hpa@zytor.com
>> Cc: kjlu@umn.edu
>> Cc: platform-driver-x86@vger.kernel.org
>> Link: https://lkml.kernel.org/r/20190905232951.GA28779@LGEARND20B15
>> Signed-off-by: Ingo Molnar <mingo@kernel.org>
>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>> ---
>> arch/x86/platform/uv/tlb_uv.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c
>> index 20c389a91b803..5f0a96bf27a1f 100644
>> --- a/arch/x86/platform/uv/tlb_uv.c
>> +++ b/arch/x86/platform/uv/tlb_uv.c
>> @@ -1804,9 +1804,9 @@ static void pq_init(int node, int pnode)
>>
>> plsize = (DEST_Q_SIZE + 1) * sizeof(struct bau_pq_entry);
>> vp = kmalloc_node(plsize, GFP_KERNEL, node);
>> - pqp = (struct bau_pq_entry *)vp;
>> - BUG_ON(!pqp);
>> + BUG_ON(!vp);
>>
>> + pqp = (struct bau_pq_entry *)vp;
>> cp = (char *)pqp + 31;
>> pqp = (struct bau_pq_entry *)(((unsigned long)cp >> 5) << 5);
>>
>
>How did this even get merged in the first place? I thought a number of
>us complained about it.
>
>This isn't any change in code, and the original is just fine, the author
>didn't realize how C works :(
>
>Please drop this.

Heh, I've dropped it.

--
Thanks,
Sasha