Re: [PATCH for-rc] RDMA/qedr: Fix kernel panic when trying to access recv_cq

From: Jason Gunthorpe <jgg@nvidia.com>
To: Kamal Heib <kamalheib1@gmail.com>
Cc: linux-rdma@vger.kernel.org,
	Michal Kalderon <mkalderon@marvell.com>,
	Ariel Elior <aelior@marvell.com>
Subject: Re: [PATCH for-rc] RDMA/qedr: Fix kernel panic when trying to access recv_cq
Date: Wed, 7 Apr 2021 20:29:13 -0300	[thread overview]
Message-ID: <20210407232913.GA601885@nvidia.com> (raw)
In-Reply-To: <20210404125501.154789-1-kamalheib1@gmail.com>

On Sun, Apr 04, 2021 at 03:55:01PM +0300, Kamal Heib wrote:
> As INI QP does not require a recv_cq, avoid the following null pointer
> dereference by checking if the qp_type is not INI before trying to
> extract the recv_cq.
> 
> BUG: kernel NULL pointer dereference, address: 00000000000000e0
>  #PF: supervisor read access in kernel mode
>  #PF: error_code(0x0000) - not-present page
>  PGD 0 P4D 0
>  Oops: 0000 [#1] SMP PTI
>  CPU: 0 PID: 54250 Comm: mpitests-IMB-MP Not tainted 5.12.0-rc5 #1
>  Hardware name: Dell Inc. PowerEdge R320/0KM5PX, BIOS 2.7.0 08/19/2019
>  RIP: 0010:qedr_create_qp+0x378/0x820 [qedr]
>  Code: 02 00 00 50 e8 29 d4 a9 d1 48 83 c4 18 e9 65 fe ff ff 48 8b 53 10 48 8b 43 18 44 8b 82 e0 00 00 00 45 85 c0 0f 84 10 74 00 00 <8b> b8 e0 00 00 00 85 ff 0f 85 50 fd ff ff e9 fd 73 00 00 48 8d bd
>  RSP: 0018:ffff9c8f056f7a70 EFLAGS: 00010202
>  RAX: 0000000000000000 RBX: ffff9c8f056f7b58 RCX: 0000000000000009
>  RDX: ffff8c41a9744c00 RSI: ffff9c8f056f7b58 RDI: ffff8c41c0dfa280
>  RBP: ffff8c41c0dfa280 R08: 0000000000000002 R09: 0000000000000001
>  R10: 0000000000000000 R11: ffff8c41e06fc608 R12: ffff8c4194052000
>  R13: 0000000000000000 R14: ffff8c4191546070 R15: ffff8c41c0dfa280
>  FS:  00007f78b2787b80(0000) GS:ffff8c43a3200000(0000) knlGS:0000000000000000
>  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>  CR2: 00000000000000e0 CR3: 00000001011d6002 CR4: 00000000001706f0
>  Call Trace:
>   ib_uverbs_handler_UVERBS_METHOD_QP_CREATE+0x4e4/0xb90 [ib_uverbs]
>   ? ib_uverbs_cq_event_handler+0x30/0x30 [ib_uverbs]
>   ib_uverbs_run_method+0x6f6/0x7a0 [ib_uverbs]
>   ? ib_uverbs_handler_UVERBS_METHOD_QP_DESTROY+0x70/0x70 [ib_uverbs]
>   ? __cond_resched+0x15/0x30
>   ? __kmalloc+0x5a/0x440
>   ib_uverbs_cmd_verbs+0x195/0x360 [ib_uverbs]
>   ? xa_load+0x6e/0x90
>   ? cred_has_capability+0x7c/0x130
>   ? avc_has_extended_perms+0x17f/0x440
>   ? vma_link+0xae/0xb0
>   ? vma_set_page_prot+0x2a/0x60
>   ? mmap_region+0x298/0x6c0
>   ? do_mmap+0x373/0x520
>   ? selinux_file_ioctl+0x17f/0x220
>   ib_uverbs_ioctl+0xa7/0x110 [ib_uverbs]
>   __x64_sys_ioctl+0x84/0xc0
>   do_syscall_64+0x33/0x40
>   entry_SYSCALL_64_after_hwframe+0x44/0xae
>  RIP: 0033:0x7f78b120262b
> 
> Fixes: 06e8d1df46ed ("RDMA/qedr: Add support for user mode XRC-SRQ's")
> Signed-off-by: Kamal Heib <kamalheib1@gmail.com>
> ---
>  drivers/infiniband/hw/qedr/verbs.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Applied to for-rc, thanks

Jason