On Thu, Mar 01, 2018 at 02:00:28PM -0800, Bart Van Assche wrote:
> This patch fixes the following KASAN complaint:
>
> ==================================================================
> BUG: KASAN: stack-out-of-bounds in rxe_post_send+0x77d/0x9b0 [rdma_rxe]
> Read of size 8 at addr ffff880061aef860 by task 01/1080
>
> CPU: 2 PID: 1080 Comm: 01 Not tainted 4.16.0-rc3-dbg+ #2
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
> Call Trace:
> dump_stack+0x85/0xc7
> print_address_description+0x65/0x270
> kasan_report+0x231/0x350
> rxe_post_send+0x77d/0x9b0 [rdma_rxe]
> __ib_drain_sq+0x1ad/0x250 [ib_core]
> ib_drain_qp+0x9/0x30 [ib_core]
> srp_destroy_qp+0x51/0x70 [ib_srp]
> srp_free_ch_ib+0xfc/0x380 [ib_srp]
> srp_create_target+0x1071/0x19e0 [ib_srp]
> kernfs_fop_write+0x180/0x210
> __vfs_write+0xb1/0x2e0
> vfs_write+0xf6/0x250
> SyS_write+0x99/0x110
> do_syscall_64+0xee/0x2b0
> entry_SYSCALL_64_after_hwframe+0x42/0xb7
>
> The buggy address belongs to the page:
> page:ffffea000186bbc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
> flags: 0x4000000000000000()
> raw: 4000000000000000 0000000000000000 0000000000000000 00000000ffffffff
> raw: 0000000000000000 ffffea000186bbe0 0000000000000000 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
> ffff880061aef700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ffff880061aef780: 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00
> >ffff880061aef800: f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 f2 f2 f2 f2
> ^
> ffff880061aef880: f2 f2 f2 00 00 00 00 00 00 00 00 00 00 00 f2 f2
> ffff880061aef900: f2 f2 f2 00 00 00 00 00 00 00 00 00 00 00 00 00
> ==================================================================
>
> Fixes: 765d67748bcf ("IB: new common API for draining queues")
> Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
> Cc: Steve Wise <swise@xxxxxxxxxxxxxxxxxxxxx>
> Cc: Sagi Grimberg <sagi@xxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> drivers/infiniband/core/verbs.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c
> index 2c7b0ceb46e6..4e2b231b03f7 100644
> +++ b/drivers/infiniband/core/verbs.c
> @@ -2194,7 +2194,13 @@ static void __ib_drain_sq(struct ib_qp *qp)
> struct ib_cq *cq = qp->send_cq;
> struct ib_qp_attr attr = { .qp_state = IB_QPS_ERR };
> struct ib_drain_cqe sdrain;
> - struct ib_send_wr swr = {}, *bad_swr;
> + struct ib_send_wr *bad_swr;
> + struct ib_rdma_wr swr = {
> + .wr = {
> + .opcode = IB_WR_RDMA_WRITE,
> + .wr_cqe = &sdrain.cqe,
> + },
> + };
I don't get it..
Since when did ib_post_send() start requiring a ib_rdma_wr?
IB_WR_RDMA_WRITE == 0, so even missing that is 'OK' but ugly.
What is the actual bug here?
Jason