On Wed, Sep 26, 2018 at 01:43:54PM -0700, Steve Wise wrote:
commit 308aa2b8f7b7db3332a7d41099fd37851fb793b2 upstream
Once the qp has been flushed, it cannot be flushed again. The user qp flush logic wasn't enforcing it however. The bug can cause touch-after-free crashes like:
Unable to handle kernel paging request for data at address 0x000001ec Faulting instruction address: 0xc008000016069100 Oops: Kernel access of bad area, sig: 11 [#1] ... NIP [c008000016069100] flush_qp+0x80/0x480 [iw_cxgb4] LR [c00800001606cd6c] c4iw_modify_qp+0x71c/0x11d0 [iw_cxgb4] Call Trace: [c00800001606cd6c] c4iw_modify_qp+0x71c/0x11d0 [iw_cxgb4] [c00800001606e868] c4iw_ib_modify_qp+0x118/0x200 [iw_cxgb4] [c0080000119eae80] ib_security_modify_qp+0xd0/0x3d0 [ib_core] [c0080000119c4e24] ib_modify_qp+0xc4/0x2c0 [ib_core] [c008000011df0284] iwcm_modify_qp_err+0x44/0x70 [iw_cm] [c008000011df0fec] destroy_cm_id+0xcc/0x370 [iw_cm] [c008000011ed4358] rdma_destroy_id+0x3c8/0x520 [rdma_cm] [c0080000134b0540] ucma_close+0x90/0x1b0 [rdma_ucm] [c000000000444da4] __fput+0xe4/0x2f0
So fix flush_qp() to only flush the wq once.
Cc: stable@vger.kernel.org Signed-off-by: Steve Wise swise@opengridcomputing.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com
Conflicts: drivers/infiniband/hw/cxgb4/qp.c
This "conflicts:" lines are not needed. I'll go delete them, but please be more careful next time...
greg k-h