Michael J. Ruhl d757c60eca IB/rdmavt: Fix concurrency panics in QP post_send and modify to error ... The RC/UC code path can go through a software loopback. In this code path the receive side QP is manipulated. If two threads are working on the QP receive side (i.e. post_send, and modify_qp to an error state), QP information can be corrupted. (post_send via loopback) set r_sge loop update r_sge (modify_qp) take r_lock update r_sge <---- r_sge is now incorrect (post_send) update r_sge <---- crash, etc. ... This can lead to one of the two following crashes: BUG: unable to handle kernel NULL pointer dereference at (null) IP: hfi1_copy_sge+0xf1/0x2e0 [hfi1] PGD 8000001fe6a57067 PUD 1fd9e0c067 PMD 0 Call Trace: ruc_loopback+0x49b/0xbc0 [hfi1] hfi1_do_send+0x38e/0x3e0 [hfi1] _hfi1_do_send+0x1e/0x20 [hfi1] process_one_work+0x17f/0x440 worker_thread+0x126/0x3c0 kthread+0xd1/0xe0 ret_from_fork_nospec_begin+0x21/0x21 or: BUG: unable to handle kernel NULL pointer dereference at 0000000000000048 IP: rvt_clear_mr_refs+0x45/0x370 [rdmavt] PGD 80000006ae5eb067 PUD ef15d0067 PMD 0 Call Trace: rvt_error_qp+0xaa/0x240 [rdmavt] rvt_modify_qp+0x47f/0xaa0 [rdmavt] ib_security_modify_qp+0x8f/0x400 [ib_core] ib_modify_qp_with_udata+0x44/0x70 [ib_core] modify_qp.isra.23+0x1eb/0x2b0 [ib_uverbs] ib_uverbs_modify_qp+0xaa/0xf0 [ib_uverbs] ib_uverbs_write+0x272/0x430 [ib_uverbs] vfs_write+0xc0/0x1f0 SyS_write+0x7f/0xf0 system_call_fastpath+0x1c/0x21 Fix by using the appropriate locking on the receiving QP. Fixes: 1570346153 ("IB/{hfi1, qib, rdmavt}: Move ruc_loopback to rdmavt") Cc: <stable@vger.kernel.org> #v4.9+ Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>		2019-03-04 15:47:23 -04:00
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rdmavt	IB/rdmavt: Fix concurrency panics in QP post_send and modify to error	2019-03-04 15:47:23 -04:00
rxe	RDMA: Handle ucontext allocations by IB/core	2019-02-22 14:11:37 -07:00
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