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| author | Jason Gunthorpe <jgunthorpe@obsidianresearch.com> | 2015-08-04 23:13:32 (GMT) |
|---|---|---|
| committer | Doug Ledford <dledford@redhat.com> | 2015-08-29 02:54:48 (GMT) |
| commit | 7e967fd0b84a843b2475acc67a5a8df138c5f5c0 (patch) | |
| tree | 3b3fce60c75058d1d5ce891b6c1dc7efca549d6f /net | |
| parent | b8ac3112462900a55a45df8e6098c67a139d8c2d (diff) | |
| download | linux-7e967fd0b84a843b2475acc67a5a8df138c5f5c0.tar.xz | |
IB/ucma: Fix theoretical user triggered use-after-free
Something like this:
CPU A CPU B
Acked-by: Sean Hefty <sean.hefty@intel.com>
======================== ================================
ucma_destroy_id()
wait_for_completion()
.. anything
ucma_put_ctx()
complete()
.. continues ...
ucma_leave_multicast()
mutex_lock(mut)
atomic_inc(ctx->ref)
mutex_unlock(mut)
ucma_free_ctx()
ucma_cleanup_multicast()
mutex_lock(mut)
kfree(mc)
rdma_leave_multicast(mc->ctx->cm_id,..
Fix it by latching the ref at 0. Once it goes to 0 mc and ctx cannot
leave the mutex(mut) protection.
The other atomic_inc in ucma_get_ctx is OK because mutex(mut) protects
it from racing with ucma_destroy_id.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Acked-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'net')
0 files changed, 0 insertions, 0 deletions