4.4-stable review patch. If anyone has any objections, please let me know.
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From: Leon Romanovsky leonro@mellanox.com
commit ed65a4dc22083e73bac599ded6a262318cad7baf upstream.
The error in ucma_create_id() left ctx in the list of contexts belong to ucma file descriptor. The attempt to close this file descriptor causes to use-after-free accesses while iterating over such list.
Fixes: 75216638572f ("RDMA/cma: Export rdma cm interface to userspace") Reported-by: syzbot+dcfd344365a56fbebd0f@syzkaller.appspotmail.com Signed-off-by: Leon Romanovsky leonro@mellanox.com Reviewed-by: Sean Hefty sean.hefty@intel.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/core/ucma.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -494,6 +494,9 @@ err1: mutex_lock(&mut); idr_remove(&ctx_idr, ctx->id); mutex_unlock(&mut); + mutex_lock(&file->mut); + list_del(&ctx->list); + mutex_unlock(&file->mut); kfree(ctx); return ret; }